#corydalidae

A Hellgrammite, the aquatic larva of an Eastern Dobsonfly (Corydalus cornutus), family Corydalidae, found in a freshwater creek in Ohio, USA

Yay! I’ve finally found an adult dobsonfly and she’s beautiful 😍

I know this is a female because of her mouthparts. Males of this species have huge mandibles, but despite their intimidating appearance, they can’t really bite. Females, however, can deliver a painful bite in self-defense.

Dobsonflies can get rather large. For scale, her body is 2.5 inches (6.35 cm) long!

Their larvae (aka hellgrammites) are vicious aquatic predators. Adults are not thought to eat and only live for about a week.

so my post of these bugs with the little bows has been getting really popular and i got some questions about what they are:

these are hellgrammites, the aquatic larvae of dobsonflies (order megaloptera: family corydalidae: subfamily corydalinae)! not centipedes, but insects. they have 6 true legs at the front. the other leggy things on the back are lateral filaments for tactile sensing and breathing. they also have abdominal gill tufts on their bellies and a pair of spiracles on their butts for the air.

this hellgrammite (eastern dobsonfly, corydalus cornutus) is out on the pavement because they can actually crawl pretty far from the water to find a place to pupate under a log or rock. if you know someone who fishes, they might know about these (as well as where to find them!) because they make good bait. some fishermen even make cool lures based off them!

^eastern dobsonfly pupa!! like beetles, their limbs and other appendages are free unlike the smooth casing of many flies and moths.

as adults, they're generally large flying insects though they don't fly super well. many are also easily recognizable because the males often have GIANT curved mandibles. despite this, they're actually too cumbersome to bite you. females will give you a strong pinch but only if you manhandle them. the adults also only live a few weeks compared to the few years (many insects are like this) that hellgrammites spend as ambush predators under large rocks in cold, fast-flowing streams. because of their specific habitat requirements, hellgrammites' change in abundance in streams can be really important for monitoring stream health.

^male eastern dobsonfly. he is so polite for taking time out of his night to pose for this photo

so you know how there's like. 400,000 species of beetles and 180,000 species of moths and butterflies? megaloptera only have 400 species!! and dobonsflies are only part of that group alongside alderflies and fishflies!! while megaloptera as a whole are found on every continent, dobsonflies are absent from huge portions of north america, europe, africa, and australia. globally speaking, they're kind of an uncommon insect. so to my fellow bug nerds in southwest/eastern north america, south america, and eastern/southeast asia, think about your local hellgrammites :3

^figure from jiang et al. 2021 showing global distributions of corydalinae. their wacko distribution is probably the result of regional extinctions since they need specific habitats and can't fly very far.

some more dobsonfly friends from around the world:

^protohermes, a genus of dobsonfly from asia. lemony fresh

^platyneuromus, a genus of dobsonfly from south america. seems like a good listener (they're not actually ears, just extensions of the head, and are probably for sexual display)

^chloroniella, the one genus of dobsonfly in southern africa. tiny!!

Bug of the not-really-sure-but-it's-been-awhile

Somebody needs a comb!! ;-)

This is a male dobsonfly! They’re a really cool predatory species. I’m not sure if the specific species but Brazil has Corydalus affinis, Corydalus amazonas, and Corydalus armatus.

Ok, Mermay is almost over and I've had this WIP sitting on my computer for weeks at this point.... It's a concept and it's not even close to finished but I wanted to get it out before the month is over lol

Hellgrammite mermaid!!! Centaur? What would this be called.... The larval stage of Dobsonfly are aquatic but they aren't called naiads... and have legs... can mermaids be aquatic insects??? Most aquatic insects are just aquatic until their adult stage though..... Could do riffle beetles.... Idk and Imma stop dwelling on it

eastern dobsonfly female, some kind of inchworm moth (one spotted variant probably, but what kind of name is that?), some sort of roundback slug (probably western dusky slug)

and.. if you stayed this long... some previous friends as a surprise!