Numbers
32 extant spp. in 2 genera in our area
(1)(2), ~170 described spp. in 3 genera worldwide + about as many undescribed
(3)
1. Aulacus Jurine, 1807 (9 spp.)
2. Pristaulacus Kieffer, 1900 (23 spp. + 1 fossil sp.)
Identification
Resemble Gasteruptiidae, but our spp. are usually black with reddish abdomen, longer antennae, and two recurring veins in the front wing.
The genera are separated based on the following traits of wing venation (see
labeled diagram):
(3)
Aulacus - has a 2r-m vein and a longer 2-Rs+M vein.
Pristaulacus - lacks a 2r-m vein and has a shortened 2-Rs+M vein.
Range
most of the world, more diverse in the tropics
(3)Habitat
Adults usually found around logs where hosts occur
Food
endoparasitoids of the wood-boring larvae of beetles (of several families, but mostly longhorns) and
Xiphydria wood wasps
(3)Life Cycle
The host larva and the Aulacid larva start out at about the same stage and size, the aulacid larva prolongs development until the host is full size. Then is devours it. When mature, the larva leaves the empty cuticular shell of the host, spins a cocoon, and pupates.
(4)Remarks
Frequently mistaken for ichneumonid wasps as they often frequent dead standing trees, logs, woodpiles. Note "neck" between head and thorax and the high attachment point of the metasoma
Print References
Smith, A.S. 2008. Aulacidae of the southwestern United States, Mexico, and Central America (Hymenoptera). Beitrage zur Entomologie 58: 267-355.