Strawberry and Grkenhouse Pests. 



175 



so-called "pupa" stage when tliey greatly resemble scale insects, as 

 shown at C and D, figure 45, and ^, figure 40. In a few days the 

 skin splits o[)en and the minute, four-winged adult emerges, as 

 shown at fin figure 46. Thus the whole life cycle may 1)e passed 

 through in four or five weeks, so that three or more broods of these 

 " white-flies " may work on the strawberries during the growing 

 season. The jstravvberry leaves sent us were nearly covered on the 



4(3.— Aleprodes dtri R. and H. a, orange leaf badly infested by full-grown nymi^hs 

 or ''larvoi;'' b, outline of egg; c, nymph hatcliing from egg ; d, newly - 

 hatched nymjih, ventral view ; e, adult female insect; f, adult icith wings 

 still unfolded emerging from nymph or "ptqm" skin; g, advanced nymph 

 or 'picjm." All m,uch enlarged except a. {After Riley and Howard.) 



under side with the scale-like nymphs of these interesting ci;eatures, 

 which are very closely related to the scale-insects and the plant- lice. 

 Most, if not all, of the injury is done by the nymphs, which suck 

 their liquid food or sap from the interior of the plant. They work 



