366 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



Life History. Fhu life history has nut been followed for the 

 whole season, but all of the stages have been observed. Moths 

 of what seemed to be the first summer generation were obtained 

 in late July. The eggs arc about one-twenty-fifth an inch 

 in diameter, oval, and of a grayish color, turning pinkish in a 

 day or two. They are laid singly, usually in the " bud " of the 

 turnip or cabbage. With a temperature of 80 F. they hatched 

 in three days. The caterpillars become full grown in about 

 eighteen days, and then spin thin cocoons between the leaves 

 in which they transform to pupa?. The pupal stage requires 

 but about a week in midsummer, so that the moths emerge just 

 about a month after the eggs were laid. The most serious injury 

 seems to occur in late summer, particularly to young fall cabbage 

 and turnips. 



Control. Use the same measures as advocated for the imported 

 cabbage worm and the cabbage looper. 



The Diamond-back Moth * 



The larva of the imported diamond-back moth or cabbage 

 plutella are commonly found on cabbage wherever it is grown, 

 and as a rule do but little injury, though occasionally they 

 become troublesome. 



" The larva when full grown measures three-tenths inch in 

 length, tapers a little to the extremities, and is of a pale green 

 color. It is active and irritable, in this respect being very 

 different from any of the larger Iarva3 described." The wings 

 of the parent moth " are kept folded against the sides of the body, 

 are a little turned up at the tips, and are provided with a long 

 fringe. The color above on the head, thorax, and upper part 

 of the closed wings is a light clay-yellow. That part of the 

 wings that is lowest when they are folded is bronzy brown, this 

 color terminating abruptly where it meets the clay-yellow of 

 the back by a well-defined sinuous margin. The length from 



* Plutella maculipennis Curtis. Family Tineidae. 



