Family Evaniidae - Ensign Wasps

Cockroach Egg Parasitoid Wasps; Hatchet Wasps; Nightshade Wasps

Evaniidae Latreille 1802

11 spp. in 4 genera in our area(1), ~440 spp. in >30 genera total

in our spp., forewing length from 2.5 mm (Hyptia floridana) to 7.5 mm (Prosevania fuscipes)(2)

The gaster is very small and oval, attached by a slender petiole to the propodeum, considerably above the base of the hind coxae. It is carried almost like a flag (thus the name).

keys to NA taxa(3)

Overview of Genera

1. Hyptia - our only genus with the fore wing venation simple, forming a single enclosed cell; also unique in lacking or partially lacking notauli; species ranging from entirely black to entirely ferruginous

2. Evania - our only genus with the fore, mid, and hind coxae spaced evenly; our single species readily distinguished by its large size (at 5.5 - 7 mm forewing length, only rivaled by Prosevania fuscipes), entirely black body, and distinctive blue eyes

3. Evaniella - our only genus with the fore wing having multiple cells and a length of 5.0 mm or less; species often marked with ferruginous

4. Prosevania - our only genus with a large size (at 5.5 - 7 mm forewing length, only rivaled by Evania appendigaster) and close spacing of the mid and hind coxae; our single species only recorded from urban environments is further noted by its long scapes, robust thorax, and dark coloration often with brown on the extremities

much of the world; in NA, eastern and southwestern(1)

Hyptia and Evaniella are found primarily in the woods. The introduced genera, Evania and Prosevania, are more often found in buildings in the cities, around where introduced species of cockroaches frequently occur.(1)

Parasitoids of the egg capsules of cockroaches

Females have very short and stout ovipositors. They prefer newly laid eggs that have not developed hard, impervious coats. Each cockroach egg case contains about 50 eggs. Eating only a few provide sufficient food the the single wasp larva.(4)

When searching for their host, the wasps pump their posterior end rhythmically up and down, like a chopping of a hatchet.(4)