Colorado potato beetle
Encyclopedia
The Colorado potato beetle (Leptinotarsa decemlineata), also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle or the potato bug, is an important pest of potato
crops. It is approximately 10 mm (0.4 inch) long, with a bright yellow/orange body and five bold brown stripes along the length of each of its elytra
. It can easily be confused with its close cousin and look-alike, the false potato beetle
.
from specimens collected in the Rocky Mountains
on buffalo-bur, Solanum rostratum
. The origin of the beetle is somewhat unclear, but it seems that Colorado
and Mexico
are a part of its native distribution in southwestern North America. In about 1840, the species adopted the cultivated potato into its host range and it rapidly became a most destructive pest of potato crops. The large scale use of insecticides in agricultural crops effectively controlled the pest until it became resistant to DDT
in the 1950s. Other pesticides have since been used but the insect has, over time, developed resistance to them all.
Colorado potato beetle females are very prolific; they can lay as many as 800 eggs. The eggs are yellow to orange, and are about 1.5 mm long. They are usually deposited in batches of about 30 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 on either side. They feed on the leaves. Larvae progress through four distinct growth stages (instars). First instars are about 1.5 mm long; the fourth is about 8 mm long. The larvae in the accompanying picture are third instars. The first through third instars each last about 2–3 days; the fourth, 4–7 days. Upon reaching full size, each fourth instar spends an additional several days as a non-feeding 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 pupate. Depending on temperature, light-regime and host quality, the adults may emerge in a few weeks to continue the life cycle, or enter diapause and delay emergence until spring. They then return to their host plant to mate and feed. In some locations, three or more generations may occur each growing season.
s are currently the main method of beetle 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 resistance
. The Colorado potato beetle has developed resistance to all major insecticide classes, although not every population is resistant to every chemical. In the United Kingdom
, where the Colorado beetle is a rare visitor on imported farm produce, it is a notifiable pest: any found must be reported to DEFRA.
High fecundity usually allows Colorado potato beetle populations to withstand natural enemy pressure. Still, in the absence of insecticides natural enemies can sometimes reach densities capable of reducing Colorado potato beetle numbers below economically damaging levels. A ground beetle, Lebia grandis
is a predator of the eggs and larvae and its larvae are parasitoid
s of the Colorado beetle's pupae. Beauveria bassiana
(Hyphomycetes) is a pathogenic fungus that infects a wide range of insect species, including the Colorado potato beetle. It is probably the most widely used natural enemy of the Colorado potato beetle, with readily available commercial formulations that can be applied using a regular pesticide sprayer.
In 1877, the Colorado beetle reached Germany where it was eradicated. During or immediately following WWI, it became established near USA military bases in Bordeaux and proceeded to spread by the beginning of WWII to Belgium, the Netherlands and Spain. The population increased dramatically during and immediately following WWII 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 the EU it remains a regulated (quarantine) pest for the UK, Republic of Ireland, Balearic Islands, Cyprus, Malta and southern parts of Sweden and Finland. It is not endemic in any of these Member States, although occasional infestations occur, as in Finland in the summer of 2011, when strong winds blew from Russia, where the species is endemic.
n postal authority featured the beetle on a 1967 stamp. The beetle also appeared on stamps issued in Benin, Tanzania, the United Arab Emirates, and Mozambique.
The Belgian postal authority featured a drawing of the Colorado beetle and larvae on a 1934 and 1935 propaganda postcard.
Potato
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
crops. It is approximately 10 mm (0.4 inch) long, with a bright yellow/orange body and five bold brown stripes along the length of each of its elytra
Elytron
An elytron is a modified, hardened forewing of certain insect orders, notably beetles and a few of the true bugs ; in most true bugs, the forewings are instead called hemelytra, as only the basal half is thickened while the apex is membranous...
. It can easily be confused with its close cousin and look-alike, the false potato beetle
False potato beetle
The false potato beetle , Leptinotarsa juncta, is a beetle found primarily in the Mid-Atlantic and southeastern regions of the United States. Recently, it has also been discovered in the northeastern portion of Ohio as well...
.
History
The beetle was described in 1824 by Thomas SayThomas Say
Thomas Say was an American naturalist, entomologist, malacologist, herpetologist and carcinologist. A taxonomist, he is often considered to be the father of descriptive entomology in the United States. He described more than 1,000 new species of beetles and over 400 species of insects of other...
from specimens collected in the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
on buffalo-bur, Solanum rostratum
Solanum rostratum
Solanum rostratum is a species of nightshade that is native to the United States and northern and central Mexico. Common names include buffalo bur, spiny nightshade, and Texas thistle....
. The origin of the beetle is somewhat unclear, but it seems that Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
are a part of its native distribution in southwestern North America. In about 1840, the species adopted the cultivated potato into its host range and it rapidly became a most destructive pest of potato crops. The large scale use of insecticides in agricultural crops effectively controlled the pest until it became resistant to DDT
DDT
DDT is one of the most well-known synthetic insecticides. It is a chemical with a long, unique, and controversial history....
in the 1950s. Other pesticides have since been used but the insect has, over time, developed resistance to them all.
Life cycle
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e with humped backs and two rows of dark brown spots on either side. They feed on the leaves. Larvae progress through four distinct growth stages (instars). First instars are about 1.5 mm long; the fourth is about 8 mm long. The larvae in the accompanying picture are third instars. The first through third instars each last about 2–3 days; the fourth, 4–7 days. Upon reaching full size, each fourth instar spends an additional several days as a non-feeding 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 pupate. Depending on temperature, light-regime and host quality, the adults may emerge in a few weeks to continue the life cycle, or enter diapause and delay emergence until spring. They then return to their host plant to mate and feed. In some locations, three or more generations may occur each growing season.
As a crop pest
Colorado beetles are a serious pest of potatoes. They may also cause significant damage to tomatoes and eggplants. Both adults and larvae feed on foliage and may skeletonize the crop. InsecticideInsecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
s are currently the main method of beetle 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 resistance
Pesticide resistance
Pesticide resistance is the adaptation of pest population targeted by a pesticide resulting in decreased susceptibility to that chemical. In other words, pests develop a resistance to a chemical through natural selection: the most resistant organisms are the ones to survive and pass on their...
. The Colorado potato beetle has developed resistance to all major insecticide classes, although not every population is resistant to every chemical. In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, where the Colorado beetle is a rare visitor on imported farm produce, it is a notifiable pest: any found must be reported to DEFRA.
High fecundity usually allows Colorado potato beetle populations to withstand natural enemy pressure. Still, in the absence of insecticides natural enemies can sometimes reach densities capable of reducing Colorado potato beetle numbers below economically damaging levels. A ground beetle, Lebia grandis
Lebia grandis
Lebia grandis is a ground beetle in the family Carabidae found in North America. It is a specialist predator on the eggs and larvae of Colorado potato beetles, and its larvae are obligate parasitoids of Colorado potato beetle pupae.-Description:...
is a predator of the eggs and larvae and its larvae are parasitoid
Parasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...
s of the Colorado beetle's pupae. Beauveria bassiana
Beauveria bassiana
Beauveria bassiana is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the entomopathogenic fungi. It is being used as a biological insecticide to control a number of pests such as...
(Hyphomycetes) is a pathogenic fungus that infects a wide range of insect species, including the Colorado potato beetle. It is probably the most widely used natural enemy of the Colorado potato beetle, with readily available commercial formulations that can be applied using a regular pesticide sprayer.
In Europe
In 1877, the Colorado beetle reached Germany where it was eradicated. During or immediately following WWI, it became established near USA military bases in Bordeaux and proceeded to spread by the beginning of WWII to Belgium, the Netherlands and Spain. The population increased dramatically during and immediately following WWII 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 the EU it remains a regulated (quarantine) pest for the UK, Republic of Ireland, Balearic Islands, Cyprus, Malta and southern parts of Sweden and Finland. It is not endemic in any of these Member States, although occasional infestations occur, as in Finland in the summer of 2011, when strong winds blew from Russia, where the species is endemic.
Philately
The AustriaAustria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
n postal authority featured the beetle on a 1967 stamp. The beetle also appeared on stamps issued in Benin, Tanzania, the United Arab Emirates, and Mozambique.
The Belgian postal authority featured a drawing of the Colorado beetle and larvae on a 1934 and 1935 propaganda postcard.
Media references
The beetle is featured prominently in the science-fiction/horror novel The Devil's Coach Horse (also known as The Black Horde) by Richard Lewis. In the novel a plague of an evolved and flesh hungry type of the beetle (as well as the titular creature) is unknowingly released in Great Britain and the United States.External links
- www.potatobeetle.org
- Insect Olfaction of Plant Odour: Colorado Potato Beetle and Aphid Studies
- Whalonlab link
- Colorado potato beetle threatens Dutch potatoes
- Polish Film Chronicle: Fight against Colorado Beetle (pl.)
- potato beetles, Leptinotarsa spp. on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
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