Natural History
Acrotaphus is one of 15 genera of the tribe Polysphinctini. The genus
Acrotaphus is fairly small with seven species described in the Carribean
and tropical American habitats. Only one species occur in southeastern
United States (Acrotaphus witii).
The species of this genus are usually parasites of arachnids. They are
solitary koinobiont ectoparasitoids of such hosts. The female generally
attack an adult spider injecting a substance causing a temporary paralysis
of the host (Nielsen, 1923, Cushman,1926). It then attaches a single egg
to the host. As the parasitoid grows it eventually consumes the host spider.
When the larvae has consumed its host, it has been observed to spin a
coccoon in the spiders web. The Acrotaphus species spin white or golden
coccoons. Some species of Acrotaphus are believed to detect and be attracted to cues derived from spider silk as an important part of their host-location process. Many Acrotaphus species are nocturnally active, which has been speculated to be an adaptation to exploit hosts like the orb-web spiders that only have webs during night (Gauld, 1991).
The species of Acrotaphus are small to fairly large insects, with a forewing length of 6-18 mm. They are commonly orange with black markings on the metasoma or hind legs. the wings are generally yellowish with black bands. The metasoma is slender and ovipositor about 1.1-1.7 times as long as the hind tibia. (Townes & Townes, 1960: 256 as cited by Gauld, 1991. p322)"(Gauld)
The computerized indentification guide is not yet under construction. However, a guide may be found in Key in Genera of Ichneumonidea, part 2 by Townes. Sorry for any inconviences.
Burks, B.D., Paul D. Hurd, Jr., Karl V. Krombein, and David P. Smith. 1979. Catalog of Hymenoptera in America North of Mexico. Smithsonian Institution Press.Washington D.C.
Gauld, I. The Ichneumonidae of Costa Rica. n47.
1991. Memoirs of the American Entomological Institute. Florida.
Thanks to the members of Dr. Pickering's lab team
including Dr. Pickering, Ryan, Elizabeth, Brian, Jessica and others
that helped with information and the develpment of this page.
