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Genus Meloe - Oil Beetles

Meloe angusticollis - female Beetle larvae Phoresy? - Meloe blister beetles - Meloe dugesi Blister beetle with hitchhikers. - Meloe campanicollis - male Meloe - male Oil Beetle (Meloe sp.)? - Meloe Beelte - Meloe oil beetle - Meloe - male
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)
No Taxon (Series Cucujiformia)
Superfamily Tenebrionoidea (Fungus, Bark, Darkling and Blister Beetles)
Family Meloidae (Blister Beetles)
Subfamily Meloinae
Genus Meloe (Oil Beetles)
Synonyms and other taxonomic changes
Nearctic fauna revised in(1)
Explanation of Names
Meloe Linnaeus 1758
Origin obscure, may come from early medical literature (the term melloes appears in the writings of Paracelsus); the common name refers to the habit of exuding yellowish oily liquid from the joints when molested(2)
22 spp. in our area(3), >150 total, arranged into 16 subgenera(4)
12-30 mm(2)
Hind wings absent; elytra reduced and overlap at base.
Males smaller than females, with modified antennae:

Species not yet in guide:
M. afer Bland, 1864 [western]
M. aleuticus Borchmann, 1942 [AK]
M. exiguus Pinto & Selander, 1970 [midwestern]
M. nebulosus Pinto & Selander, 1970 [NM]
M. quadricollis Van Dyke, 1928 [CA]
M. vandykei Pinto & Selander, 1970 [western]
Primarily holarctic (mostly Palaearctic), with meager representation in more southern areas; throughout NA (to nw. Colombia; Hispaniola)(3)(4)
Ground or low foliage(2)
Larvae feed on eggs and other food in bees' nests(2)
Life Cycle
In some species, triungulins aggregate and use chemical signals to attract male bees to which they attach themselves. This allows transport (and transfer) to a female bee who carries them back to her nest (Saul-Gershenz & Millar 2006).
First-instar larvae climb to the top of a plant as a group, clump together in the shape of a female solitary ground bee, exude a scent imitating the female bee pheromone. When a male bee comes and tries to mate with the clump of larvae, some of these clamp onto his hairs and eventually get to female bees when he mates for real. Impregnated female bees fly off and build nests in burrows; triungulins move to the new nests and feed on honey and pollen stocked by the bee for her own young. --Jim McClarin's comment
In males of some species mid-antennal segments are modified, and the c-shaped ‘kinks’ involving antennomeres V–VII are used to grasp female antennae during pre-mating displays (Pinto & Mayor 1986)
Our only representative of the worldwide tribe Meloini Gyllenhal 1810, that contains 3 genera in the New World alone(4)
Print References
Bland R.G. (1986) Antennal and mouthpart sensilla of the blister beetle, Meloe campanicollis (Coleoptera: Meloidae). Great Lakes Entomologist 19(4): 209–215.
Pinto J., Mayor A. (1986) Size, mating success and courtship pattern in the Meloidae (Coleoptera). Ann. Ent. Soc. Am. 79: 597–604.
Saul-Gershenz L.S., Millar J.G. (2006) Phoretic nest parasites use sexual deception to obtain transport to their host's nest. PNAS 103: 14039-14044 (Abstract)
Works Cited
1.The bionomics of blister beetles of the genus Meloe and a classification of the New World species
Pinto J.D., Selander R.B. 1970. Ill. Biol. Monogr. 42:1-222.
2.Peterson Field Guides: Beetles
Richard E. White. 1983. Houghton Mifflin Company.
3.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.
4.The New World genera of Meloidae (Coleoptera): a key and synopsis
Pinto J.D., Bologna M.A. 1999. J. Nat. Hist. 33: 569-620.