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AN INTRODUCTION TO ENTOMOLOGY 



enough to droop. The falling spray lodges in the blossom end of the 

 young apple, and many of the larvaj which attempt to enter at this 

 point, the usual place of entrance, get a dose of poison with their 



first meal. 



The pine-twig moths, 

 Evetria. — The genus, Eve- 

 rtia includes many spe- 

 cies that infest the twigs 

 and smaller branches of 

 various species of pine. 

 Some of our best known 

 species were described 

 under the generic name 

 Retinia but now the old- 

 er name Evetria is applied 

 to them. The following 

 species are well-known. 

 Evetria comstockidna. 

 — This species (Fig. 783) 

 illustrates well the hab- 

 its of the boring species. 

 The larva inf eststhe small 

 branches of pitch-pine. 

 It is a yellowish-brown 

 caterpillar, which makes 

 a burrow along the cen- 

 tre of, the branch. Its 

 presence may be detect- 

 ed by the resin that flows 

 out of the wound in the 

 twig and hardens into a 

 lump. Two of these 

 lumps are shown in the 

 figure, one of them split 

 lengthwise, and the oth- 

 er with a pupa-skin pro- 

 jecting from it. The lar- 

 va, pupa, and adult are 

 also figured. The moth 



Fig. 783. — Evetria comstockiana: larva, pupa, 

 adult, and work. (From the Author's Report 

 for 1879.) 



is represented natural size; the darker shades are dark rust-color, 

 and the lighter, light-gray. The insect winters as a larva; the adult 

 emerges in May and June. 



Evetria frustr ana. — This species infests the new growth of several 

 species of pine, spinning a delicate web around the terminal bud, and 

 mining both the twig and the bases of the leaves. The larva, pupa, 

 and aclult are represented somewhat enlarged in the figure. An in- 

 fested twig is also shown (Fig. 784). 



The grape-berry moth, Polychrosis vitedna. — The most common 

 cause of wormy grapes is the larva of this moth. The moth emerges 



