40 



SIXTU ANNUAL REPORT 



In the ^reat majority of insects the wings in the pupa are simply 

 compressed and thickened without being folded, and in the imago 

 they expand without material change in form. Those of our Phyllox- 

 era are rolled up both from the sides and the end, and, in expanding, 

 they unroll in the manner designated at Figure 7, d, <?, /'—the whole 

 operation requiring but about five minutes. At first, and for some 

 time after the molt, the color of the body of the new fledged Phyllox- 

 era is of a uniform bright, deep yellow, with the wings white and 

 rather opaque, and the eyes brown. The dark thoracic band and mere 

 diaphanous and smoky nature of the wings are gradually acquired in 

 the course of a day, and the insect finally presents the appearance of 

 Figure 6, ^, li. The wings when highly magnified are seen to be thickly 

 covered with minute hooks (Fig. 8, /'). 



These winged insects are most abundant in August and Septem- 

 ber, but may be found as early as the first of July, and until the vine& 

 cease growing in the fall. The majority of them are females, with the 

 abdomen large, and more or less elongate. The veins of the front 

 wing are not connected (Fig. 7, r/), and, by virtue of the large abdo- 

 men, the body appears somewhat constricted behind the thorax. From 

 two to five eggs may invariably be found in the abdomen of these.^ 

 and are easily seen when the insect is held between the light, or 

 mounted in balsam or glycerine. A certain proportion have an en- 

 f^'-- "J tirely dilferent shaped and 



smaller body, the abdomen be- 

 ing short, contracted, and ter- 

 minating in a fleshy and dus- 

 ky penis-like protuberance; 

 the limbs stouter, and the 

 wings proportionally larger 

 and stouter, with their veins 

 connecting (Fig. 7, h). This shorter form (Fig. 8, ^') never has eggs 

 in the abdomen, but, instead, a number of vesicles (Fig.8, e), contain- 

 ing granulations in sacs. These granulations have much tiie appear- 

 ance of spermatozoa, and seem to have a Brownian movement, but 

 are without tails. 



This form has been looked upon as the male by myself, Planchon,. 

 Lichtenstein and others. Yet I have never succeeded in witnessing 

 it performing the functions of a male, nor has any one else that I am 

 aware of. The males in all plant-lice are quite rare, and, in the great 

 majority of species, unknown. Where known, this sex bears about 

 the same relation to the female as the shorter and smaller Phylloxera 

 just described does to the larger. These same differences observed in 



I'TEHooosTif CiiAKACTEii-;: — fl, ft, (Uflfieiit Aenatioii <il 

 fVcmt-wiiif;-; c, hiiKl-wing'; f/, <',./', ^-h()^vil1i^ ilevfloii- 

 iiifiit of wings. 



