The secret lives of Hellgrammites

8:25 AM, Sep 5, 2013   |    comments
  • Share
  • Print
  • - A A A +


(News-Press) -- So, they're not the prettiest creatures in Southwest Florida, but that's OK because you probably haven't come across one. That is, of course, unless you are a fisherman or are prone to hang out where they are: around rocks in flowing rivers and creeks.

Theses aquatic creatures grow to about 3.5 inches in length, and have physiological traits that allow them to breathe in and out of water. They are brown, and the first eight segments of their abdomens are covered with prickly microspines (called lateral tactile filaments), which "protect them from each other and from other small predators," according to the University of Florida (UF) Institute of Food and Agricultural Sciences.

That's just the beginning of their aggressive defense mechanisms. They also have hard body plates and large mandible pinchers used to grab aquatic insects and other morsels as they hang, attached to a rock, collecting their meal as it flows by. If you're collecting these fierce little creatures for bait for smallmouth bass and game fish, or just happen to be dangling your feet around their hangout, you can receive a mighty little pinch that can draw blood.

That's what happened to Grant Gilmore, 9, when he and his cousin were picking up rocks one day in the Orange River. Grant got pinched at the topmost of his oh-so-tender Achilles' heel, and it left two indelible red marks for days. "It felt like a pin going through it," he recalls. "It burned, stung and itched."

But this is only the beginning for these critters, which are actually the larvae form of the Eastern dobsonfly. Dobsonflies deposit clusters of some 1,000 eggs on leaves or other ideal places dangling near and over the water. They cover the cluster with a clear fluid that dries white; the cluster looks like bird droppings on a leaf, according to UF. The eggs only hatch at night, and the larva float until locating a suitable rock or snag to develop for up to three years. When they're ready, they crawl into a moist place to pupate and all take flight simultaneously as the four-winged Eastern dobsonfly, which can grow longer than 5 inches. Females, though not the males, retain the blood-drawing pinchers.

But again, you likely won't come across one, except when they're drawn to artificial lights at night. The dobsonflies are reclusive, hiding under vegetation along the river, and only move about at night. They are not known to eat anything in nature, and are short-lived: Males live only three days, and females up to 10 days, according to UF.

The good news about hellgrammites is that they are indicators of clean, unpolluted waters.

Longtime fans of DC Comics may recognize these creatures through the character called Hellgrammite - an entomologist named Roderick Rose who transforms himself into a villainous superhuman grasshopper-humanoid.

Most Watched Videos