John Boland, age 14, of Chillicothe, Illinois, for his question:

What do hellgrammites eat?

The U.S. mails ban the shipment of living insects with the exception of honeybees, mealybugs, silkworms    and hellgrammites. Obviously these insects are no threat and have special qualities that make them beneficial. The hellgrammite's good qualities are twofold, both related to his role in the food chain that supports the ecology of ponds and streams. He devours an assortment of small aquatic creatures, some of which prey on fishes. He also reduces the mosquito population by devouring their eggs and newly hatched larvae.

The hellgrammite is a frisky little wriggler, and very attractive to hungry fishes. When captured, he is sold as bait and fishermen use. him to catch bass. Actually he is a larval insect and later he changes into a pupa stage. After about two weeks, he emerges as a delicate dobsonfly with a big head, rather long antennas and four gauzy wings. His adult life lasts just long enough to produce eggs destined to hatch in the water and become the next generation of hungry hellgrammites.