Facultative-sex-allocation
Guides
Sphaeropthalma pensylvanica
velvet ant
Sphaeropthalma pensylvanica is a velvet ant (family Mutillidae), a group of solitary wasps known for their striking aposematic coloration and painful sting. The species exhibits notable sexual dimorphism: females are wingless and resemble ants, while males possess wings. It has been documented as a parasitoid of mud dauber wasps, particularly developing within cocoons of the organ pipe mud dauber (Trypoxylon politum). Research has revealed unusual reproductive characteristics including facultative size-dependent sex allocation, where larger females produce proportionally more female offspring. The species is also notable for phoretic copulation, a mating behavior in which the male transports the female by flight or foot from the initial contact site before mating occurs.