80 MANUAL OF VEGETABLE-GARDEN INSECTS 



wings arc brownish gray with a nietalhc reflection. Along the 

 front border is a series of short, obUqnc white and dark lines. 

 The hind wings are black with a bronzy reflection ; the fringe 

 is white. The moths appear in late June and early July and 

 lay their eggs during the evening on the recently set pods, 

 depositing from one to three eggs on each pod. The eggs 

 hatch in about two weeks and the young caterpillars imme- 

 diately burrow into the pods. They feed on the developing 

 peas, gnawing out irregular cavities and often webbing them 

 together. The full-grown caterpillar is slightly hairy, about ^ 

 inch in length and yellowish in color, with a black head and 

 brow^iish cervical and anal shields. Affected pods usually 

 ripen prematurely. When the pods open, the caterpillar 

 descends to the ground and spins a silken cocoon a short dis- 

 tance below the surface of the soil. Here the winter is passed 

 either in the larval or pupal state, observers differing as to this 

 point. There is but one generation annually. 



Control. 



In Canada it has been found that both very early and late 

 peas are less liable to injury than mid-season varieties. Pre- 

 liminary experiments indicate that the pest may be held in 

 check by spraying with an arsenical at the time the pods are 

 forming and by two later sprayings at intervals of ten days. It 

 has also been suggested that deep fall plowing of the infested 

 land would destroy many of the hibernating insects in their 

 cocoons. Under ordinary farm conditions in America, the 

 most practical measure is to adopt a crop rotation in which 

 peas do not follow peas. 



References 



Curtis, Farm Insects, pp. 348-350. 18G0. 



Ritzema Bos, Tierisehe Schadlinge und Niitzlinge, pp. 474-475. 1890. 

 Fletcher, Repts. Ent. Canada for 1894, p. 187 ; 1895, p. 138 ; 1897, 

 p. 194 ; 1900, p. 214. 



