Guido Nonveiller (1963) hypothesized the Mutillidae are generally stenothermic and thermophilic they may not avoid light, but rather are active during temperatures that usually occur only after sunset. Females of Tricholabiodes thisbe are sometimes active up to two hours before sunset. Although some species are strictly nocturnal, females are often active during the day. Members of the family Myrmosidae, formerly classified as a subfamily of mutillids, also have a distinct pronotum in females, but lack felt lines in both sexes.Īdult mutillids feed on nectar. Only two other vespoid families ( Bradynobaenidae and Chyphotidae) have felt lines, but the females of these families have a distinct pronotum, with a transverse suture separating it from the mesonotum in female mutillids, these two thoracic segments are completely fused. Both sexes of mutillids also bear hair-lined grooves on the side of the metasoma called felt lines. In both sexes, a structure called a stridulitrum on the metasoma is used to produce a squeaking or chirping sound when alarmed. The stinger is a modified female organ called an ovipositor, which is unusually long and maneuverable in mutillids. In some species, the male carries the smaller female aloft while mating, which is also seen in the related family Thynnidae.Īs is the case for all aculeates, only female mutillids are capable of inflicting a sting. The males and females are so distinct in their morphology that entomologists often find it very hard to determine whether a given male and female belong to the same species, unless they are captured while mating. As in some related families in the Vespoidea, males have wings, but females are wingless. Mutillids exhibit extreme sexual dimorphism.
This characteristic allows them to successfully invade the nests of their prey and also helps them retain moisture. The exoskeleton of all velvet ants is unusually tough (to the point that some entomologists have reported difficulty piercing them with steel pins when attempting to mount them for display in cabinets). Through the evolution of aposematic traits in velvet ant species in the same ring, local predators have learned to avoid these well-defended wasps. These mimicry rings are the result of repeated convergent evolution of aposematic traits between co-occurring velvet ant species, rather than shared phylogenetic history. North American Mutillidae have eight phenotypically distinct and geographically limited Müllerian mimicry rings (Desert, Eastern, Madrean, Texan, Red-headed Timulla, Black-headed Timulla, Tropical, and Western) making up one of the largest Müllerian mimicry complexes on the planet.
Over 400 species occur in the North American Southwest.
Mutillidae can be found worldwide with about 230 genera or subgenera and around 8,000 species worldwide. Unlike true ants, they are solitary, and lack complex social systems. In addition, the actual toxicity of their venom is much lower than that of honey bees or harvester ants. However, mutillids are not aggressive and sting only in defense. They are known for their extremely painful stings, (the sting of the species Dasymutilla klugii rated a 3 on the Schmidt pain index and lasts up to 30 minutes ), and has resulted in the common name "cow killer" or "cow ant" being applied to the species Dasymutilla occidentalis. Their bright colors serve as aposematic signals. Their common name velvet ant refers to their dense pile of hair, which most often is bright scarlet or orange, but may also be black, white, silver, or gold. The Mutillidae are a family of more than 7,000 species of wasps whose wingless females resemble large, hairy ants.
0 kommentar(er)
