36 



FARMERS BULLETIN 843. 



FIG. 41. The oak or hickory cossid ( CossuU magni- 

 fied). Adult, or moth. Very slightly enlarged. 



DESCRIPTION. 



The moth (fig. 41) generally is gray, mottled with brown and 

 black blotches, and has an expanse of wings of about one and three- 

 fourths inches. Each forewing has a large, light brown patch, sprin- 

 kled at the end with dark-brown 

 streaks. The hind wings are 

 darker gray than the fore wings 

 and are without any markings. 

 The head is brown, the thorax 

 light gray, peppered with faint 

 dark spots, and the abdomen 

 brownish gray. 



The full-grown larva (fig. 42) 

 is about 1 1 inches in length. The 

 body is pinkish in general color 

 and covered sparsely with short 



fine hairs which arise from the numerous tubercles. The head, cervi- 

 cal shield, or neck, and plates on the hind end of the body are shiny 

 dark brown. 



The pupa, to which the larva transforms upon attaining full 

 growth, is generally brown, except the anterior part, which is black- 

 ish. On its head is a sharp projection which is of 

 assistance to the pupa in pushing its way out of the 

 larval burrow preparatory to the emergence of the 

 adult moth. 



SEASONAL HISTORY AND HABITS. 



The complete life cycle of this insect is not known, 

 but it probably occupies only one year in the extreme 

 South, and longer in its northern distribution. The 

 moths emerge usuaUy during May and June, and lay 

 their eggs shortly after their appearance. The larvae 

 upon hatching first attack smaU twigs, in which they 

 tunnel out the center or pithy wood. (Fig. 43.) When 

 the larva has grown too large for the small twig upon 

 which it has been feeding, it crawls out and enters a 

 larger limb. By the early fall the larvas will be found 

 attacking the tree trunks or very large lower branches, 

 in wilich they bore into the hard wood and make 

 their galleries parallel with the grain. At this time 

 and during the spring months the grower can detect . 

 piles of pellets of frass or castings at the base of the trees, and this 

 is a very good way to locate the insect in pecan orchards. The 

 transformation to pupa takes place within the larval gallery during 

 April or May. By means of the sharp toothlike protuberance on 



FIG. 42. The oak or 

 hickory cossid: Lar- 

 va. Enlarged. 



