552 



AN INTRODUCTION TO ENTOMOLOGY 



Fig. 6j8.—Pan- 

 orpa, female. 



m 



(Fig. 677). For further details regarding the venation of the wings 

 in this order, see "The "Wings of Insects" (Comstock '18 a). 



The metamorphosis is complete. The larvae are caterpillar-like, 

 with three pairs of thoracic legs and with or without abdominal pro- 

 legs. The pupae are exarate, that is, the wings and legs are free, as 

 in the Coleoptera and H^Tnenoptera. 



This order is represented in our fauna by six genera ; these can be 

 separated by the following table : 



A. With well-developed wings. 



B. Wings long and narrow; ocelli present. 



C. Tarsi with a single claw, and fitted for grasping Bittacus 



CC. Tarsi with two claws, and not fitted for grasping. 



D. Tarsal claws toothed Panorpa 



DD. Tarsal claws simple Panorpodes 



BB. Wings comparatively wide, with many cross-veins extending from the 



subcosta to the costa; ocelli wanting Merope 



AA. Wings wanting or imperfectly developed. 



B. Without ocelli; small insects, less than 6 mm., in length BoREUS 



BB. Ocelli present; body about 20 mm., in length Apterobittacus 



Panorpa or the scorpion-flies. — The most common members of 

 this order belong to the genus Panorpa, of which there are nearly 



twenty described 



North American 



species. Figure 678 



represents a female 



of this genus. In 



our more common 



species the wings 



are yellowish, spot- 

 ted with black. The 



males of this genus 



are remarkable for 



the peculiar form of 



the caudal part of 



the abdomxcn (Fig. 



679). This at first 



sight reminds one of 



the corresponding 



part of a scorpion, 



and suggested the 



common name scor- 

 pion-flies for these 

 insects. But in reality the two are very different ; the last segment 

 of the male Panorpa, instead of ending in a sting, lilvc that of a scorpion, 

 is greatly enlarged and bears a pair of clasping organs. The tarsal 

 claws are toothed (Fig. 680, a). 



V. The adults are found resting on the surface of foliage of rank 

 herbage growing on the banks of shaded streams and in damp woods 

 where there is a luxuriant undergrowth of herbaceous plants. They 

 feed on dead or injured insects and upon fruits; it appears that they 

 rarely if ever capture living prey. 



Fig. 679. — Abdomen of 

 Panorpa rufescens. 



C 



Fig. 680. — a, fore leg of Pan- 

 orpa; h, last two segments 

 of tarsus of Bittacus, ap- 

 posed; c, last three seg- 

 ments of tarsus of Bittacus. 



