View source for Colorado potato beetle

{{Short description|Species of beetle}}
{{Redirect-distinguish-text|Potato beetle|the three-lined potato beetle, [[Lema daturaphila]]}}
{{for|other animals called potato bugs|Potato bug (disambiguation){{!}}Potato bug}}
{{Good article}}
{{Speciesbox
|name = Colorado potato beetle
|image = Colorado_potato_beetle.jpg
|genus = Leptinotarsa
|species = decemlineata
|authority = [[Thomas Say|Say]], 1824<ref>{{ITIS |id=720110 |taxon=''Leptinotarsa decemlineata'' |access-date=12 October 2017}}</ref>
|synonyms_ref = <ref>{{cite web |url=http://eol.org/pages/1171959/names/synonyms |title=''Leptinotarsa decemlineata'', Colorado Potato Beetle: Synonyms |publisher=[[Encyclopedia of Life]] |access-date=2017-07-19}}</ref>
|synonyms = *''Doryphora decemlineata'' <small>Say, 1824</small>
*''Stilodes decemlineata'' 
}}

The '''Colorado potato beetle''' ('''''Leptinotarsa decemlineata'''''; also known as the '''Colorado beetle''', the '''ten-striped spearman''', the '''ten-lined potato beetle''', and the '''potato bug''') is a [[beetle]] known for being a major [[Pest (organism)|pest]] of [[potato]] crops. It is about {{convert|10|mm|abbr=on|frac=8}} long, with a bright yellow/orange body and five bold brown stripes along the length of each of its [[elytron|wings]]. Native to the [[Rocky Mountains]], it spread rapidly in potato crops across the [[United States]] and then [[Europe]] from 1859 onwards.<ref name="Say-1824">{{cite journal |last1=Say |first1=Thomas |date=1824 |title=Descriptions of ''Coleopterous'' insects collected in the late expedition to the Rocky Mountains, performed by order of Mr. Calhoun, Secretary of War, under the command of Major Long |url=https://babel.hathitrust.org/cgi/pt?id=uc1.b4268076;view=1up;seq=443 |journal=Journal of the Academy of Natural Sciences of Philadelphia |volume=3 |issue=3 |pages=403–462}}; [https://babel.hathitrust.org/cgi/pt?id=uc1.b4268076;view=1up;seq=493 see pp. 453–454: "Doryphora, Illig.:  D. 10-lineata".]</ref>

The Colorado potato beetle was first observed in 1811 by [[Thomas Nuttall]] and was [[Species description|formally described]] in 1824 by American entomologist [[Thomas Say]].<ref name="Say-1824" /> The beetles were collected in the [[Rocky Mountains]], where they were feeding on the buffalo bur, ''[[Solanum rostratum]]''.<ref name="UoF" />

==Description==
Adult beetles typically are {{convert|6|-|11|mm|in|abbr=on}} in length and {{convert|3|mm|abbr=on}} in width. They weigh 50–170&nbsp;[[Milligram|mg]].<ref>{{cite web |title=Colorado Potato Beetle Facts |date=25 October 2018 |url=https://www.animalspot.net/colorado-potato-beetle.html |access-date=2021-02-20}}</ref> The beetles are orange-yellow in color with 10 characteristic black stripes on their front wings or [[elytra]]. The [[species|specific]] name ''decemlineata'', meaning "ten-lined", derives from this feature.<ref name='UoF' /><ref name='AgriCanada'>{{cite web |url=http://www.publications.gc.ca/collections/Collection/A43-1878-1992E.pdf |title=Colorado potato beetle LIFE STAGES |author1=Boiteau, G. |author2=Le Blanc, J.-P. R. |date=1992 |publisher=Agriculture Canada |access-date=2017-03-23}}</ref>

Adult beetles may be visually confused with ''L. juncta'', which is the [[false potato beetle]]. Unlike the Colorado potato beetle, it is not an agricultural pest. ''L.&nbsp;juncta'' also has alternating black and white strips on its back, but one of the white strips in the center of each wing cover is missing and replaced by a light brown strip.<ref>{{cite web |title=Species Leptinotarsa juncta – False Potato Beetle |url=http://bugguide.net/node/view/582 |website=BugGuide.Net |publisher=Iowa State University |access-date=18 October 2017}}</ref>

=== Larvae ===
The orange-pink larvae have a large, 9-segmented abdomen, black head, and prominent [[Spiracle (arthropods)|spiracles]], and may measure up to {{convert|15|mm|abbr=on}} in length in their final instar stage.

The beetle larva has four [[instar]] stages. The head remains black throughout these stages, but the pronotum changes colour from black in first- and second-instar larvae to having an orange-brown edge in its third-instar. In fourth-instar larvae, about half the pronotum is coloured light brown.<ref name="UoF">{{cite web |url=http://entomology.ifas.ufl.edu/creatures/veg/leaf/potato_beetles.htm |title=Featured creatures: ''Leptinotarsa'' spp. |publisher=University of Florida |date=2007 |access-date=2017-03-19}}</ref><ref>{{cite web |url=http://eol.org/pages/12049429/overview |title=Doryphorini |website=[[Encyclopedia of Life]] |access-date=2017-05-23}}</ref> This tribe is characterised within the subfamily by round to oval-shaped convex bodies, which are usually brightly coloured, simple claws which separate at the base, open cavities behind the procoxae, and a variable apical segment of the maxillary [[Pedipalp|palp]].<ref>{{cite book |author1=Jacques Jr., R. L. |date=1988 |title=The Potato Beetles: The genus Leptinotarsa in North America |publisher=Brill |isbn=978-0-916846-40-4}}</ref><ref name="AgriCanada" />

==Distribution==
The beetle is most likely native to the area between [[Colorado]] and [[northern Mexico]] and was discovered in 1824 by Thomas Say in the Rocky Mountains. It is found in North America and is present in every state and province except Alaska, California, Hawaii and Nevada.<ref name='UoF' /> It now has a wide distribution across Europe and Asia, totalling more than 16 million&nbsp;km<sup>2</sup>.<ref>{{cite web |date=2017 |title=Species ''Leptinotarsa decemlineata'' - Colorado Potato Beetle |url=http://bugguide.net/node/view/2706 |access-date=2017-03-19 |publisher=BugGuide}}</ref><ref>{{cite journal |author1=Weber, D. |date=2003 |title=Colorado beetle: pest on the move |journal=Pesticide Outlook |volume=14 |issue=6 |pages=256–259 |doi=10.1039/b314847p |url=https://naldc-legacy.nal.usda.gov/naldc/download.xhtml?id=36358&content=PDF |access-date=2018-12-29 |archive-date=2020-07-28 |archive-url=https://web.archive.org/web/20200728181258/https://naldc-legacy.nal.usda.gov/naldc/download.xhtml?id=36358&content=PDF |url-status=dead |url-access=subscription }}</ref>

Its first association with the potato plant (''[[Solanum tuberosum]]'') was not made until about 1859, when it began destroying potato crops in the region of [[Omaha]], [[Nebraska]]. Its spread eastward was rapid, at an average distance of 140&nbsp;km per year.<ref name='Feytaud'>{{cite book |author1=Feytaud, J. |title=La pomme de terre |publisher=Presses universitaires de France |year=1949 |pages=98–104 |language=fr}}</ref> The beetle has the potential to spread to temperate areas of East Asia, India, South America, Africa, New Zealand and Australia.<ref name="Alyokhin">{{cite book |author1=Alyokhin, A. |title=Potato II. Fruit, Vegetable and Cereal Science and Biotechnology 3 (Special Issue 1) |date=2009 |editor1=Tennant, P. |pages=10–19 |chapter=Colorado potato beetle management on potatoes: current challenges and future prospects |editor2=Benkeblia, N. |chapter-url=http://www.potatobeetle.org/Alyokhin_CPB_Review_reprint.pdf}}</ref>

=== Human interaction ===
By 1874 it had reached the Atlantic Coast.<ref name="UoF" /> From 1871  American entomologist [[Charles Valentine Riley]] warned Europeans about the potential for an accidental infestation caused by the transport of the beetle from America.<ref name="Feytaud" /> From 1875 several Western European countries, including Germany, Belgium, France and Switzerland, banned imports of American potatoes to avoid infestation by ''L. decemlineata''.<ref>{{cite book |author1=Sorensen, W. C. |title=Brethren of the net: American entomology, 1840-1880 |publisher=University of Alabama Press |series=History of American science and technology series |year=1995 |isbn=9780817307554 |pages=124–125}}</ref>

These controls proved ineffective, as the beetle soon reached Europe. In 1877 ''L. decemlineata'' reached the United Kingdom and was first recorded from [[Liverpool]] docks, but it did not become established. Many further outbreaks have occurred; the species has been eradicated in the UK at least 163 times. The last major outbreak was in 1977. It remains as a notifiable quarantine pest in the United Kingdom and is monitored by the Plant Health and Seeds Inspectorate of the Animal and Plant Health Agency (APHA) to prevent it from becoming established.<ref name='NNSS'>{{cite web |url=http://www.nonnativespecies.org//factsheet/factsheet.cfm?speciesId=1961 |title=Invasion history: Leptinotarsa decemlineata, Colorado Beetle |publisher=Non-Native Species Secretariat (DEFRA) |date=2017 |access-date=2017-03-20 |archive-date=2020-07-28 |archive-url=https://web.archive.org/web/20200728213628/http://www.nonnativespecies.org//factsheet/factsheet.cfm?speciesId=1961 |url-status=dead }}</ref> A [[cost-benefit]] analysis from 1981 suggested that the cost of the measures used to exclude ''L. decemlineata'' from the UK was less than the likely costs of control if it became established.<ref>{{cite journal |author1=Aitkenhead, P. |date=1981 |title=Colorado beetle - recent work in preventing its establishment in Britain |journal=Bulletin, Organisation Européenne et Méditerranéenne pour la Protection des Plantes |volume=11 |issue=3 |pages=225–234 |doi=10.1111/j.1365-2338.1981.tb01928.x}}</ref>

In July 2023 Colorado beetles were officially confirmed in a potato field in Kent, England. Farmers and growers, gardeners and members of the public are being encouraged to remain vigilant for signs of the pest and to report potential sightings to [[Animal and Plant Health Agency|APHA]].<ref>{{cite web|title=Why it is important to report possible Colorado beetle sightings to APHA|url=https://aphascience.blog.gov.uk/2024/05/07/why-it-is-important-to-report-possible-colorado-beetle-sightings-to-apha/|author=Lucy Carson-Taylor|author2=Victoria Tubman|date=7 May 2024|work=Animal and Plant Health Agency|publisher=His Majesty's Government}}</ref>

Elsewhere in Europe the beetle became established near USA military bases in [[Bordeaux]] during or immediately following [[World War I]] and had proceeded to spread by the beginning of World War II to Belgium, the Netherlands and Spain. The population increased dramatically during and immediately following World War II and spread eastward, and the beetle is now found over much of the continent. After [[World War II]], in the Soviet occupation zone of Germany, almost half of all potato fields were infested by the beetle by 1950. In [[East Germany]] they were known as ''Amikäfer'' ('Yankee beetles') following a governmental claim that the beetles were dropped by American planes. In the [[European Union]] it remains a regulated (quarantine) pest for the Republic of Ireland, Balearic Islands, Cyprus, Malta and southern parts of Sweden and Finland. It is not established in any of these member states, but occasional infestations can occur when, for example, wind blows adults from Russia to Finland.<ref>{{cite web |url=https://www.jyu.fi/en/news/archive/2014/07/tiedote-2014-07-24-09-54-43-153760 |author1=Lehmann, P. |title=The Colorado potato beetle is the grandmaster of adaptation |publisher=[[University of Jyväskylä]] |access-date=12 October 2017 |archive-date=2017-05-10 |archive-url=https://web.archive.org/web/20170510163454/https://www.jyu.fi/en/news/archive/2014/07/tiedote-2014-07-24-09-54-43-153760 |url-status=dead }}</ref><ref>{{cite web|url=https://www.evira.fi/en/plants/cultivation-and-production/plant-pests-and-diseases/quarantine-pests-and-diseases/frequently-asked-questions/the-colorado-beetle/|title=The Colorado beetle|publisher=Finnish Food Safety Authority|year=2016|access-date=12 October 2017|archive-url=https://web.archive.org/web/20180708015850/https://www.evira.fi/en/plants/cultivation-and-production/plant-pests-and-diseases/quarantine-pests-and-diseases/frequently-asked-questions/the-colorado-beetle/|archive-date=8 July 2018|url-status=dead}}</ref>

<gallery heights="180px" mode="packed">
File:kartoffelkaefer fg01e.jpg|Native range of the potato and native and current range of the Colorado beetle
File:Propagation du doryphore en Amérique du Nord.svg|Expansion of the Colorado potato beetle's range in North America, 1859–1876
File:Doryphore - expansion en Europe.svg|Expansion of the Colorado potato beetle's range in Europe, 1921–1964
</gallery>

==Lifecycle==
Colorado potato beetle females are very prolific and are capable of laying over 500 eggs in a 4- to 5-week period.<ref name='Kentucky'>{{cite web |url=https://entomology.ca.uky.edu/ef312 |title=Colorado Potato Beetle Management |author1=Bessin, R. |publisher=[[University of Kentucky]] College of Agriculture |access-date=2017-07-11}}</ref> The eggs are yellow to orange, and are about {{convert|1|mm|abbr=on}} long. They are usually deposited in batches of about 30 eggs on the underside of host leaves. Development of all life stages depends on temperature.

After 4–15 days, the eggs hatch into reddish-brown [[larva]]e with humped backs and two rows of dark brown spots, one row on each side. They feed on the leaves of their host plants. Larvae progress through four distinct growth stages ([[instar]]s). First instars measure about {{convert|1.50|mm|abbr=on}} long, and the last (fourth) instars about {{convert|8|mm|abbr=on}} long. The first through third instars each last about 2–3 days; the fourth lasts 4–7 days.

Upon reaching full size, each fourth instar spends several days as a nonfeeding [[prepupa]], which can be recognized by its inactivity and lighter coloration. The prepupae drop to the soil and burrow to a depth of several inches, then [[pupa]]te.<ref name="UoF" /> In 5 to 10 days, the adult beetle emerges to feed and mate. This beetle can thus go from egg to adult in as little as 21 days.<ref name="Kentucky" /> Depending on temperature, light conditions, and host quality, the adults may enter [[diapause]] and delay emergence until spring. They then return to their host plants to mate and feed; overwintering adults may begin mating within 24 hours of spring emergence.<ref>{{cite journal |author1=Ferro, D. N. |author2=Alyokhin, A. V. |author3=Tobin, D. B. |year=1999 |title=Reproductive status and flight activity of the overwintered Colorado potato beetle |journal=Entomologia Experimentalis et Applicata |volume=91 |issue=3 |pages=443–448 |doi=10.1046/j.1570-7458.1999.00512.x|bibcode=1999EEApp..91..443F |s2cid=85300335 }}</ref> In some locations, three or more generations may occur each growing season.<ref name="UoF" />

<gallery heights="120px" mode="packed">
File:Leptinotarsa-decemlineata-eggs.jpg|Eggs laid on the underside of a leaf
File:Leptinotarsa decemlineata UGA1243045.jpg|1st instar larva after hatching
File:Potato beetle larvae.jpg|3rd instar stage of larvae
File:2006-07-16 larve2.jpg|4th instar stage of larva, before pupation
File:Leptinotarsa decemlineata UGA1243047 - no watermark.jpg|Pupa
File:Kartoffelkäfer.jpg|Adult beetle after emergence
File:Leptinotarsa decemlineata, A Coruña, Galiza.jpg|Mating adult beetles
</gallery>

=== Mate and host searching ===
Visual cues are important for Colorado potato beetles during the mate and host search. In a study done by Szentsi, Weber, and Jermy in the paper ''Role of visual stimuli in host and mate location of the Colorado potato beetle,'' the beetles' attraction to boards with different spectral bands, reaction to beetle-sized stationary objects, responses to such objects on boards, and attraction to prior female substances were investigated.<ref name=":1" /> The researchers' hypothesis was that experience with female substances would cause behavior changes in males.<ref name=":1">{{Cite journal |last1=Szentesi |first1=Á. |last2=Weber |first2=D. C. |last3=Jermy |first3=T. |date=October 2002 |title=Role of visual stimuli in host and mate location of the Colorado potato beetle |url=https://onlinelibrary.wiley.com/doi/10.1046/j.1570-7458.2002.01042.x |journal=Entomologia Experimentalis et Applicata |language=en |volume=105 |issue=2 |pages=141–152 |doi=10.1046/j.1570-7458.2002.01042.x |bibcode=2002EEApp.105..141S |s2cid=18061915 |issn=0013-8703|url-access=subscription }}</ref> When shown colored boards, the beetles had a positive response between 45° and 0° in terms of mean angular directions (MADs).<ref name=":1" /> Beads and dead beetles without boards evoked a weaker response with MADs being variable. Colored boards and bead combinations displayed more positive MADs responses between 45° and 0°.<ref name=":1" /> Experience with female substances showed that male beetles showed high responses to female scent. According to the study, 43 of the 49 runs where female smear was used had a response score of 5 in contrast to the 23/42 runs without female smear receiving a score of 5.<ref name=":1" />

Colorado potato beetles are also attracted to the volatiles potato plants emit.<ref name=":2">{{Cite journal |last=Dickens |first=Joseph C. |date=2007-10-01 |title=Sexual contact influences orientation to plant attractant in Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) |url=https://doi.org/10.1007/s00114-007-0261-z |journal=Naturwissenschaften |language=en |volume=94 |issue=10 |pages=847–852 |doi=10.1007/s00114-007-0261-z |pmid=17563865 |bibcode=2007NW.....94..847D |s2cid=13479023 |issn=1432-1904|url-access=subscription }}</ref> In the article ''Sexual contact influences orientation to plant attractant in Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae)'' by Joseph Dickens, the beetles were attracted to [[kairomone]] substance but after mating, their attraction to it reduced. Within 24 hours of mating, there was no difference between levels of attraction to kairomone and control solvent.<ref name=":2" /> Lack of attraction occurred for two days but resumed three days after mating. Male beetles produce a pheromone that is further enhanced by plant host volatiles like the kairomone. After a beetle is attracted to the host, mating occurs and the female lays her eggs on the plant.<ref name=":2" /> The beetles' attraction to kairomone decreases until 72 hours later once oviposition occurs and the probability of re-mating increases.<ref name=":2" />

==Behavior and ecology==
===Diet===
''L. decemlineata'' has a strong association with plants in the family [[Solanaceae]], particularly those of the genus ''[[Solanum]]''. It is directly associated with ''[[Solanum rostratum|Solanum cornutum]]'' (buffalo-bur), ''[[Solanum nigrum]]'' (black nightshade), ''[[Solanum melongena]]'' (eggplant or aubergine), ''[[Solanum dulcamara]]'' (bittersweet nightshade), ''[[Solanum luteum]]'' (hairy nightshade), ''[[Solanum tuberosum]]'' (potato), and ''[[Solanum elaeagnifolium]]'' (silverleaf nightshade). They are also associated with other plants in this family, namely the species ''[[Solanum lycopersicum]]'' (tomato) and the genus ''[[Capsicum]]'' (pepper).<ref>{{cite web|url=http://www.brc.ac.uk/dbif/invertebratesresults.aspx?insectid=4742 |title=Leptinotarsa decemlineata (Say) |publisher=Biological Records Centre -Database of Insects and their Food Plants |access-date=2017-03-24}}</ref>

===Enemies===

[[File:Coleomegilla maculata UGA1475029.jpg|thumb|''[[Coleomegilla maculata]]'' preying upon Colorado beetle eggs]]

At least 13 insect genera, three spider [[Family (biology)|families]], one phalangid ([[Opiliones]]), and one [[mite]] have been recorded as either generalist or specialized predators of the varying stages of ''L. decemlineata''. These include the [[Carabidae|ground beetle]] ''[[Lebia grandis]]'', the [[Coccinellidae|coccinellid]] beetles ''[[Coleomegilla maculata]]'' and ''[[Hippodamia convergens]]'', the [[Pentatomidae|shield bugs]] ''[[Perillus bioculatus]]'' and ''[[Spined soldier bug|Podisus maculiventris]]'',  various species of the [[lacewing]] genus ''[[Chrysopa]]'', the [[Vespidae|wasp]] genus ''[[Polistes]]'', and the [[Nabidae|damsel bug]] genus ''[[Nabis (bug)|Nabis]]''.<ref>{{cite journal |author1=Hilbeck, A. |author2=Kennedy, G. G. |date=1996 |title=Predators Feeding on the Colorado Potato Beetle in Insecticide-Free Plots and Insecticide-Treated Commercial Potato Fields in Eastern North Carolina |journal=Biological Control |volume=6 |issue=2 |pages=273–282 |doi=10.1006/bcon.1996.0034|bibcode=1996BiolC...6..273H }}</ref>

The predatory ground beetle ''L. grandis'' is a predator of both the eggs and larvae of ''L. decemlineata'', and its larvae are [[parasitoid]]s of the pupae. An adult ''L. grandis'' may consume up to 23 eggs or 3.3 larvae in a single day.<ref>{{cite journal |author1=Weber, D. C. |author2=Rowley, D. L. |author3=Greenstone, M. H. |author4=Athanas, M. M. |date=2006 |title=Prey preference and host suitability of the predatory and parasitoid carabid beetle, Lebia grandis, for several species of Leptinotarsa beetles |journal=[[Journal of Insect Science (Entomological Society of America)|Journal of Insect Science]] |volume=6 |issue=9 |pages=1–14 |pmc=2990295 |doi=10.1673/1536-2442(2006)6[1:ppahso]2.0.co;2 |pmid=19537994}}</ref>

In a laboratory experiment, ''Podisus maculiventris'' was used as a predatory threat to female ''L. decemlineata'' specimens, resulting in the production of unviable [[trophic egg]]s alongside viable ones; this response to a predator ensured that additional food was available for newly hatched offspring to increase their survival rate. The same experiment also demonstrated the cannibalism of unhatched eggs by newly hatched ''L. decemlineata'' larvae as an antipredator response.<ref>{{cite journal |author1=Tigreros, N. |author2=Norris, R. H. |author3=Wang, E. |author4=Thaler, J. S. |date=2017 |title=Maternally induced intraclutch cannibalism: an adaptive response to predation risk? |journal=[[Ecology Letters]] |volume=20 |issue=4 |pages=487–494 |doi=10.1111/ele.12752|pmid=28295886 |bibcode=2017EcolL..20..487T }}</ref>

{| class="wikitable" style="margin-left: auto; margin-right: auto; border: none;"
|+ Examples of parasitoids, predators, and pathogens of different life stages of ''Leptinotarsa decemlineata'' {{Ref|Note1|1}}
! Type !! Species !! Order !! Predates !! Location !! Reference
|-
! [[Parasitoid]]
| ''[[Chrysomelobia labidomerae]]''
| [[Acari]]
| Adults
| USA, Mexico
|<ref>{{cite journal |author1=Drummond, F. A. |author2=Casagrande, R. A. |author3=Logan, P. A. |title=Impact of the parasite, Chrysomelobia labidomerae Eickwort, on the Colorado potato beetle |journal=[[International Journal of Acarology]] |volume=18 |year=1992 |issue=2 |pages=107–115 |doi=10.1080/01647959208683940|bibcode=1992IJAca..18..107D |url=https://digitalcommons.uri.edu/pls_facpubs/115 }}</ref>
|-
! 
| ''[[Edovum puttleri]]''
| [[Hymenoptera]]
| Eggs
| USA, Mexico, Colombia
|<ref>{{cite journal |author1=Grissell, E. E. |title=Edovum puttleri, n.g., n.sp. (Hymenoptera: Eulophidae), an egg parasite of the Colorado potato beetle (Chrysomelidae) |year=1981 |journal=Proceedings of the Entomological Society of Washington |volume=83 |issue=4 |pages=790–796}}</ref>
|-
|-
! 
| ''[[Anaphes flavipes]]''
| [[Hymenoptera]]
| Eggs
| USA
| 
|-
! 
| ''[[Myiopharus aberrans]]''
| [[Diptera]]
| Eggs
| USA
| 
|-
! 
| ''[[Myiopharus doryphorae]]''
| [[Diptera]]
| Larvae
| USA, Canada
| 
|-
! 
| ''[[Meigenia mutabilis]]''
| [[Diptera]]
| Larvae
| Russia
| 
|-
! 
| ''[[Megaselia rufipes]]''
| [[Diptera]]
| Adults
| Germany
| 
|-
! 
| ''[[Heterorhabditis bacteriophora]]''
| [[Nematoda]]
| Adults
| Cosmopolitan
|<ref>{{cite journal |author1=Ebrahimi, L. |author2=Niknam, G. |author3=Dunphy, G. B. |title=Hemocyte Responses of the Colorado Potato Beetle, Leptinotarsa decemlineata, and the Greater Wax Moth, Galleria mellonella, to the Entomopathogenic Nematodes, Steinernema feltiae and Heterorhabditis bacteriophora |year=2011 |journal=Journal of Insect Science |volume=11 |issue=1 |doi=10.1673/031.011.7501 |pmid=21867441 |pages=1–13|pmc=3281463 }}</ref>
|-
! 
| ''[[Heterorhabditis heliothidis]]''
| [[Nematoda]]
| Adults
| Cosmopolitan
| 
|-
! [[Predator]]
| ''[[Lebia grandis]]''
| [[Coleoptera]]
| Eggs, Larvae, Adults
| USA
| 
|-
! 
| ''[[Hippodamia convergens]]''
| [[Coleoptera]]
| Eggs, Larvae
| USA, Mexico
| 
|-
! 
| ''[[Euthyrhynchus floridanus]]''
| [[Hemiptera]]
| Larvae
| USA
|<ref>{{cite journal |author1=Chittenden, F. H. |year=1911 |title=On the natural enemies of the Colorado potato beetle |journal=Bulletin United States Department of Agriculture, Bureau of Entomology |volume=82 |pages=85–88}}</ref>
|-
! 
| ''[[Oplomus dichrous]]''
| [[Hemiptera]]
| Eggs, Larvae
| USA, Mexico
|<ref>{{cite journal |author1=Drummond, F. A. |author2=Casagrande, R. A. |author3=Groden, E. |title=Biology of Oplomus dichrous (Heteroptera: Pentatomidae) and Its Potential to Control Colorado Potato Beetle (Coleoptera: Chrysomelidae) |journal=Environmental Entomology |volume=16 |issue=3 |date=1987 |pages=633–638 |doi=10.1093/ee/16.3.633}}</ref>
|-
! 
| ''[[Perillus bioculatus]]''
| [[Hemiptera]]
| Eggs, Larvae, Adults
| USA, Mexico, Canada
|<ref>{{cite journal |title=Biological Control of the Colorado Potato Beetle Leptinotarsa Decemlineata (Coleoptera: Chrysomelidae) in Quebec by Augmentative Releases of the Two-Spotted Stinkbug Perillus Bioculatus (Hemiptera: Pentatomidae) |author1=Cloutier, C. |author2=Bauduin, F. |journal=The Canadian Entomologist |volume=127 |issue=2 |date=1995 |pages=195–212 |doi=10.4039/ent127195-2|s2cid=85720476 }}</ref>
|-
! 
| ''[[Podisus maculiventris]]''
| [[Hemiptera]]
| Larvae
| USA
|<ref>{{cite web |url=http://edis.ifas.ufl.edu/pdffiles/IN/IN38700.pdf |title=Spined Soldier Bug, Podisus maculiventris (Say) |author1=Richman, D. B. |author2=Mead, F. W. |author3=Fasulo, T. R. |publisher=University of Florida, IFAS Extension |access-date=2017-07-31}}</ref>
|-
! 
| ''[[Pselliopus cinctus]] ''
| [[Hemiptera]]
| Larvae
| USA
|
|-
! 
| ''[[Sinea diadema]]''
| [[Hemiptera]]
| Larvae
| USA
| 
|-
! 
| ''[[Stiretrus anchorago]]''
| [[Hemiptera]]
| Larvae
| USA, Mexico
| 
|-
! [[Pathogen]]
| ''[[Bacillus thuringiensis]]'' <br />subsp. ''tenebrionis''
| [[Bacillales]]
| Larvae
| USA, Canada, Europe
| 
|-
! 
| ''[[Photorhabdus luminescens]]''
| [[Enterobacterales]]
| Adults, Larvae
| Cosmopolitan
|<ref>{{cite journal |author1=Blackburn, M. B. |author2=Domek, J. M |author3=Gelman, D. B |author4=Hu, J. S. |date=2005 |title=The broadly insecticidal Photorhabdus luminescens toxin complex a (Tca): activity against the Colorado potato beetle, Leptinotarsa decemlineata, and sweet potato whitefly, Bemisia tabaci |journal=Journal of Insect Science |volume=5 |issue=1 |page=32 |doi=10.1093/jis/5.1.32|pmc=1615239 |pmid=17119614}}</ref>
|-
! 
| ''[[Spiroplasma]]''
| [[Entomoplasmatales]]
| Adults, Larvae
| North America, Europe
|<ref>{{cite web |url=http://ecoport.org/ep?Arthropod=26353&entityType=AR****&entityDisplayCategory=full |author1=Breithaupt, J. |title=Leptinotarsa decemlineata: Management |date=4 November 2012 |publisher=Ecoport |access-date=2017-07-28}}</ref>
|-
! 
| ''[[Beauveria bassiana]]''
| [[Hypocreales]]
| Adults, Larvae
| USA
|<ref>{{cite book |author1=Bonnemaison, L. |date=1961 |title=Les ennemis animaux des plantes cultivées et des forêts, vol. II |page=98 |language=fr}}</ref>
|-
|}

=== Sexual dimorphism ===
Colorado potato beetles exhibit [[sexual dimorphism]]. In particular, they exhibit dimorphism in the adhesive tarsal setae.<ref name=":0">{{Cite journal |last1=Voigt |first1=D. |last2=Schuppert |first2=J. M. |last3=Dattinger |first3=S. |last4=Gorb |first4=S. N. |date=2008-05-01 |title=Sexual dimorphism in the attachment ability of the Colorado potato beetle Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) to rough substrates |url=https://www.sciencedirect.com/science/article/pii/S0022191008000279 |journal=Journal of Insect Physiology |volume=54 |issue=5 |pages=765–776 |doi=10.1016/j.jinsphys.2008.02.006 |pmid=18387627 |bibcode=2008JInsP..54..765V |issn=0022-1910|url-access=subscription }}</ref> The paper "Sexual dimorphism in the attachment ability of the Colorado potato beetle Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) to rough substrates" by Voigt demonstrates this dimorphism. The [[seta]]e, hair-like structures, in males is to help them adhere to the females' elytra when mating. Colorado potato beetles also have adhesive setae that allows them to attach to host plants.<ref name=":0" />

Three current setae are known: simple pointed with an asymmetric narrowing at the tip (males and females), spatula-like with a pin on its dorsal surface (males and females), setae with an adhesive terminal disc (males only).<ref name=":0" /> Male setae are better designed for smooth surfaces; male Colorado potato beetles have been observed attaching onto smooth glass and plastic surfaces and also attach to the smooth female elytra.

Microscopy of the tarsal reveals five articulated [[Arthropod leg|tarsomeres]] and paired curved claws.<ref name=":0" /> Males and females have an adhesive setae covering the first three tarsomeres. The fourth is hidden and the fifth bears sensory setae with no adhesive function. Both males and females have filamentous with a tapered terminal part, lanceolate with a flattened tapered terminal part, and spatula-shaped with an enlarged tape-like terminal part.<ref name=":0" /> Males have a discoidal terminal part with a bulge around the disc. Female elytra appears smooth on the surface, but further magnification shows irregular lines. This indicates fluid on the elytra.<ref name=":0" />

== Genetics ==

=== Genetic differentiation from agriculture ===
Colorado potato beetles display genetic differentiation based on region. In the [[Columbia Basin Project|Columbia Basin]] and Central Sands, beetles in the Columbia Basin had less genetic diversity than those in Central Sands. According to the study done by Crossly, Rondon, and Schoville, in the paper ''Effects of contemporary agricultural land cover on Colorado potato beetle genetic differentiation in the Columbia Basin and Central Sands''',''''' nucleotide diversity in the Columbia Basin beetles ranged from 0.0056-0.0063 and 0.0073-0.0080 in Central Sands. Heterozygosity data showed the Columbia Basin was 19.4% ± 0.4% and 21.6% ± 0.8% in the Central Sands.<ref name="ReferenceA">{{Cite journal |last1=Crossley |first1=Michael S. |last2=Rondon |first2=Silvia I. |last3=Schoville |first3=Sean D. |date=August 2019 |title=Effects of contemporary agricultural land cover on Colorado potato beetle genetic differentiation in the Columbia Basin and Central Sands |journal=Ecology and Evolution |language=en |volume=9 |issue=16 |pages=9385–9394 |doi=10.1002/ece3.5489 |issn=2045-7758 |pmc=6706216 |pmid=31463029|bibcode=2019EcoEv...9.9385C }}</ref> Additional [[Mitochondrial DNA|mitochondrial DNA sequencing]] showed two haplotypes in the Columbia Basin compared to places like Wisconsin showed seven haplotypes.

Reasoning behind the genetic diversity is the landscapes of the regions: shrub-land and grains in the Columbia Basin versus the forest, corn, and beans in the Central Sands. In the same study, potatoes covered 3.5% in the Columbia Basin and 1.8% in the Central Sands.<ref name="ReferenceA"/> Landscape resistance can be characterized by how the land responds to the spread of beetles. Its overall effect on allele frequency covariance was low, and the Central Sands had a higher rate of decay in allele frequency. Potatoes' relative effect sizes of land cover variables on genetic differentiation was the highest in the Columbia Basin. However, when comparing all the land types, no particular land cover displayed any significant difference from the others.<ref>{{Cite journal |last1=Crossley |first1=Michael S. |last2=Rondon |first2=Silvia I. |last3=Schoville |first3=Sean D. |date=August 2019 |title=Effects of contemporary agricultural land cover on Colorado potato beetle genetic differentiation in the Columbia Basin and Central Sands |journal=Ecology and Evolution |language=en |volume=9 |issue=16 |pages=9385–9394 |doi=10.1002/ece3.5489 |pmid=31463029 |pmc=6706216 |bibcode=2019EcoEv...9.9385C |issn=2045-7758}}</ref>

Genetic differentiation in the Colorado potato beetle can be impacted by agricultural practices such as [[crop rotation]]. The same study mentioned earlier examines crop rotation's effects on genetic differentiation in Colorado potato beetles that were not found in the Central Sands. On the other hand, genetic diversity decreased with increased crop rotation in the Columbia Basin.<ref name="ReferenceA"/> This difference could be attributed to larger rotation differences in the Columbia Basin or differences in the landscape itself that affect the spread of the beetles. Genetic diversity is not directly impacted by the land cover type. Instead, other factors such as climate could be responsible for the differences between the Colorado potato beetle in these two regions.<ref name="ReferenceA"/>

=== Genetic differentiation due to invasion ===
The Colorado potato beetle has invaded North America and Europe. Because of its widespread invasion, the Colorado potato beetle displays genetic diversity in its different regions. In the paper ''The voyage of an invasive species across continents: genetic diversity of North American and European Colorado potato beetle populations'' by Grapputo, Boman, Lindström, and Mappes, sequencing of amplified mtDNA from 109 beetles in 13 populations showed 20 unique haplotypes.<ref name=":3">{{Cite journal |last1=Grapputo |first1=Alessandro |last2=Boman |first2=Sanna |last3=LindströM |first3=Leena |last4=Lyytinen |first4=Anne |last5=Mappes |first5=Johanna |date=December 2005 |title=The voyage of an invasive species across continents: genetic diversity of North American and European Colorado potato beetle populations |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1365-294X.2005.02740.x |journal=Molecular Ecology |language=en |volume=14 |issue=14 |pages=4207–4219 |doi=10.1111/j.1365-294X.2005.02740.x |pmid=16313587 |bibcode=2005MolEc..14.4207G |s2cid=1146330 |issn=0962-1083|url-access=subscription }}</ref> Three haplotypes were shared in the populations and all others were restricted to a single population in North America. 51 European beetles collected from eight populations yielded in one haplotype that was also fixed in the Idaho population.<ref name=":3"/> Mitochondrial data, [[Mitochondrial DNA|mtDNA]],  of North American beetles showed significant population differentiation. For example, 44% of the variation can be attributed to subdivision among populations, especially in Kentucky and Idaho.<ref name=":3"/>

[[Polymorphism (biology)|Polymorphism]] was highest in Colorado potato beetles in Colorado and the lowest was in France. Polymorphism and [[Zygosity|heterozygosity]] was higher in North America than in Europe. Heterozygosity ranged from 0.25 in New Brunswick to 0.14 in France.<ref name=":3"/> Further analysis revealed population differentiations between North America and Europe. There were two separate groups of European beetles, one formed by western European beetles and the second being eastern European beetles. 13% of total variation is from variation among the two continent groups, and 17% of variation is from population variance within groups.<ref name=":3"/> Beetles from North American and Europe formed clusters. With the exception of New Brunswick and Kentucky beetles, most beetles from the same population cluster together. In Europe, there were more complex relations between the beetles. Estonian and Spanish beetles clustered, French and Italian beetles formed separate groups, and Russian and Finnish beetles were closely related to Estonian ones.<ref name=":3" /> European beetles could be categorized by East and West except for Polish beetles which had relations to multiple countries.<ref name=":3" />

===Importance of transposable elements in genome===
To help explain why Colorado Potato beetles are such difficult agricultural pests to manage and control, a group of researchers sought to test both structural and functional genetic changes in the species of beetle as compared to other arthropod species. Using community annotation, transcriptomics, and genome sequencing, they uncovered that Colorado Potato beetles have a genome consisting of several transposable elements.<ref name=":new2">{{cite journal |last1=Schoville |first1=Sean D. |last2=Chen |first2=Yolanda H. |last3=Andersson |first3=Martin N. |last4=Benoit |first4=Joshua B. |last5=Bhandari |first5=Anita |last6=Bowsher |first6=Julia H. |last7=Brevik |first7=Kristian |last8=Cappelle |first8=Kaat |last9=Chen |first9=Mei-Ju M. |last10=Childers |first10=Anna K. |last11=Childers |first11=Christopher |last12=Christiaens |first12=Olivier |last13=Clements |first13=Justin |last14=Didion |first14=Elise M. |last15=Elpidina |first15=Elena N. |last16=Engsontia |first16=Patamarerk |last17=Friedrich |first17=Markus |last18=García-Robles |first18=Inmaculada |last19=Gibbs |first19=Richard A. |last20=Goswami |first20=Chandan |last21=Grapputo |first21=Alessandro |last22=Gruden |first22=Kristina |last23=Grynberg |first23=Marcin |last24=Henrissat |first24=Bernard |last25=Jennings |first25=Emily C. |last26=Jones |first26=Jeffery W. |last27=Kalsi |first27=Megha |last28=Khan |first28=Sher A. |last29=Kumar |first29=Abhishek |last30=Li |first30=Fei |last31=Lombard |first31=Vincent |last32=Ma |first32=Xingzhou |last33=Martynov |first33=Alexander |last34=Miller |first34=Nicholas J. |last35=Mitchell |first35=Robert F. |last36=Munoz-Torres |first36=Monica |last37=Muszewska |first37=Anna |last38=Oppert |first38=Brenda |last39=Palli |first39=Subba Reddy |last40=Panfilio |first40=Kristen A. |last41=Pauchet |first41=Yannick |last42=Perkin |first42=Lindsey C. |last43=Petek |first43=Marko |last44=Poelchau |first44=Monica F. |last45=Record |first45=Éric |last46=Rinehart |first46=Joseph P. |last47=Robertson |first47=Hugh M. |last48=Rosendale |first48=Andrew J. |last49=Ruiz-Arroyo |first49=Victor M. |last50=Smagghe |first50=Guy |last51=Szendrei |first51=Zsofia |last52=Thomas |first52=Gregg W. C. |last53=Torson |first53=Alex S. |last54=Vargas Jentzsch |first54=Iris M. |last55=Weirauch |first55=Matthew T. |last56=Yates |first56=Ashley D. |last57=Yocum |first57=George D. |last58=Yoon |first58=June-Sun |last59=Richards |first59=Stephen |title=A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) |journal=Scientific Reports |date=31 January 2018 |volume=8 |issue=1 |pages=1931 |doi=10.1038/s41598-018-20154-1 |pmid=29386578 |pmc=5792627 |bibcode=2018NatSR...8.1931S |language=en |issn=2045-2322|hdl=1854/LU-8552281 |hdl-access=free }}</ref> Transposons are sequences of genetic material that can shift/move their place within an organism's genome, and 17% of the Colorado Potato beetles’ genome consists of transposable elements.<ref name=":new2" /> This helps explain their rapid evolution to continually resist insecticides, contributing to their global spread.

==As an agricultural pest==
[[File:Aardappelvijand nr 1 de coloradokever-526506.ogv|thumb|Dutch newsreel from 1947]]

=== Factors affecting beetle dispersal ===
Colorado potato beetles are highly mobile and are considered pests. Colorado potato beetles disperse to hosts via walking and flight. Flights have three types: short, long, and diapause. Diapause is a long-distance flight that occurs at the end of the summer.<ref name=":4">{{Cite journal |last1=Boiteau |first1=G. |last2=Alyokhin |first2=A. |last3=Ferro |first3=D. N. |date=February 2003 |title=The Colorado potato beetle in movement |url=https://www.cambridge.org/core/journals/canadian-entomologist/article/abs/colorado-potato-beetle-in-movement/556BCFA74DC6463C99F4FADA47859024 |journal=The Canadian Entomologist |language=en |volume=135 |issue=1 |pages=1–22 |doi=10.4039/n02-008 |s2cid=84276356 |issn=1918-3240|url-access=subscription }}</ref> In order for dispersal to occur, certain conditions need to be met, both abiotic and biotic.

=== Abiotic conditions ===
Abiotic factors include temperature, photoperiod, insolation, wind, and gravity. A soil temperature of 9&nbsp;°C causes soiled beetles to move up. They emerge when soil surface temperature is 14–15&nbsp;°C.<ref name=":4" /> Optimal flight takeoff temperature is 27&nbsp;°C. Long [[Photoperiodism|photoperiods]] enable proper flight-muscle development. Insolation is also important for flight; at least 6&nbsp;hours of insolation paired with 25–28&nbsp;°C temperatures are optimal for takeoff.<ref name=":4" /> Wind is another condition that needs to be met. Speeds of 1–3&nbsp;m/s assist with takeoff for short-distance flights. Gravity can also affect flight speed in the beetles; as the Colorado potato beetle moves out of soil, it does so on slopes of 20° or more.<ref name=":4" />

=== Biotic conditions ===
Biotic conditions include availability of energy reserves, insect weight, insect density, overwintered adults, and summer adults. It is speculated that proline is the primary energy substance for Colorado potato beetles in flight. Beetles that gain more than 15% of their weight after emerging fly less and for shorter distances than beetles that remain the same weight.<ref name=":4" /> Wing loadings for male and female beetles were 10.83 and 15.60 N/m<sup>2</sup>.<ref name=":4" /> Wing loading changes as beetles feed, drink, and develop eggs. Cases of large groups of beetles leaving crops have been observed when there is higher population density. However, this is likely due to destruction of the food source, not the population itself. Overwintered beetles exhibit different behavior than summer beetles.<ref name=":4" /> They typically fly less because it is an adaptation to the higher risks of food deprivation in the spring compared to summer. During the summer, the adults that emerge walk until they eat enough to develop proper flight muscles and develop a proper elytra.<ref name=":4" />

=== Motivations for dispersal and stimuli ===
Colorado potato beetles walk in orientations to find food. In the dark, they walk at slow speeds and in circles. Beetles also move in response to olfactory cues.<ref name=":4" /> The beetles respond and move faster to familiar odors. Depending on satiation levels, the beetles move differently with the winds. A parallel walk with the wind is found in satiated beetles whereas starved beetles walk against it.<ref name=":4" />

Visual cues are also important for the beetles. Colorado potato beetles respond to light, and intensity is proportional to rest period. Beetles exhibit phototactic orientation in which they align themselves with a cone of light and move with it. Compass orientation is when large amounts of beetles walk in a single direction and have memory of their angle to the sun.<ref name=":4" />

The rate of linear displacement is important for the probability of the beetle finding a plant, mate, or habitat. This is important for the success of orientation mechanisms.<ref name=":4" />

New beetles disperse for crops once they emerge. The crops affect colonization: [[crop rotation]] prolongs colonization, and neighboring crops are colonized rapidly and by walking.<ref name=":4" /> Overwintered beetles fly to find crops and once a host plant is found, flight frequency decreases. The strategy behind this is thought to be minimizing reproductive risk because female beetles that emerge in the spring are already mated.<ref name=":4" /> Dispersal continues after finding a host. Moving helps beetles find better resources, mates, and progeny distribution. When moving, flight is less frequent than walking in cultivated fields than in the wild.<ref name=":4" />

Researchers have also evaluated how flight frequency is related to the beetle's diet. In a beetle population that had returned from diapause and been exposed to poor food conditions, mean flight frequency was decreased. This is because beetles required better food conditions to regenerate their flight muscles. Prior to diapause, beetles increased their flight frequency to compensate for poor food conditions.<ref>{{Cite journal |last1=MacQuarrie |first1=Chris J. K. |last2=Boiteau |first2=Gilles |date=2003-05-22 |title=Effect of diet and feeding history on flight of Colorado potato beetle, Leptinotarsa decemlineata |url=https://onlinelibrary.wiley.com/doi/10.1046/j.1570-7458.2003.00058.x |journal=Entomologia Experimentalis et Applicata |language=en |volume=107 |issue=3 |pages=207–213 |doi=10.1046/j.1570-7458.2003.00058.x |bibcode=2003EEApp.107..207M |issn=0013-8703}}</ref>

===Potato crop pest===
Around 1840, ''L. decemlineata'' adopted the cultivated potato into its host range and it rapidly became a most destructive pest of potato crops.<ref>{{Cite journal |last=Clark |first=J. F. M. |date=April 2007 |title="The eyes of our potatoes are weeping": the rise of the Colorado beetle as an insect pest |url=https://www.euppublishing.com/doi/10.3366/anh.2007.34.1.109 |journal=Archives of Natural History |language=en |volume=34 |issue=1 |pages=109–128 |doi=10.3366/anh.2007.34.1.109 |issn=0260-9541|url-access=subscription }}</ref> It is today considered to be the most important insect defoliator of potatoes.<ref name='Alyokhin' /> It may also cause considerable damage to tomato and aubergine crops with both adults and larvae feeding on the plant's foliage. Larvae may defoliate potato plants resulting in yield losses up to 100% if the damage occurs prior to tuber formation.<ref name='TheInsects'>{{cite book |editor1=Gullan, P. J. |editor2=Cranston, P. S. |date=1994 |chapter=15.2.1 Insecticide resistance |title=The Insects: An Outline of Entomology |publisher=[[Chapman & Hall]] |pages=404–407 |isbn=978-0-412-49360-7}}</ref> Larvae may consume 40&nbsp;cm<sup>2</sup> of potato leaves during the entire larval stage, but adults are capable of consuming 10&nbsp;cm<sup>2</sup> of foliage per day.<ref>{{cite journal |author1=Ferro, D. N. |author2=Logan, J. A. |author3=Voss, R. H. |author4=Elkinton, J. S. |date=1985 |title=Colorado potato beetle (Coleoptera: Chrysomelidae) temperature-dependent growth and feeding rates |journal=Environmental Entomology |volume=14 |issue=3 |pages=343–348 |doi=10.1093/ee/14.3.343}}</ref>

The economic cost of insecticide resistance is significant, but published data on the subject are minimal.<ref>{{cite web |url=http://www.plantwise.org/KnowledgeBank/Datasheet.aspx?dsid=30380 |title=Plantwise Technical Factsheet, Colorado potato beetle (Leptinotarsa decemlineata) |publisher=[[Plantwise]] |access-date=2017-07-19}}</ref> In 1994, total costs of the insecticide and crop losses in the US state of Michigan were $13.3 million, representing 13.7% of the total value of the crop. The estimate of the cost implication of insecticides and crop losses per [[hectare]] is $138–368. Long-term increased cost to the Michigan potato industry caused by insecticide resistance in Colorado potato beetle was estimated at $0.9 to $1.4 million each year.<ref>{{cite journal |author1= Grafius, E. |date=1997 |title=Economic Impact of Insecticide Resistance in the Colorado Potato Beetle (Coleoptera: Chrysomelidae) on the Michigan Potato Industry |journal=Journal of Economic Entomology |volume=90 |issue=5 |pages=1144–1151 |doi=10.1093/jee/90.5.1144|doi-access=free }}</ref>

=== Potato protection ===
[[File:ColoradoBeetleLateStageLarvaEating.jpg|thumb|A Colorado beetle larva eating a leaf of a potato plant]]
Colorado potato beetles pose significant dangers to potatoes, which are a quintessential agricultural crop. In response to the damage they do, some potatoes have been genetically modified to resist attack and damage from the beetles.<ref name=":6">{{Cite journal |last1=Perlak |first1=Frederick J. |last2=Stone |first2=Terry B. |last3=Muskopf |first3=Yvonne M. |last4=Petersen |first4=Lisa J. |last5=Parker |first5=Gregory B. |last6=McPherson |first6=Sylvia A. |last7=Wyman |first7=Jeff |last8=Love |first8=Stephen |last9=Reed |first9=Gary |last10=Biever |first10=Duane |last11=Fischhoff |first11=David A. |date=1993-05-01 |title=Genetically improved potatoes: protection from damage by Colorado potato beetles |url=https://doi.org/10.1007/BF00014938 |journal=Plant Molecular Biology |language=en |volume=22 |issue=2 |pages=313–321 |doi=10.1007/BF00014938 |pmid=8507832 |bibcode=1993PMolB..22..313P |issn=1573-5028|url-access=subscription }}</ref> Specifically, the [[Russet Burbank|Russet Burbank Potato]]. The insertion of a ''cryIIIA'' gene that codes for the insect control protein ''[[Bacillus thuringiensis]] var. [[Tenebrioninae|Tenebrionis]]'' is the method that was used.<ref name=":6" /> Prior to its insertion, research showed that [[Wild type|wild-type]] ''cryIIIA'' genes were expressed in low levels in plants.<ref name=":6" /> Plants with this gene expressed the ''cryIIIA'' protein at levels less than 0.001% of total leaf protein.<ref name=":6" /> Plants contain some resistance and toxicity to the Colorado potato beetles, but consistent protection requires higher levels of expression of the ''cryIIIA'' gene.<ref name=":6" /> Scientists modified ''cryIIIA'' by modifying the DNA protein-coding sequence without altering the [[amino acid]] sequence.<ref name=":6" /> The gene was transferred into the potato through a vector, specifically a ''[[Agrobacterium tumefaciens]]'' mediated transfer.<ref name=":6" /> 

Following the introduction of the gene, Russet Burbank potato plants with the gene were tested for kanamycin resistance and Colorado potato beetle resistance.<ref name=":6" /> In 308 plants that were tested, 18% (55) displayed complete resistance to the beetle.<ref name=":6" /> Later larval stages and adult beetles are more sensitive to ''cryIIIA'' protein.<ref name=":6" /> Controlling adults is important because they produce the next larvae generation. Colorado potato beetles overwinter as adults in the soil and feed immediately after emerging in the spring. In ''cryIIIA'' expression levels above 0.005%, adult feeding was negligible.<ref name=":6" /> Oviposition was also affected. In non-[[Transgene|transgenic]] leafs, mean number of eggs per cage were 117 and 143 in two separate trials.<ref name=":6" /> On the other hand, transgenic leafs displayed a mean of 1.7 and 0 eggs per cage in two trials.<ref name=":6" /> The female beetles were also studied, and the beetles put in the cage with transgenic plants displayed reduced size with ova that were partially or totally reabsorbed.<ref name=":6" /> They absorbed body fat and reproductive tissue as a result of ceasing consumption of transgenic plants.<ref name=":6" />

The potatoes showed benefits of the gene treatment; potatoes expressing the ''cryIIIA'' gene had protection from Colorado potato beetles in the laboratory and the field.<ref name=":6" /> Furthermore, these potato plants displayed agronomic and tuber characteristics that aligned with healthy Russet Burbank Potatoes.<ref name=":6" />

===Insecticidal management===
The large-scale use of insecticides in agricultural crops effectively controlled the pest until it became resistant to [[DDT]] in 1952 and [[dieldrin]] in 1958.<ref>{{cite journal |author1=Alyokhin, A. |author2=Baker, M. |author3=Mota-Sanchez, D. |author4=Dively, G. |author5=Grafius, E. |title=Colorado Potato Beetle Resistance to Insecticides |journal=American Journal of Potato Research |date=2008 |volume=85 |issue=6 |pages=395–413 |url=http://potatobeetle.org/AJPR_Review.html |doi=10.1007/s12230-008-9052-0|s2cid=41206911 |url-access=subscription }}</ref> [[Insecticide]]s remain the main method of pest control on commercial farms. However, many chemicals are often unsuccessful when used against this pest because of the beetle's ability to rapidly develop insecticide [[pesticide resistance|resistance]]. Different populations in different geographic regions have, between them, developed resistance to all major classes of insecticide,<ref name='JPotResearch'>{{cite journal |author1=Alyokhin, A. |author2=Baker, M. |author3=Mota-Sanchez, D. |author4=Dively, G. |author5=Grafius, E. |year=2008 |title=Colorado potato beetle resistance to insecticides |journal=American Journal of Potato Research |volume=85 |pages=395–413 |doi=10.1007/s12230-008-9052-0 |issue=6|s2cid=41206911 }}</ref><ref name=":5">{{cite journal |author=Hare, J. D. |date=1990 |title=Ecology and Management of the Colorado Potato Beetle |journal=Annual Review of Entomology |volume=35 |pages=81–100 |doi=10.1146/annurev.en.35.010190.000501 }}</ref> although not every population is resistant to every chemical.<ref name='JPotResearch' /> The species as a whole has evolved resistance to 56 different chemical insecticides.<ref>{{cite web |url=http://www.pesticideresistance.org/display.php?page=species&arId=141 |title=Leptinotarsa decemlineata |publisher=Arthropod Pesticide Resistance Database ([[Michigan State University]]) |access-date=2017-03-24}}</ref> The mechanisms used include improved metabolism of the chemicals, reduced sensitivity of target sites, less penetration and greater excretion of the pesticides, and some changes in the behavior of the beetles.<ref name='JPotResearch' />

{| class="wikitable" style="margin-left: auto; margin-right: auto; border: none;"
|+ Examples of insecticides available for the control of Colorado potato beetle on different crops in [[Kentucky]], USA.<ref name='Kentucky' />
! Insecticide class !! Common examples !! [[Potato]] !! [[Eggplant]] !! [[Tomato]] !! Notes
|-
! [[Organophosphate]]s
| [[phosmet]]
| X
| 
|
| on US Emergency Planning [[List of Extremely Hazardous Substances]]
|-
! 
| [[disulfoton]]
| X
|
| X
| Usage restricted by US government; manufacturer Bayer exited US market 2009
|-
! [[Carbamate]]s
| [[carbaryl]]
| X
| X
| X
| Widely used in US
|-
!
| [[carbofuran]]
| X
|
|
| One of the most toxic carbamates
|-
! [[Chlorinated hydrocarbon]]s
| [[methoxychlor]]
| X
|
| X
| Banned in EU 2002, in USA 2003
|-
! (Cycloldienes)
| [[endosulfan]]
| X
| X
| X
| Acutely toxic, bioaccumulates, [[endocrine disruptor]]. Global ban 2012 with exemptions until 2017
|-
! [[Insect growth regulator]]
| [[azadirachtin]]
| X
| X
| X
|
|-
! [[Spinosin]]
| [[spinosad]]
| 
| X
| X
|
|-
! [[Avermectin]]
| [[abamectin]]
| X
| 
| X
|
|-
|}

CPBs have [[Resistance (ecology)|evolved widespread insecticide resistance]].<ref name = "Kliot-Ghanim-2012" /> No cases without [[fitness cost]] or of negative cost are known.<ref name = "Kliot-Ghanim-2012" >
{{ Cite journal
    | year = 2012
    | publisher = [[John Wiley & Sons, Ltd.]]
    | issue = 11
    | volume = 68
    | last1 = Kliot
    | first1 = Adi
    | last2 = Ghanim
    | first2 = Murad
    | pages = 1431–1437
    | journal = [[Pest Management Science]]
    | title = Fitness costs associated with insecticide resistance
    | issn = 1526-498X
    | doi = 10.1002/ps.3395
 | pmid = 22945853
 | bibcode = 2012PMSci..68.1431K
 }}
</ref>

===Nonpesticidal management===
[[File:Bundesarchiv Bild 183-15032-0001, Vahldorf, Gesammelte Kartoffelkäfer.jpg|thumb|right|East German [[Ernst Thälmann Pioneer Organisation|Young Pioneers]] collecting beetles during the [[war against the potato beetle]]]]

[[Insecticide#Other biological approaches|Bacterial insecticides]] can be effective if application is targeted towards the vulnerable early-instar larvae. Two strains of the [[bacterium]] ''[[Bacillus thuringiensis]]'' produce toxins that kill the larvae.<ref name='TheInsects' /> Other forms of pest control, through [[non-pesticidal management|nonpesticidal management]] are available. Feeding can be inhibited by applying antifeedants, such as fungicides or products derived from Neem (''[[Azadirachta indica]]''), but these may have negative effects on the plants, as well.<ref name='TheInsects' /> The steam distillate of fresh leaves and flowers of [[tansy]] (''Tanacetum vulgare'') contains high levels of [[camphor]] and [[umbellulone]], and these chemicals are strongly repellent to ''L. decemlineata''.<ref>{{cite journal |author1=Schearer, W. R. |title=Components of Oil of Tansy (''Tanacetum vulgare'') that repel Colorado potato beetles (Leptinotarsa decemlineata) |journal=Journal of Natural Products |volume=47 |issue=6 |pages=964–969 |date=1984 |doi=10.1021/np50036a009|bibcode=1984JNAtP..47..964S }}</ref>

''[[Beauveria bassiana]]'' (Hyphomycetes) is a [[pathogen]]ic fungus that infects a wide range of insect species, including the Colorado potato beetle.<ref name="uconn">{{cite web|url=http://www.hort.uconn.edu/IPM/general/htms/bassiana.htm |title=University of Connecticut Extension |access-date=2017-05-23 |url-status=dead |archive-url=https://web.archive.org/web/20060901064449/http://www.hort.uconn.edu/ipm/general/htms/bassiana.htm |archive-date=2006-09-01}}</ref> It has shown to be particularly effective as a biological pesticide for ''L. decemlineata'' when used in combination with ''B. thuringiensis''.<ref>{{cite journal |author1=Wraight, S. P. |author2=Ramos, M. E. |title=Characterization of the synergistic interaction between Beauveria bassiana strain GHA and Bacillus thuringiensis morrisoni strain tenebrionis applied against Colorado potato beetle larvae |journal=[[Journal of Invertebrate Pathology]] |volume=144 |date=2017 |pages=47–57 |doi=10.1016/j.jip.2017.01.007|pmid=28108175 |doi-access=free |bibcode=2017JInvP.144...47W }}</ref>

Crop rotation is, however, the most important cultural control of ''L. decemlineata''.<ref name='Alyokhin' /> Rotation may delay the infestation of potatoes and can reduce the build-up of early-season beetle populations because the adults emerging from [[diapause]] can only disperse to new food sources by walking.<ref name='TheInsects' /> One 1984 study showed that rotating potatoes with nonhost plants reduced the density of early-season adults by 95.8%.<ref>{{cite journal |author1=Wright, R. J. |date=1984 |title=Evaluation of crop rotation for control of Colorado potato beetle (Coleoptera: Chrysomelidae) in commercial potato fields on Long Island |journal=Journal of Economic Entomology |volume=77 |issue=5 |pages= 1254–1259 |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1103&context=entomologyfacpub |doi=10.1093/jee/77.5.1254|url-access=subscription }}</ref>

Other cultural controls may be used in combination with crop rotation: [[Mulch]]ing the potato crop with straw early in the growing season may reduce the beetle's ability to locate potato fields, and the mulch creates an environment that favours beetle's predators; Plastic-lined trenches have been used as [[pitfall trap]]s to catch the beetles as they move toward a field of potatoes in the spring, exploiting their inability to fly immediately after emergence; [[flamethrower]]s may also be used to kill the beetles when they are visible at the top of the plant's foliage.<ref name='Vern'>{{cite web |url=https://www.uvm.edu/vtvegandberry/factsheets/potatobeetle.html |author1=Grubinger, V. |title=Colorado Potato Beetle |publisher=[[The University of Vermont]] |date=2004 |access-date=2017-07-20}}</ref>

=== Biological management ===
Some potential sources of control for the Colorado golden beetle is the [[Eulophidae|eulophid]] egg parasitoid ''Edovum puttleri''. This parasitoid can kill more than 80% of beetle eggs.<ref name="Hare 81–100">{{Cite journal |last=Hare |first=J D |date=January 1990 |title=Ecology and Management of the Colorado Potato Beetle |url=https://www.annualreviews.org/doi/10.1146/annurev.en.35.010190.000501 |journal=Annual Review of Entomology |language=en |volume=35 |issue=1 |pages=81–100 |doi=10.1146/annurev.en.35.010190.000501 |issn=0066-4170|url-access=subscription }}</ref> It does it by parasitization, probing, and host feeding. ''Edovum'' specializes in the Colorado potato beetle, which gives it easier access to the eggs it eats. This parasitoid tolerates warmer temperatures than the beetle.<ref name="Hare 81–100"/> The adults hunt during the warmest part of the day and have different food sources. The young feast on beetle eggs.<ref name=":5" /> Furthermore, these parasitoids do not overwinter which means using them for biological control requires raising them in insectaries and periodic releases. However, there are studies that attempt to genetically improve ''Edovum's'' tolerance to colder temperatures along with cultural manipulations that enable ''Edovum'' to provide useful, economic biological control.<ref name=":5" />

Another enemy/potential control method is a fungal pathogen called ''[[Beauveria bassiana|Beuveria bassiana]]''.<ref name=":5" /> This fungus has implications in population control of the beetles. It cannot be used to quickly contain large populations of beetles. Additionally, the pre-existing use of fungicide in disease management of crops presents an obstacle for the effectiveness of the fungus.<ref name=":5" /> Other reasons as to why this fungal treatment has not been utilized heavily include costs of production and longevity of formulations.<ref name=":5" />

===Spatial and temporal field management===
Colorado Potato beetles have also shown a capacity for spatial and temporal within-field management. In one study, populations of immigrating Colorado Potato beetles were systematically targeted and their established perimeter was measured over a large field.<ref name=":new1">{{cite journal |last1=Blom |first1=Paul |title=Spatial and Temporal Dynamics of Colorado Potato Beetle (Coleoptera: Chrysomelidae) in Fields with Perimeter and Spatially Targeted Insecticides |journal=Environmental Entomology |date=February 2002 |volume=31 |issue=1 |pages=149–159 |doi=10.1603/0046-225X-31.1.149 |doi-access=free }}</ref> Researchers found that immigrating adult beetles had almost no spatial dependence in any covariance-based treatment, while larval immigrant populations developed the highest densities in field centers. Results imply that perimeter tactics employed by Colorado Potato beetles can give valuable insight into site-specific resistance management programs to optimize insecticide usage.<ref name=":new1" /> However, researchers are still not confident about the long-term effects of such resistance management programs as yield reduction requires further studying.

==Relationship with humans==
===Cold War villain===
{{main|War against the potato beetle}}

During the [[Cold War]],  some countries in the [[Warsaw Pact]] claimed that the beetles had been introduced by the [[Central Intelligence Agency|CIA]] in an attempt to reduce food security by destroying the agriculture of the [[Soviet Union]].<ref name=colUWP>{{cite news |author=Sindelar, D. |title=What's Orange and Black and Bugging Ukraine? |url=http://www.rferl.org/content/ukraine-colorado-beetle-separatists/25365793.html |work=Radio Free Europe / Radio Liberty|date=29 April 2014 |access-date=18 May 2014}}<br>[https://www.nytimes.com/2014/05/05/world/europe/kievs-reins-weaken-as-chaos-spreads.html Ukraine's Reins Weaken as Chaos Spreads], [[The New York Times]] (4 May 2014)<br>{{in lang|uk}} [http://www.pravda.com.ua/news/2014/06/18/7029494/ Lyashko in Lviv poured green], [[Ukrayinska Pravda]] (18 June 2014)</ref> A widespread campaign was launched against the beetles; posters were put up and school children were mobilized to gather the pests and kill them in [[gasoline|benzene]] or [[distilled beverage|spirit]].<ref name=colUWP/>

===Philately===
[[File:Krumplibogár szobor02 - Hédervár.JPG|thumb|Statue of the Colorado potato beetle in [[Hédervár]], Hungary: It marks the discovery of the beetle at the site in 1947 during the rapid spread of the pest in Europe throughout the 20th century.<ref>{{cite journal |url=http://actazool.nhmus.hu/48Suppl1/saringer.pdf |author1=Saringer, G. |year=2002 |title=The Years Spent by Tibor Jermy Academician in Keszthely |journal=Acta Zoologica Academiae Scientiarum Hungaricae |volume=48 |pages=33–42}}</ref>]]

''L. decemlineata'' is an iconic species and has been used as an [[Philately|image on stamps]] because of its association with the recent history of both North America and Europe. For example, in 1956, Romania issued a set of four stamps calling attention to the campaign against insect pests,<ref>{{cite web |url=http://colnect.com/en/stamps/stamp/200057-Colorado_Potato_Beetle_Leptinotarsa_decemlineata-Campaign_against_insect_pests-Romania |title=Stamp catalog : Stamp › Colorado Potato Beetle (Leptinotarsa decemlineata) |date=2003–2017 |access-date=2017-05-23}}</ref> and it was featured on a 1967 stamp issued in [[Austria]].<ref>{{cite web |url=http://www.bugsonstamps.com/austria/austria_02_potato_beetle_796.htm |title=Skaps' bug stamps - Austria|author=Skaptason, J. L. |date=2000-10-28 |access-date=2017-05-23 |archive-url=https://web.archive.org/web/20140418094504/http://www.bugsonstamps.com/austria/austria_02_potato_beetle_796.htm |archive-date=2014-04-18}}</ref> The beetle also appeared on stamps issued in Benin, Tanzania, the United Arab Emirates, and Mozambique.<ref>{{cite web |url=http://www.potatobeetle.org/memorabilia.html |title=Potatobeetle.org Memorabilia |date=2008 |access-date=2017-05-23}}</ref>

===In popular culture===
Neapolitan [[mandolin]]s (also called Italian mandolins) are often called ''tater bugs'',<ref>{{cite book |author1=Greg Horne |date=2005|title=Beginning Mandolin |publisher=Alfred Music Publishing |isbn=978-0-739037-32-4|page=6}}</ref><ref>{{cite book |author1=Don Julin|author2=Scott Tichenor |date=2012|title=Mandolin For Dummies |publisher=John Wiley & Sons |isbn=978-1-119942-76-4|page=282}}</ref> a nickname given by American [[luthier]] [[Orville Gibson]], because the shape and stripes of the different color wood strips resemble the back of the Colorado beetle.<ref>{{cite book |author1=Fred Sokolow |author-link=Fred Sokolow |date=2014|title=101 Mandolin Tips |publisher=Hal Leonard Corporation |isbn=978-1-495009-03-7}}</ref>

The fans of [[Alemannia Aachen]] carry the nickname "Kartoffelkäfer", from the German name for the Colorado beetle, because of striped yellow-black jerseys of the team.<ref>{{cite news|url=https://www.dw.com/de/kartoffelk%C3%A4fer-sind-die-beste-werbung/a-1462104 |title="Kartoffelkäfer" sind die beste Werbung|author1=Marco Stoffel |date= 15 February 2005 |publisher=Deutsche Welle |access-date=2020-07-12}}</ref><ref>{{cite news |url=https://www.diekartoffelkaefer.de/ueber-uns/ |title=Warum "DieKartoffelkaefer.de" ? |access-date=2020-07-12 |archive-date=2022-01-24 |archive-url=https://web.archive.org/web/20220124201944/https://www.diekartoffelkaefer.de/ueber-uns/ |url-status=dead }}</ref>

During the [[2014 pro-Russian unrest in Ukraine]], the word {{transliteration|uk|kolorady}}, from the Ukrainian and Russian term for Colorado beetle ({{langx|uk|жук колорадський}}, {{langx|ru|колорадский жук}}), gained popularity among Ukrainians as a derogatory term to describe pro-Russian separatists in the [[Donetsk Oblast|Donetsk]] and [[Luhansk Oblast|Luhansk]] Oblasts (provinces) of [[Eastern Ukraine]]. The nickname reflects the similarity of black and orange stripes on [[Ribbon of Saint George|St. George's ribbons]] worn by many of the separatists.<ref>{{cite news|url=https://www.nytimes.com/2014/05/05/world/europe/kievs-reins-weaken-as-chaos-spreads.html |title=Ukraine's Reins Weaken as Chaos Spreads |author1=Kramermay, A. E. |date= 4 May 2014 |work=New York Times |access-date=2020-07-12}}</ref>

In some European cultures, the Colorado potato beetle is known as the '[[gourd]] beetle' due to the likeness of the beetle to various gourds of the [[Cucurbitaceae]] family.

==Notes==
:1.{{Note|Note1}}For a more comprehensive list of natural predators, pathogens and parasitoids, see [http://www.cabi.org/isc/datasheet/30380 here].

==References==
{{Reflist|30em}}

==External links==
{{Wikispecies|Leptinotarsa decemlineata|Colorado potato beetle}}
{{Commons|2=''Leptinotarsa decemlineata''}}
{{Collier's poster|Colorado Beetle}}
*[http://www.potatobeetle.org PotatoBeetle.org]
*[https://www.youtube.com/watch?v=0CYKU9jmBK0 Polish Film Chronicle: Fight against Colorado Beetle {{in lang|pl}}]

{{Coleoptera}}
{{Insects in culture}}

{{Taxonbar|from=Q156954}}
{{Authority control}}

[[Category:Chrysomelinae]]
[[Category:Potatoes]]
[[Category:Agricultural pest insects]]
[[Category:Beetles of the United States]]
[[Category:Fauna of the Western United States]]
[[Category:Beetles described in 1824]]
[[Category:Articles containing video clips]]
[[Category:Taxa named by Thomas Say]]
[[Category:Insects in culture]]
[[Category:Beetles of Europe]]
[[Category:Biological anti-agriculture weapons]]