Identifications of Therevids

Identifications of organisms have traditionally been based on the ability to distinguish differences in key morphological characteristics among groups. Often these differences rely on the relative proportion of body parts to one another, the presence or absence of hairs, scales, or other ornamentation, and the relative size and shape of the genitalia. When flies or other insects are captured and pinned, characteristics like color may change after the animal dies, and often dessication obscures the true nature of a live fly, making identifications all the more difficult. Ideal keys allow the user to choose which characters to use to eliminate possibilities before arriving at an identification, but these are often complex to construct or require specialized software to display. Traditional keys are usually dichotomous, working with either/or couplets in a linear sequence that give the user no choice about the order or characters to be examined. Thus if a couplet in the key refers to a characteristic of the male fly and you have in your hand a female, you are stuck. Such keys are often published in traditional print media, however, and it is only now, with the availability of computers, that the less traditional keys are becoming more common.

For now, our web-based keys will still be modeled on their published counterparts.

A Key to the Stiletto-Flies of Australia

Austherevid contains all types of information related to the study of Australasian Stiletto-flies, including an interactive key to genera. [Requires Lucid3 player java applet]

A Key to the Nearctic Genera of Therevidae

This dichotomous key is taken from the following work:

Irwin, M. E., L. Lyneborg. 1981. The genera of Nearctic Therevidae. Illinois Natural History Bulletin (1980), 32: 193-277 (key on pp. 201-203).

Unless otherwise stated, all illustrations in this key are the work of Kai L. Elsman and Robert Nielsen.

A Key to Chromolepida

The key, illustrations, and descriptions of species of the genus Chromolepida are taken (with permission) from the following paper:

Webb, D. W. & M. E. Irwin. 1995. The new world genus Chromolepida Cole (Diptera: Therevidae: Therevinae). Proceedings of the Entomological Society of Washington, 97(1): 197-224.

A Key to Megalinga

The key, illustrations, and descriptions of species of the genus Megalinga are taken (with permission) from the following paper:

Webb, D. W. & M. E. Irwin. 1991b. The North American genus Megalinga Irwin and Lyneborg (Diptera: Therevidae: Therevinae). Proceedings of the Entomological Society of Washington, 93(4): 914-924.

A Key to Nebritus

The key, illustrations, and descriptions of species of the genus Nebritus are taken (with permission) from the following paper:

Webb, D. W. & M. E. Irwin. 1991a. The Nearctic genus Nebritus Coquillett (Diptera: Therevidae: Therevinae). Proceedings of the Entomological Society of Washington, 93(4): 899-913.

A Key to New World Ataenogera and Phycus
Description of genus Ataenogera
Biology of Ataenogera
Description of genus Phycus
Biology of Phycus

The key, illustrations, and descriptions of species of the genera Ataenogera and Phycus are taken (with permission) from the following paper:

Webb, D. W. & M. E. Irwin. 1988. The genera Ataenogera and Phycus in the New World (Diptera: Therevidae: Phycinae). Proceedings of the Entomological Society of Washington, 91(1): 35-50.

For your reference:

Labelled Parts of a Therevid Fly

head
antenna
thorax, lateral view
thorax, dorsal view
wing
legs
abdomen
male terminalia
female terminalia
larva (habitus photo)
pupa

Credits

Habitus photos of therevids

Phylogeny of therevids