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Family Panorpidae

The representatives of this family in the United States are all contained in the genera Panorpa, Bittacus and Boreus. The true scorpion flies are very common insects in midsummer in most parts of the United States. Some of them have beautiful, spotted wings and are seen flying in the bright sunlight in places where tall herbage abounds. At my country place in the Catskill Mountains they are extremely abundant towards the end of July, flying from one blackberry bush to another and resting frequently upon the golden-rod plants. All Panorpids are carnivorous, but Panorpa has not been observed in this country to capture other insects as does Bittacus. The development of these insects was unknown until the Austrian entomologist, Brauer, in 1863, succeeded in obtaining eggs and rearing the insect. The larvae of Panorpa and Bittacus are found near the surface of the ground and feed upon dead animals, including such soft-bodied insects as caterpillars and grubs. The other genus, Boreus, is composed of wingless forms which look something like minute wingless grasshoppers. They occur in winter upon snow in our Northern States.

Life History of a Scorpion Fly

(Panorpa rufescens Ramb.)

This species, which is common in our Northern States, is the first Panorpid to be carefully studied in this country. It was found commonly at Ithaca, N. Y., in the summer of 1895, by Dr. E. P. Felt, flying in moist woods during July and August and especially along streams and where nettles abounded. After confining several females in breeding cages the eggs were obtained. They were laid in an irregular mass, were yellowish white in color, from twenty-four to twenty-nine in each cluster, and from 1 cm. to 2 cm. below the surface of the ground. The earth was moist and the larvae hatched in from six to seven days. The young larva when first hatched is whitish, with a light brown head which becomes darker when the body becomes gray. It looks like a caterpillar but the antennae and the eyes are unusually prominent. The abdomen bears a row of ringed spines down the back, those toward the anal end of the body being longer. The larvae pass through several stages of growth within the first two weeks. They burrow into little tunnels under the surface of the ground and remain underground most of the time. They were fed upon raw meat placed upon the surface of the ground. Sometimes they come out of their burrows for feeding. They are cannibalistic and the stronger ones destroy the weaker ones. They wander in search of food and feed upon all sorts of dead flesh. They reach full growth in from three to four weeks, burrow deeper into the ground, excavate another cell, and remain as larvae for several months before entering the pupa state. There seems to be but one generation annually, the adults issuing in midsummer.