N0.13G2. AtEYRODIDS OF CALIFORNIA— BEMIS. 475 



more or less covered with wax; they are elliptical in shape and cuin cd 

 to a greater or less degree. At first they are white or pale yellow^, 

 but as the em])ryo develops the color becomes darker; the young 

 hatch ill about ten to thirteen days, the egg opening along the inner 

 curve from the apex toward the base. The pedicel, which is such a 

 noticeable feature of the eggs of the Aleyrodidie, is a prolongation of 

 the chorion, and can be seen within the body of the gravid female, 

 frecjuently attracting attention by its dark brown color. 



The embryo lies with its hi^ad toward the apex of the shell, and 

 about the sixth day after ])eing laid the reddish eyespots and orange- 

 colored visceral mass ])egin to show plainly. In the <igg^ under 

 observation there elapsed from forty-two minutes to three hours and 

 eight minutes from the time that the shell began to open till the larva 

 was free. The e^y^g that took the greater time was upon dry material 

 and was dark l)rown in color, the shell when empty kee])iiig its 

 upright position and shape, so that the slow hatching was probably 

 due to the toughness of the chorion. As soon as hatched the young 

 larva moved freely about on the leaf, but never went more than an 

 inch from its shell and to this habit it is doubtless due that the emptj' 

 shell is so often found clos(> to the pupa-case. Specimens were seen 

 active for eight or more hours. One lived for fifty-three hours and 

 died without attaching itself. This may have been because the leaf was 

 withering, although when removed to another it did not atfix itself. 



At first the lar^';e are very convex and entirely free from secretion 

 of any kind, but within an hour after emerging from the Qgg the 

 beginning of the marginal ))aiid of wax is seen. When the food was 

 allowed to dry somewhat so that it wilted, the young larvte secreted a 

 coating of wax, which was not present under other circumstances. 



The author has not l)een able to determine the time Avhich elapsed 

 before the first molt or between the successive molts. From the 

 fact that the larval exuviiv are alwa3's on the dorsum of the succeed- 

 ing stage, and that they are folded back with the cephalic portion of 

 the ventral surface uppermost, it is almost certain that the skin breaks 

 on the ventral surface or along lateral margins. This is the reverse 

 of the mode in the pupal stage, where the imago issues through a rent 

 made along the longi-dorso-medial and thoi-aco-abdominal sutures, the 

 flaps being folded back. When a parasite emerges from a pupa-case 

 there is left an irregular round hole in the dorsum ot the thorax and 

 cephalic region; this characteristic opening makes it possible to deter- 

 mine the extent of parasitization among the empty cases. The mmi- 

 ber of larval stages has been determined from the molts, which are 

 uniforndy found upon the dorsum of the pupa-cases. 



In the first stage the larva? are always semitransparent, with 

 functional legs and anteniuw and in the majority of species have from 

 seven to nine latero-margiiial hairs. After the lirst molt the cuticle may 

 begin to grow darker in color ainl thicker in texture, until the culmi- 



