Alderflies, Dobsonflies, and Fishflies

Order Megaloptera

The Alderflies, Dobsonflies, and Fishflies (Order Megaloptera) includes 49 species across 2 families and 9 genera in our directory.

About Alderflies, Dobsonflies, and Fishflies

Megaloptera (dobsonflies, fishflies, alderflies) includes ~380 described species. Male dobsonflies have enormous mandibles up to 40mm long - longer than their entire head - used in combat with rival males.

Economic Impact

Hellgrammites (dobsonfly larvae) are prized bait for bass fishing across North America. They are also important bioindicator species for freshwater stream health monitoring.

Ecological Role

Dobsonfly larvae (hellgrammites) are top predators in stream ecosystems, spending 2-5 years as aquatic nymphs before pupating. They can grow up to 90mm long, making them some of the largest aquatic insect larvae in North America.

Families in Megaloptera (2)

Species in Megaloptera (49)

Banded Dark Fishfly

Nigronia fasciata

Corydalidae

Identification: Wings are dark brown with an off-white (not bright white) stripe across the middle of the wings. The stripe extends from outside edge (costa) to just before inner wing margin and always has several brown spots, especially on the base

Corydalus luteus

Corydalidae

Identification: South Texas species distinguished from its allies by the solidly tan color of the head and thorax, lacking the pale markings found in C. cornutus and C. texanus . The many pale spots in the wings are not margined by a dark wing. Males

Dysmicohermes ingens

Corydalidae

Identification: closely related to D. disjunctus (Walker) but in the latter the wing spots are larger, more intense and the membrane more hyaline, the head is less strongly punctured and more rugose, the ocelli a little smaller and the transverse pos

Neohermes angusticollis

Corydalidae

Identification: See individual images here. Similar to Neohermes concolor . Males can be identified by examination of terminalia (Bowles and Mathis, 1992): That third thumbnail resembles angusticollis , currently listed at genus level. Compare male c

Neohermes inexpectatus

Corydalidae

Identification: Dark markings in forewing indistinct and distant or reduced along the longitudinal veins; distinguished from similar Protochauliodes by the crossvein beyond posterior Rs branch fork of the forewing. Described from material collected d

Orohermes crepusculus

Corydalidae

Identification: Posterior branch of Rs branched in both wings; posterior branch of M simple in hind wing; thoracic vestiture short and sparse ( vs long & wooly); male 10th tergite short ( vs elongate and deeply notched); female 10th tergite bifid, th

Saw-combed Fishfly

Nigronia serricornis

Corydalidae

Identification: Wings: Dark brown with a narrow uneven white stripe across mid wing, not complete; or a very wide, bright white stripe without the dark spots on base half of stripe. Some white spots near wing tip. Hind wing dark brown with white spot

Sialis rotunda

Sialidae

Identification: Larvae are distinguished from other western species by the pale dorsal stripe on the abdomen.

Western Dobsonfly

Corydalus texanus

Corydalidae

Identification: Western species with pale markings on the head and with the pale spots in the wing conspicuously margined by a dark ring. Though males have longer mandibles than the females, they are shorter than those of the males in our other speci