Dobsonflies

Definition

A subfamily of large, soft-bodied neuropteran insects (Corydalinae, family Corydalidae, order Megaloptera) characterized by aquatic larvae and terrestrial adults often found near running water. Larvae, known as hellgrammites, are elongate, heavily sclerotized predators of stream benthos; adults possess conspicuously elongated mandibles in males of many species and reduced mouthparts. The group comprises nine genera distributed across the Americas, Asia, and South Africa, with Corydalus among the most species-rich and widely studied.

Etymology

From 'Dobson,' of obscure origin, possibly a surname or regional term; 'fly' from Old English fleoge, referring to the adult winged stage.

Example

Male Corydalus cornutus dobsonflies bear sickle-shaped mandibles up to half their body length, used in male-male combat and courtship displays but too large for feeding; larvae hunt caddisfly and mayfly nymphs in rocky riffles.

Synonyms

• Corydalinae

Related Terms

• Megaloptera
• Fishflies
• Hellgrammite
• Alderflies
• Aquatic insects
• Neuroptera

Usage Notes

Dobsonflies are distinguished from fishflies (Chauliodinae, same family) primarily by adult mandible morphology and larval habitat preferences; the common name 'dobsonfly' properly applies to the subfamily, though regional usage sometimes conflates it with fishflies. Larvae are frequently called hellgrammites in angling and ecological literature. The elongated male mandibles are a classic example of sexually selected exaggeration that imposes locomotor costs.