Evania appendigaster | |
---|---|
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Superfamily: | Evanioidea |
Family: | Evaniidae |
Genus: | Evania |
Species: | E. appendigaster |
Binomial name | |
Evania appendigaster Linnaeus, 1758 |
|
Synonyms | |
Evania affinis |
Evania affinis
Evania cubae
Evania desjardinsi
Evania laevigata
Evania peringueyi
Evania unicolor
Evania appendigaster is a species of wasp in the family Evaniidae, the ensign wasps. Its native range is not known, but it likely originated in Asia. Today it occurs throughout the tropics and subtropics and in many temperate regions. It is a parasitoid wasp known for specializing on cockroaches.
This is one of the larger ensign wasps, with forewings up to about 7 millimeters long. It is distinguished from other species by the wide separation of the first and second sections of the coxa, the segment of the leg that attaches to the body. It is black in color. The abdominal petiole, the constricted stalk that holds the posterior section of the abdomen, or gaster, is attached high on the body. The gaster is laterally compressed and oval to nearly triangular in shape, held in a flaglike fashion and resembling an ensign, a characteristic of the family that inspired the common name ensign wasp.
This wasp reproduces by laying eggs in the egg cases, or oothecae, of cockroaches. The wasp larvae use the cockroach eggs as a food source. Host cockroaches include the American cockroach (Periplaneta americana), Australian cockroach (P. australasiae), brown cockroach (P. brunnea), Oriental cockroach (Blatta orientalis), whitemargined cockroach (Melanozosteria soror), and harlequin cockroach (Neostylopyga rhombifolia).
Detailed descriptions of the oviposition process in this species have been published. As one 1920 account describes it, "the Evaniid left the inside wall of the confining tumbler, ran over the Blattid ootheca, crawled over the surface momentarily as she actively vibrated her antenna and finally settled upon it with the long axis of her body parallel with the long axis of the egg mass as it lay upon its right side. Having satisfactorily settled herself, lying upon her right side she extended her ovipositor and crawling slightly forward she punctured the ootheca in the fifth egg cell of the left side, remaining in position for about fifteen minutes. She then left the egg mass and resting upon the inside wall of the tumbler actively cleaned the ovipositor, wings and antennae."