DOBSONFLIES AND ALDERFLIES (MEGALOPTERA) OF BRITISH COLUMBIA

Dysmiochermes disjunctus, photo by Darren Copley

by

R. A. Cannings and G. G. E. Scudder 

Copyright © 2007 - All rights reserved

Extracted from the forthcoming publication The Insect Families of British Columbia

Introduction (draft only)

Dobsonflies and Alderflies are medium to large, soft-bodied insects. The head is prognathous, with mandibulate mouthparts. The antennae are slender, multisegmented, and filiform, moniliform, serrate, pectinate or flaballate. The head may or may not have ocelli. The pronotum is subquadrate in dorsal view. The wings are relatively large, are held roof-like over the abdomen when at rest, and are often pigmented. The longitudinal wing veins are normally unbranched at the wing margins, and the hindwings are characteristically broader than the forewings and with a large anal area. The legs are cursorial and unmodified, with 5-segmented tarsi. The abdomen lacks terminal cerci.

Adults have a slow, clumsy flight, and either do not feed or at most feed on small quantities of nectar or fruit juices.

Larvae are aquatic and predaceous with biting mouthparts, a distinct labrum and maxillary palps. They are elongate, with characteristic lateral abdominal filaments, but they do not spin cocoons. 

There are two extant families.

Note:

This write up is extracted from the forthcoming publication by Scudder and Cannings:  the Insect Families of British Columbia. 
Illustrations by L. L. Lucas.  Copyright © 2005 - All rights reserved