Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes


TaxonomyBrowse
Info
ImagesLinksBooksData

Family Meloidae - Blister Beetles

Meloe sp. - Meloe - female Unknown Beetle - Lytta aenea Large Black & Yellow Beetle - Epicauta atrivittata Beetle - Lytta aenea Blister Beetle - Epicauta murina - male Blister Beetle - Epicauta murina Epicauta? - Epicauta Oil Beetle - Meloe impressus
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
Superfamily Tenebrionoidea (Fungus, Bark, Darkling and Blister Beetles)
Family Meloidae (Blister Beetles)
Explanation of Names
Meloidae Gyllenhaal 1810
the name "blister beetles" refers to the ability of causing skin blisters if handled
Numbers
ca. 410 spp. in 22 genera of 3 subfamilies in our area, ~3000 spp. in 120 genera of 4 subfamilies worldwide(1)(2)
Overview of our fauna
Family Meloidae
Subfamily Meloinae
Tribe Lyttini Lytta
Tribe Meloini Meloe
Incertae sedis Spastonyx
Subfamily Nemognathinae
Size
3-70 mm(3), typically 10-20 mm
Identification
Medium to large beetles, typically elongated and rather cylindrical, often found on flowers, foliage.
Head broad, generally rectangular when viewed from above.
Pronotum cylindrical and narrower than both the head and base of elytra.
Elytra not flat, typically rolled over abdomen.
Body soft, somewhat leathery.
Antennae filiform (thread-like) or moniliform (beaded).
Tarsi 5-5-4; claw either toothed or lobed.
Blister beetles of e. US are generally dull in color; western ones often very colorful(4), apparently aposematic.
Key to New World genera in(5)
Short-winged forms
Range
worldwide and across NA, with greatest diversity in arid/semiarid areas (sw. US)(1)
Food
For larval food, most utilize the provisions and larvae of native ground nesting bees (esp. Megachilidae & Andrenidae); several genera (in our area, Epicauta & Linsleya) utilize grasshopper eggs (Acridoidea)(3). Adults feed on leaves and flowers of several families of plants, particularly Asteraceae, Fabaceae, and Solanaceae(1)
Life Cycle
Life cycle is hypermetamorphic. Larvae are parasitoids. Eggs are laid in batches in soil near nests of hosts, sometimes in nest of bee host, or on stems, foliage, or flowers. Larvae undergo hypermetamorphosis--first instar larvae (usually called triungulins) are active, have well-developed legs and antennae. These typically search for hosts. Later instars tend to have reduced legs and be less active, having found hosts. There is a coarctate (pseudopupal) stage, which is usually how the larvae overwinter. Life cycle may be as short as 30 days, or as long as three years. It is typically one year, corresponding to that of host(1)(4)(6).
Triungulins of some meloids, e.g. in Meloe, aggregate and attract male bees with chemical signals (Saul-Gershenz & Millar 2006).
Remarks
Pressing, rubbing, or squashing blister beetles may cause them to exude hemolymph which contains the blistering compound cantharidin. Ingestion of blister beetles can be fatal. Eating blister beetles with hay may kill livestock. Cantharidin is commercially known as Spanish Fly.
Males of some other beetles (notably, Pedilus and some Anthicidae) seek out blister beetles, climb onto them and lick off the exuded cantharidin. These other beetles, resistant to the toxic effects, use the agent to impress their females; the cantharidin is transferred to the female with the sperm packet during mating. The eggs the female lays are coated with cantharidin to protect them from predators. Some plant bugs (e.g. Aoplonema) are also attracted to meloid beetles. (based on Jim McClarin's comment)
See Also
In similar families, head is usually not wider than pronotum(4): Cantharidae have elytra flat, not rolled · Oedemeridae have no "neck" · Pyrochroidae have antennae serrate (saw-like) or pectinate (comb-like)
Internet References
Overview of FL fauna (Selander & Fasulo)(7)
image gallery & info on world fauna in(8)
Works Cited
1.American Beetles, Volume II: Polyphaga: Scarabaeoidea through Curculionoidea
Arnett, R.H., Jr., M. C. Thomas, P. E. Skelley and J. H. Frank. (eds.). 2002. CRC Press LLC, Boca Raton, FL.
2.Order Coleoptera Linnaeus, 1758. In: Zhang Z.-Q. (ed.) Animal biodiversity: An outline of higher-level classification...
Slipinski S.A., Leschen R.A.B., Lawrence J.F. 2011. Zootaxa 3148: 203–208.
3.Blister beetles (Coleoptera: Meloidae) of Wisconsin: distribution and ecology
Marschalek D.A. 2013. University of Wisconsin - Madison. PhD dissertation. viii+349 pp.
4.Peterson Field Guides: Beetles
Richard E. White. 1983. Houghton Mifflin Company.
5.The New World genera of Meloidae (Coleoptera): a key and synopsis
Pinto J.D., Bologna M.A. 1999. J. Nat. Hist. 33: 569-620.
6.Introduction to North American Beetles
Charles S. Papp. 1984. Entomography Pubns.
7.U. of Florida and Dep. of Agriculture Website
8.Meloidae.com