Meloe

Meloe is a genus of blister beetles commonly referred to as oil beetles. The name derives from their defensive strategy: when threatened by collectors or predators they release oily droplets of hemolymph from their joints (legs, neck, and antennae). This fluid is bright orange and contains cantharidin, a poisonous chemical compound. Wiping the chemical on skin can cause blistering and painful swelling of the skin. This defensive strategy is not exclusive to this genus; all meloids possess and exude cantharidin upon threat.
Morphology
Members of this genus typically have shortened elytra and lack functional wings. They are often iridescent blue, green, or black with pits/punctures on the elytra and thorax, and a bloated abdomen. Male antennae have kinks in some species which are shaped differently in different species.
Biology
As with all other members of Meloidae, the larval cycle is hypermetamorphic; the larva goes through several body types, the first of which is typically a mobile triungulin that finds and attaches to a host in order to gain access to the host's offspring. They usually climb onto a flower head, and await a bee there. They will then attach themselves to the bee. If it is a male, they wait for mating with a female. They will switch to the female when this takes place. If the bee is a female, however, she will take them back to her nest unwittingly. Once in the nest, the larvae morphs into a grub-like "couch potato" and feeds upon all of the provisions and the larva. Next, they form a pupa and emerge in various seasons depending on the species. Each species of Meloe may attack only a single species or genus of bees. Some are generalists. Though sometimes considered parasitoids, it appears that in general, the Meloe larva consumes the bee larva along with its provisions, and can often survive on the provisions alone; thus they do not truly qualify for this designation (see Parasitoid for definition).
Upon surfacing from their underground lives as larvae, the adults feed on plants in the Ranunculaceae, Ipomoaceae, and Solanaceae families. Meloe have appetites which are virtually insatiable.
Mating begins when a male mounts a female and releases chemical components through the kinks on the antennae, massaging her antennae and pulling them back. This serves to calm the female. Mating then occurs, with the male transferring his cantharidin to the female during this period and she coats her eggs with it.
Species
The following species are recognised in the genus Meloe:
Meloe aegyptius
Meloe aeneus
Meloe afer
Meloe affinis
Meloe ajax
Meloe aleuticus
Meloe algiricus
Meloe americanus
Meloe angusticollis – short-winged blister beetle
Meloe apenninicus
Meloe auriculatus
Meloe austrinus
Meloe autumnalis
Meloe baamarani
Meloe balteata
Meloe barbarus
Meloe baudii
Meloe bicolor
Meloe bitoricollis
Meloe brevicollis – short-necked oil beetle
Meloe californicus
Meloe campanicollis
Meloe cantharoides
Meloe carbonaceus
Meloe cavensis
Meloe chiliensis
Meloe chinensis Pan & Bologna, 2021
Meloe cicatricosus
Meloe cinnabarina
Meloe coarctatus
Meloe coecus
Meloe coelatus
Meloe corvinus
Meloe decemguttatus
Meloe decorus
Meloe dianella
Meloe distincticornis Pan & Bologna, 2021
Meloe dominicanus
Meloe dugesi
Meloe erythrocnemus
Meloe exiguus
Meloe fenestrata
Meloe fernandezi
Meloe flavicomus
Meloe formosensis
Meloe foveolatus
Meloe franciscanus
Meloe glazunovi
Meloe gomari
Meloe gracilicornis
Meloe himalayensis Pan & Bologna, 2021
Meloe hirsutus
Meloe hungarus
Meloe ibericus
Meloe impressus
Meloe kashmirensis Pan & Bologna, 2021
Meloe kaszabi Pan & Bologna, 2021
Meloe laevis – oil beetle
Meloe lateantennatus Pan & Bologna, 2021
Meloe luctuosus
Meloe lunata
Meloe mediterraneus - mediterranean oil beetle
Meloe menoko
Meloe nanus
Meloe nebulosus
Meloe niger
Meloe occultus
Meloe ocellata
Meloe oculatus
Meloe olivieri
Meloe orientalis Pan & Bologna, 2021
Meloe paropacus
Meloe podalirii
Meloe poggii Pan & Bologna, 2021
Meloe proscarabaeus Linnaeus, 1758 - black oil beetle
Meloe quadricollis
Meloe reitteri
Meloe rufiventris
Meloe rugosus - rugged oil beetle
Meloe sarmaticus
Meloe semenowi
Meloe shapovalovi Pan & Bologna, 2021
Meloe sibirica
Meloe spec
Meloe strigulosus
Meloe trifascis
Meloe tripunctatus
Meloe tropicus
Meloe tuccius
Meloe uralensis
Meloe ursus
Meloe vandykei
Meloe variegatus
Meloe violaceus - violet oil beetle
Meloe xuhaoi Pan & Bologna, 2021
Meloë fasciatus
Meloë flammeus
Treiodous barranci
BOLD:AAI1406 (Meloe sp.)
BOLD:ADP2858 (Meloe sp.)
BOLD:ADS0345 (Meloe sp.)
BOLD:AEB7065 (Meloe sp.)
BOLD:AEH9609 (Meloe sp.)
BOLD:AEI3522 (Meloe sp.)
BOLD:AEI4887 (Meloe sp.)
BOLD:AEI5774 (Meloe sp.)
BOLD:AEI5775 (Meloe sp.)
References
External links
Meloidae
Tenebrionoidea genera