ROSS: HOW TO COLLECT AND PRESERVE INSECTS 



49 



In one group of moths, there are clear "windows" on the wings, 

 but these are always surrounded by areas or lines of scales. A few 

 species of the Lepidoptera are very odd in having wingless 



Fig. 53. — Lepidoptera. 

 Hellula undalis, one of the 

 cabbage webworms; a, 

 adult; b, larva, side view; 

 c, larva, top view; d, the 

 pupa or transformation 

 stage from which the adult 

 emerges. The actual 

 length of the adult insect 

 is about 0.3 inch; its wing- 

 spread is about 0.8 inch. 



females. Examples are the bagworms and some of the canker- 

 worms. In these species, however, the body of the female is 

 densely clothed with scales, which will serve to identify her as 

 one of the Lepidoptera. 



The habits of Lepidoptera larvae are very diverse. Most of these 

 larvae are leaf eaters, but some bore into trunks of trees and 

 stems of plants. Some of the small ones mine within leaf tissue, 

 others live in the ground, where they eat roots, and a few are 

 aquatic, living in clear, rapidly flowing streams. 



Diptera Insects with only one pair of wings, these 



Flies, with only a limited number of veins. Other 



Mosquitoes, characters of the order, including antennae 



and Their and mouthparts, are extremely varied. Most 



Allies immature stages are wormlike or maggotlike 



and always live in some protected situation 

 such as within the tissues of a plant, in water, in leaf mold, or 

 in the tissues of animals. A typical life cycle is that shown for 

 the common onion maggot, Hylemyia antiqua (Meigan), fig. 54. 

 The ubiquitous house fly is undoubtedly the best known repre- 

 sentative of this order. It is also one of our most persistent 

 and dangerous insect pests, when its record as a possible carrier 

 of many diseases and internal parasites is considered. 

 Mosquitoes, punkies, black flies, and horse flies are equally well- 



