Triungulin
Guides
Meloe angusticollis
short-winged blister beetle, oil beetle
Meloe angusticollis is a North American blister beetle known for its short elytra that leave most of the abdomen exposed. Adults release cantharidin-laden hemolymph as a chemical defense, which causes skin blistering in humans. The species exhibits hypermetamorphosis, with mobile first-instar larvae (triungulins) that parasitize solitary bees by hitchhiking to nest sites. Females are notably larger than males, reaching up to 19 mm.
Meloe dugesi
Meloe dugesi is a species of blister beetle (family Meloidae) described by Champion in 1891. It belongs to the genus Meloe, commonly known as oil beetles, which are characterized by their defensive production of cantharidins. The species occurs in Central America and North America. Like other members of its genus, it likely exhibits the typical Meloe life cycle involving triungulin larvae that parasitize solitary bees.
Meloe franciscanus
Meloe franciscanus is a blister beetle endemic to the southwestern United States. Adults are flightless and feed on Astragalus lentiginosus. The species is notable for its highly specialized larval parasitism of solitary bees in the genus Habropoda. First described from San Francisco dunes in 1928, the species was presumed locally extirpated there due to habitat loss but persists in other regions.
Meloe impressus
blister beetle, oil beetle
Meloe impressus is a species of blister beetle in the family Meloidae, native to North America. It belongs to a genus commonly known as oil beetles, characterized by their defensive secretion of cantharidin, a potent blistering agent. The species is recorded across western and central Canada and the United States. Like other Meloe species, it likely exhibits the complex life history involving parasitic larvae that exploit solitary bees as hosts, though specific details for this species remain poorly documented.
Meloidae
Blister Beetles
Meloidae, commonly known as blister beetles, is a family of approximately 7,500 species worldwide within the order Coleoptera. Members are characterized by their production of cantharidin, a toxic terpenoid compound that serves as a potent chemical defense against predators. The family exhibits remarkable diversity in adult morphology, with some species displaying aposematic coloration while others are cryptically colored. Life histories are complex, typically involving hypermetamorphosis with mobile triungulin larvae that often parasitize grasshopper eggs or bee nests. Adults are primarily herbivorous, with many species feeding on flowers and foliage of various plants.
Meloinae
blister beetles
Meloinae is a large subfamily of blister beetles (family Meloidae) containing at least 330 described species in multiple tribes distributed across the Holarctic, Neotropical, Afrotropical, and Oriental regions. The subfamily includes economically important genera such as Epicauta (crop pests), Meloe (oil beetles), and Lytta. Members exhibit diverse life histories, with some species being phytophagous adults and others showing complex larval associations with bees or grasshoppers. Sexual dimorphism and stereotyped courtship behaviors have been documented in multiple genera.
Ripiphoridae
wedge-shaped beetles
Ripiphoridae is a cosmopolitan family of approximately 450 described species of beetles commonly known as wedge-shaped beetles. The family is notable for hypermetamorphic parasitoid development, a trait shared only with Meloidae among beetles. Host associations vary by subfamily: Ripiphorinae attack bees and wasps, Ripidiinae parasitize cockroaches, and Pelecotominae attack wood-boring beetle larvae. The family exhibits extreme morphological modifications including abbreviated elytra, sexually dimorphic antennae (flabellate or pectinate in males), and in some groups, wingless larviform females.
Sosylus
Sosylus is a genus of dry bark beetles in the family Bothrideridae, containing approximately eight described species. These beetles are significant natural predators and parasites of ambrosia beetles (family Platypodidae). The genus has been documented in New Guinea and other regions, with species exhibiting distinctive triungulin-type first-instar larvae—a mobile larval form rare among beetles.
Tricrania sanguinipennis
Blood-winged Blister Beetle
Tricrania sanguinipennis is a flightless blister beetle (family Meloidae) native to eastern North America. Adults are 9–15 mm long with bright red, leathery elytra that conceal vestigial wings. The species is a parasitoid of solitary bees in the genus Colletes, particularly Colletes inaequalis. Its life cycle involves hypermetamorphosis, with a mobile triungulin larva that hitchhikes on male bees to access underground nest cells. The beetle has been documented from Saskatchewan to northern Florida, with Kansas marking its western limit.
Tricrania stansburyi
Stansbury's Blister Beetle
Tricrania stansburyi is a blister beetle in the family Meloidae. It is a cleptoparasite of solitary bees, specifically known to parasitize the mason bee Osmia lignaria propinqua. The species exhibits hypermetamorphosis, with triungulin larvae attaching to host bees to gain entry to nest cells. It is found in North America and is one of at least two species in the genus Tricrania.