FIELD BOOK OF INSECTS. 



tree free from this species, it may be kept free by banding 

 the trunk with sticky paper, or the like, unless the tree 

 is so close to others that larvss may be blown to it. The 

 reason back of this protective method is that the females 

 can not fly. 



Porthetria 



About 1868 an amateur entomologist in 

 Massachusetts- was breeding the Gypsy 

 Moth (Plate LVI), using material which he 

 had obtained from Europe. His reason for doing this has 

 been variously stated; an excuse, which might now be 

 made for him, is that "he did not know it was loaded." 

 At any rate, some of the specimens went off and started to 

 colonize America. Alillions of dollars have since been 

 spent in an effort, so far unsuccessful, to free us from the 

 invader; the most that has been done has been to confine 

 it to New England. The United States Bureau of Entomo- 

 logy is now engaged in an attempt to introduce from Europe 

 parasites which there hold it, and the Brown-tail Moth, 

 in check. The male Gypsy Moth is olive-brown; the 

 whitish female rarely flies and then but feebly, although 

 the wings are rather well developed. Adults appear from 

 June to September but most abundantly in early July. 

 The eggs, which are yellowish, nearly globular, and about 

 a twentieth of an inch in diameter, are laid in masses of 

 from less than 200 to more than 1000 and covered with buff- 

 colored scales from the underside of the female's abdomen 

 (See Plate LVI). These masses are placed anywhere that 

 the female happens to be ; as she does not crawl far from the 

 pupal shell in which she dwelt and as the larvae are much 

 given to pupating under overhanging stones, on fences, 

 buildings, wagons, railroad cars, and the like, as well as 

 on vegetation, there is where the eggs are to be found. 

 Though the larvae may develop in a few weeks, they rarely 

 hatch until the next April or May. More than five 

 hundred species of plants, including conifers, are in their 

 dietary. The full-grown larva is about 2.25 inches long, 

 brownish-yellow with long hairs and four rows of tubercles; 

 there is one tubercle of each row on each segment, those 

 on the anterior segments being blue, those (especially of 

 the two middle rows) on the posterior segments being red. 



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