236 Nerve-winged Insects; Scorpion-flies; Caddis-flies 



Simple eyes (ocelli) absent. 



Wings well developed; antennae short and thick; body more than J inch long. 



MEROPE. 



Wings rudimentary; antennas slender; body less than \ inch long BOREUS. 



Simple eyes (ocelli) present. 



Abdomen slender, cylindrical; not ending, in males, in swollen tip with clasping-organ. 



BITTACUS. 



Abdomen more robust, and in males conspicuously swollen and curved at tip, and 

 bearing pointed clasping-organ. 



Beak elongate, tarsal claws toothed PANORPA. 



Beak short, triangular; tarsal claws simple PANORPODES. 



Boreus is the genus of minute leaping black insects which appear occa- 

 sionally in snow. Four species occur in this country, one, B. calif ornicus . 

 on the Pacific coast, two in the northern and northeastern states, and one, 

 B. unicolor, found, so far, only in Montana. Of the two eastern species, the 

 snow-born Boreus, B. nivoriundus, is shining or brownish black, with the 

 rudimentary wings tawny; the other, called the midwinter Boreus, B. 

 brumalis, is deep black-green. Comstock says that both species are found 

 on the snow in New York throughout the entire winter, and that they also 

 occur in moss or tree-trunks. The females have a curved ovipositor nearly 

 as long as the tiny body. Neither their feeding-habit nor life-history is 

 known. 



The genus Panorpa includes the scorpion-flies, of which fifteen species 

 are found in the United States. These insects are from to f inch long, 

 with the wings of about the same length. In all, the body is brownish to 

 blackish and the wings are clear but weakly colored with yellowish or 

 brownish, and have a few darker spots or blotches, which in one or two 

 species cover nearly the whole wing-surface. Part of the head projects 

 downwards as a short thick beak, the mouth and jaws 

 being at the end. The few observations made on the 

 feeding-habits seem to show that the scorpion-flies sub- 

 sist mainly on animal matter found dead. They have 



FIG. 326. 



FIG. 327. 



FIG. 326. A scorpion-fly, Panorpa rufescens. (Twice natural size.) 



FIG. 327. Larva of scorpion-fly, Panorpa sp. (After Felt; three times natural size.) 



been seen to attack living injured and helpless insects. Panorpa rufescens 



