Dobsonflies. Fierce looking hellgrammites, prized as bait by trout fishermen, are the aquatic progeny of awkward dobsonflies, such as the female in my picture.

Males and females, generally about two inches long, are found near water and at nearby street and porch lights. Adult males resemble females but are outfitted with long pincers they employ in mating. Both adult sexes are short-lived and harmless.

White, gauze-like secretions that attach dobsonfly eggs to large rocks are common in the Delaware River.