''Epicauta vittata'' is a species of

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

in the family

Meloidae Blister beetles are beetles of the family Meloidae, so called for their defensive secretion of a blistering agent, cantharidin. About 7,500 species are known worldwide. Many are conspicuous and some are aposematically colored, announcing their ...

, the blister beetles. It is native to eastern North America, including eastern Canada and the eastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

.Selander, R. B. and T. R. Fasulo
Blister beetles.
EENY-166. University of Florida IFAS. Published 2000, revised 2010. It is known commonly as the striped blister beetle and the old-fashioned potato beetle. It is known as an agricultural pest.

Description

The adult beetle is 9 to 17 millimeters long. It is long and slender, with a hairy, punctate body. The

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...

is narrower than the head and abdomen. It is black and yellow, its color pattern varying across its geographical range. It has two black spots on the head, two black stripes on the thorax, and two or three black stripes on each

elytron An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...

. Beetles from northern populations have two elytral stripes, and southern beetles have three.Capinera, J. L
Striped Blister Beetle, ''Epicauta vittata'' (Fabricius) (Coleoptera: Meloidae).
EENY-280. Entomology and Nematology. Florida Cooperative Extension Service. University of Florida IFAS. 2003. The

larva A larva (; plural larvae ) 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. Th ...

, which is a triungulin, changes in appearance as it develops. The new larva is whitish and has long legs that allow it to be mobile. During this more mobile stage, it parasitizes a grasshopper egg case. From there, it becomes a sedentary grub. When it becomes a sedentary grub it darkens to a reddish-brown color with darker bands, and the legs shrink.

Life cycle

Many blister beetles have a complex developmental cycle in which the larva and

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

experience drastic changes in morphology between growth phases. There are one or two generations per year, with peak abundance of adults in the summer, or slightly earlier in more hospitable climate types. The adult female produces eggs about every 10 days. It deposits them in masses of 100 to 200 in a tubular chamber a few centimeters deep in the soil, then covers them. The eggs are whitish and about 2 millimeters long. They hatch within 16 days. The functional legs of the new larva allow it to seek its food, the egg of a

grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grasshoppe ...

. As it feeds and develops at its food source, its legs become reduced. The striped blister beetle is associated with grasshopper species that produce large egg-pods, such as the two-striped grasshopper (''Melanoplus bivittatus'') and differential grasshopper (''Melanoplus differentialis'').

Impacts

The adult beetle is most active during the morning and late afternoon hours, when it feeds on plants. During the heat of mid-day it seeks shelter, and in hot, dry climates it may only be active in the evening. Its preferred host plants are anything solanaceous, and other plants including

amaranth ''Amaranthus'' is a cosmopolitan genus of annual or short-lived perennial plants collectively known as amaranths. Some amaranth species are cultivated as leaf vegetables, pseudocereals, and ornamental plants. Catkin-like cymes of densely pack ...

s (genus ''Amaranthus''). It also feeds on a variety of crop plants, including

bean A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes thr ...

beet The beetroot is the taproot portion of a beet plant, usually known in North America as beets while the vegetable is referred to as beetroot in British English, and also known as the table beet, garden beet, red beet, dinner beet or golden beet ...

carrot The carrot (''Daucus carota'' subsp. ''sativus'') is a root vegetable, typically orange in color, though purple, black, red, white, and yellow cultivars exist, all of which are domesticated forms of the wild carrot, ''Daucus carota'', nati ...

cabbage Cabbage, comprising several cultivars of ''Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage ( ''B.&nbs ...

corn Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...

eggplant Eggplant ( US, Canada), aubergine ( UK, Ireland) or brinjal (Indian subcontinent, Singapore, Malaysia, South Africa) is a plant species in the nightshade family Solanaceae. ''Solanum melongena'' is grown worldwide for its edible fruit. Mo ...

pea The pea is most commonly the small spherical seed or the seed-pod of the flowering plant species ''Pisum sativum''. Each pod contains several peas, which can be green or yellow. Botanically, pea pods are fruit, since they contain seeds and d ...

potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern United S ...

radish The radish (''Raphanus raphanistrum'' subsp. ''sativus'') is an edible root vegetable of the family Brassicaceae that was domesticated in Asia prior to Roman times. Radishes are grown and consumed throughout the world, being mostly eaten raw a ...

spinach Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either fr ...

squash Squash may refer to: Sports * Squash (sport), the high-speed racquet sport also known as squash racquets * Squash (professional wrestling), an extremely one-sided match in professional wrestling * Squash tennis, a game similar to squash but pla ...

sweet potato The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledonous plant that belongs to the bindweed or morning glory family, Convolvulaceae. Its large, starchy, sweet-tasting tuberous roots are used as a root vegetable. The young shoot ...

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

turnip The turnip or white turnip (''Brassica rapa'' subsp. ''rapa'') is a root vegetable commonly grown in temperate climates worldwide for its white, fleshy taproot. The word ''turnip'' is a compound of ''turn'' as in turned/rounded on a lathe and ...

clover Clover or trefoil are common names for plants of the genus ''Trifolium'' (from Latin ''tres'' 'three' + ''folium'' 'leaf'), consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus h ...

soybean The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses. Traditional unfermented food uses of soybeans include soy milk, from which tofu an ...

, and

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as we ...

. It is considered to be one of the most problematic of the pest blister beetles in its range. It feeds voraciously, prefers crop plants, damages fruits, and forms swarms that travel ''en masse''. It may be a

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

of the

bean pod mottle virus ''Bean pod mottle virus'', or BPMV, is a species of plant pathogenic virus in the family ''Secoviridae''. It is known to infect soybean crops. Description BPMV is the viral pathogen that causes the disease Bean Pod Mottle in soybeans and other ...

, a

plant pathogen Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomy ...

. Worse than its damage to plants is its toxicity.Bailey, W. C., et al
G4569 Blister Beetle Management in Alfalfa.
University of Missouri Extension. 1993. Like other blister beetles, it contains

cantharidin Cantharidin is an odorless, colorless fatty substance of the terpenoid class, which is secreted by many species of blister beetles. It is a burn agent or a poison in large doses, but preparations containing it were historically used as aphrodisiac ...

, a toxic

terpenoid The terpenoids, also known as isoprenoids, are a class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeably with "terpenes", ...

. This compound is a

vesicant A blister agent (or vesicant), is a chemical compound that causes severe skin, eye and mucosal pain and irritation. They are named for their ability to cause severe chemical burns, resulting in painful water blisters on the bodies of those affec ...

that causes the

blister A blister is a small pocket of body fluid (lymph, serum, plasma, blood, or pus) within the upper layers of the skin, usually caused by forceful rubbing (friction), burning, freezing, chemical exposure or infection. Most blisters are filled w ...

ing of skin and mucous membranes. It is injurious to

livestock Livestock are the Domestication, domesticated animals raised in an agriculture, agricultural setting to provide labor and produce diversified products for consumption such as meat, egg as food, eggs, milk, fur, leather, and wool. The term is som ...

that consume beetles living in

hay Hay is grass, legumes, or other herbaceous plants that have been cut and dried to be stored for use as animal fodder, either for large grazing animals raised as livestock, such as cattle, horses, goats, and sheep, or for smaller domesticated ...

, and has been known to cause fatalities, particularly of

horse The horse (''Equus ferus caballus'') is a Domestication, domesticated, odd-toed ungulate, one-toed, ungulate, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two Extant taxon, extant subspecies of wild horse, ''Equus fer ...

s. Cantharidin toxicity in an animal may be called cantharidiasis. The cantharidin content of one striped blister beetle has been reported to be about 0.31 to 1.45 milligrams in one small sample,Eisner, T., et al. (1990)
Systemic retention of ingested cantharidin by frogs.
''Chemoecology'' 1(2), 57–62. and about 4DiFonzo, C
Cantharidin content and lethal dose of common Michigan blister beetles.
Field Crops Entomology, Michigan State University. 2009. or 5 milligrams in general. The toxic dose of cantharidin in horses is about one milligram per kilogram body weight, and the ingestion of 30 to 50 beetles can be fatal. Even two to five beetles can cause

horse colic Colic in horses is defined as abdominal pain, but it is a clinical symptom rather than a diagnosis. The term colic can encompass all forms of gastrointestinal conditions which cause pain as well as other causes of abdominal pain not involving the g ...

, and hay containing the remnants or fluids of crushed beetles can cause symptoms when eaten. Signs of toxicity include blisters and

ulcers An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing o ...

of the mouth, pawing, stretching,

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

containing bits of intestinal mucosa,

hypocalcaemia Hypocalcemia is a medical condition characterized by low calcium levels in the blood serum. The normal range of blood calcium is typically between 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L) while levels less than 2.1 mmol ...

, and

hypomagnesemia Magnesium deficiency is an electrolyte disturbance in which there is a low level of magnesium in the body. It can result in multiple symptoms. Symptoms include tremor, poor coordination, muscle spasms, loss of appetite, personality changes, and ...

Cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

and

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus ''Ovis'', in everyday usage it almost always refers to domesticated sh ...

appear to be less susceptible but can suffer some symptoms from beetle ingestion.

Ecology

Predators of the striped blister beetle include robber flies and several birds, such as the

western meadowlark The western meadowlark (''Sturnella neglecta'') is a medium-sized icterid bird, about in length. It nests on the ground in open grasslands across western and central North America. It feeds mostly on bugs, but will also feed on seeds and berrie ...

eastern bluebird The eastern bluebird (''Sialia sialis'') is a small North American migratory thrush found in open woodlands, farmlands, and orchards. The bright-blue breeding plumage of the male, easily observed on a wire or open perch, makes this species a ...

, and

scissor-tailed flycatcher The scissor-tailed flycatcher (''Tyrannus forficatus''), also known as the Texas bird-of-paradise and swallow-tailed flycatcher, is a long-tailed bird of the genus ''Tyrannus'', whose members are collectively referred to as kingbirds. The kingbi ...

. Its eggs are attacked by another blister beetle, '' Epicauta atrata''.

Frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

s are apparently not affected by Meloidae beetle toxin, and "consume meloids with impunity". After eating blister beetles, frogs retain the toxin in their tissues and secrete it in their

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is ...

for a short time, and predators that consume the frogs can be poisoned. This includes humans who consume foods such as

frog legs Frog legs ( French: ''Cuisses de grenouille'') are one of the better-known delicacies of French cuisine, where it has been considered as a national delicacy. The legs of edible frogs are also consumed in other parts of the world, including Vi ...

Northern leopard frog ''Lithobates pipiens''Integrated Taxonomic Information System nternet2012''Lithobates pipiens'' pdated 2012 Sept; cited 2012 Dec 26Available from: www.itis.gov/ or ''Rana pipiens'', commonly known as the northern leopard frog, is a species ...

s fed striped blister beetles in studies accumulated cantharidin in their thigh muscles, among other tissues. It is estimated that as little as 200 grams of frog legs from beetle-fed frogs could contain a potentially fatal dose of toxin.

References

External links

{{Taxonbar, from=Q937565 Agricultural pest insects Meloidae Beetles of North America Beetles described in 1775 Taxa named by Johan Christian Fabricius