4 inches long
There are over 220 species of dobsonfly so you'll have to be more specific in telling us what you want to know.
No, we just caught one in my front yard. It is not extinct.
A Dobsonfly is a large insect with long mandibles, prominent eyes, and clear wings. Males have long mandibles that resemble antlers, while females have shorter, stouter mandibles. They are usually brown or black in color and are known for their intimidating appearance.
dobsonfly live near bodies of water for that most part, they spend most of their lives in the larval states as water creatures, when they grow up they live for only seven days or so and primarily live near the body of water from which they were born.
If it's the same thing we called a "helgermite" back when I lived in WV, it's actually called a Dobsonfly. They are a variety of insects native to the Americas, Asia and Africa.
Dobsonflies eat small bugs and some plants
Being as all bugs and beetles have 6 legs and antennae, the description is not much to go on. Further, masses of beetles are about an inch long and brown. Be a bit more descriptive and you may get an answer. I suggest a cockroach as one possibility, but exactly how thin do you mean.
Dobsonfly larvae, commonly known as hellgrammites, are primarily preyed upon by various aquatic predators, including fish such as trout and bass. They are also vulnerable to larger insects, amphibians, and birds. The larvae's habitat in freshwater environments makes them a key food source for these predators, contributing to the aquatic food web. Their tough exoskeletons can provide some protection, but they remain an essential part of the diet for many species.
The insect you are describing is likely a female dobsonfly. Female dobsonflies are known for their long wingspan, brownish-black color, and distinctive appearance that can resemble a small fruit. They are commonly found near water sources like bathrooms due to their preference for moist environments.
A helgramite is the larval form of the dobsonfly. They are aquatic insects found in streams and rivers, known for their large, aggressive appearance with powerful mandibles. Helgramites are commonly used as bait by fishermen due to their attractiveness to fish like bass and trout.
There aren't any known insects with large tentacles. However, the male dobsonfly appears to have tentacle-like structures coming out of its mouth. Although male dobsonflies have large mandibles, they are harmless since they are too weak to break human skin. However, the females' smaller mandibles are capable of delivering a painful bite.
I have kept a couple adult specimens for a short time. Unfortunately, their life cycle is all but finished once they reach their adult phase. I kept a female specimen for three months, and I even observed her feeding in the face of convenitonal wisdom that states the adults do not eat. If you really want a challenge, find the larvae- hellgrammites- and raise them in fast running water until they pupate.