''Epicauta vittata'' is a species of

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

in the family Meloidae, the blister beetles. It is native to eastern North America, including eastern

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and the eastern

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

.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 (: thoraces or thoraxes) or chest is a part of the anatomy of 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 di ...

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 (; ; : elytra, ) 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 ...

. 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 (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

, 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 (; : 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 life cycle, the stages th ...

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 amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grassh ...

. 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 distribution, cosmopolitan group of more than 50 species which make up the genus of annual plant, annual or short-lived perennial plants collectively known as amaranths. Some names include "prostrate pigweed" an ...

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

bean A bean is the seed of some plants in the legume family (Fabaceae) used as a vegetable for human consumption or animal feed. The seeds are often preserved through drying (a ''pulse''), but fresh beans are also sold. Dried beans are traditi ...

beet The beetroot (British English) or beet (North American English) is the taproot portion of a '' Beta vulgaris'' subsp. ''vulgaris'' plant in the Conditiva Group. The plant is a root vegetable also known as the table beet, garden beet, dinner ...

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

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.& ...

corn Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout Poaceae, grass that produces cereal grain. It was domesticated by indigenous peoples of Mexico, indigenous peoples in southern Mexico about 9,000 years ago ...

eggplant Eggplant (American English, US, Canadian English, CA, Australian English, AU, Philippine English, PH), aubergine (British English, UK, Hiberno English, IE, New Zealand English, NZ), brinjal (Indian English, IN, Singapore English, SG, Malays ...

, pea,

potato The potato () is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant ''Solanum tuberosum'', a perennial in the nightshade famil ...

, radish,

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

, squash,

sweet potato The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledonous plant in the morning glory family, Convolvulaceae. Its sizeable, starchy, sweet-tasting tuberous roots are used as a root vegetable, which is a staple food in parts of ...

tomato The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible Berry (botany), berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originate ...

, turnip,

clover Clovers, also called trefoils, are plants of the genus ''Trifolium'' (), consisting of about 300 species of flowering plants in the legume family Fabaceae originating in Europe. The genus has a cosmopolitan distribution with the highest diversit ...

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. Soy is a staple crop, the world's most grown legume, and an important animal feed. Soy is a key source o ...

, and

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial plant, 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, ...

. 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 * Disease vector, an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematics a ...

of the bean pod mottle virus, a plant pathogen. 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, a toxic

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

. This compound is a

vesicant A blister agent (or vesicant) is a chemical compound that causes severe skin, eye and mucosal pain and irritation in the form of severe chemical burns resulting in fluid filled blisters. Named for their ability to cause vesication, blister a ...

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 ...

ing of skin and mucous membranes. It is injurious to

livestock Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...

that consume beetles living in hay, and has been known to cause fatalities, particularly of

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...

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 th ...

, 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 ...

of the mouth, pawing, stretching,

diarrhea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

containing bits of intestinal mucosa, hypocalcaemia, and hypomagnesemia.

Cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

and

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal 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 d ...

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 is found across western and central North America and is a Bird migration, full migrant, breeding in Canada and the United States with resident ...

, eastern bluebird, and scissor-tailed flycatcher. Its eggs are attacked by another blister beetle, '' Epicauta atrata''.

Frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

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 fluid, serous and muc ...

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 () are the muscular hindlimbs of frogs that are consumed as food by humans in some cuisines. Frog legs are rich in protein, omega-3 fatty acids, vitamin A, and potassium. They are often said to taste like chicken because of the mild fl ...

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

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

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