Eastern Dobsonfly
Corydalus cornutus
Classification
- Phylum: Arthropoda
- Subphylum: Hexapoda
- Class: Insecta
- Order: Megaloptera
- Family: Corydalidae
- Subfamily: Corydalinae
- Genus: Corydalus
- Species: cornutus
Pronunciation
How to pronounce Corydalus cornutus: //kɔːˈrɪdələs kɔːrˈnuːtəs//
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Summary
The Eastern Dobsonfly, Corydalus cornutus, is a large insect found in eastern North America. Its aquatic larvae, known as hellgrammites, are important predators in freshwater ecosystems and are sought after as fishing bait. The adults are non-feeding and are characterized by their impressive size and striking reproductive behaviors.
Physical Characteristics
Adult: body 48-60 mm, wingspan up to 125 mm; larva up to 70 mm. Eggs are grey and cylindrical, about 1.4 mm long and 0.5 mm wide.
Identification Tips
Males have enlarged, sickle-shaped mandibles measuring up to 40 mm long. The body has pale markings on the head and many pale spots in the wings not margined by a dark ring. The thorax is distinct in shape compared to Chauliodes species.
Habitat
Found in fast-flowing, unpolluted streams in eastern North America.
Distribution
Widespread in eastern North America, typically in regions with swift-flowing streams.
Diet
Larvae are predatory, feeding on soft-bodied invertebrates; adults do not feed.
Life Cycle
Eggs laid close to water, hatch after 1-2 weeks. Larvae develop for 1-3 years, pupate into a chamber in moist soil; adults emerge in spring to summer.
Reproduction
Eggs are laid in masses of 100-1,000 on rocks or vegetation above waterline. Females use a clear protective fluid for the egg mass.
Ecosystem Role
Hellgrammite larvae are among the top invertebrate predators in aquatic ecosystems.
Economic Impact
Hellgrammites are used by anglers as bait for fishing.
Cultural Significance
Common names like 'dobsonfly' and 'hellgrammite' have unknown etymologies, noted in early 20th-century literature. Some references indicate southern Appalachian origins for these names.
Collecting Methods
- Using nets in streams where larvae are found.
- Attracting adults with lights at night.
Preservation Methods
- Pinning adults for display.
- Preserving larvae and pupae in ethanol.
Similar Taxa
Misconceptions
The term 'dobson' may not have a definitive origin; speculation links it to Native American terms or other aquatic creatures.
Tags
- Corydalus
- dobsonfly
- hellgrammite
- Megaloptera
- predatory insects