1903] MORRILL : — ALE YRODES 8 I 



These observations lead to the conclusion that, for this species at least, our 

 winters are so cold as to destroy all stages except the o.g'g. If those species whose 

 food plants are deciduous also pass the winter in the ^^g stage, it would seem 

 necessary, from our knowledge of the habits of the young larvae of Aleyrodes 

 that the eggs be laid on or near the leaf buds, and even then the larvae would 

 have but a slight chance of reaching maturity. 



On the other hand the multiplication of Aleyrodes seems to be favored by 

 parthenogenesis. I have thus far discovered this method of reproduction only in 

 A. vaporariorn7?i^ but it probably occurs in many if not all other species of the genus. 

 Correlated with this, I have found female Aleyrodes to be much more abundant 

 than the males. Out of eight5'-five adults taken at random, representing four 

 different species, I found but twenty males to sixty-five females, and these figures 

 probably represent about the usual proportion of the sexes in nature. 



In regard to the length of life of the adult, and the number of eggs laid by 

 each female, I can only state that in one instance a female of A. vaporarioriim lived 

 in the adult condition twenty-five days, and laid a few more than forty-five eggs. 



I have here briefly considered only a few of the biological problems connected 

 with this interesting group of insects. Very few observations have thus far been 

 made in this direction and until the appearance of Quaintance's admirable paper, 

 the group was much neglected systematically. During the summer of 1902 at 

 Amherst, Mass., I found the five species of Aleyrodes mentioned below, but 

 others — both known and unknown — undoubtedly occur in this region. It is the 

 hope of the writer that this paper may lead to the recording of such by other work- 

 ers in entomology. 



I. Aleyrodes mori maculata, subsp. nov. 



Pupa case. Shiny black, elliptical; length, .•j2-.']6 mm., width, .48-.54 mm. A copious 

 white cottony fringe all around, continuous proximally, but ragged distallj'. "On dorsum 

 of both mesothorax and metathorax near dorsi-meson is a pair of small brown setae ; also a 

 pair of setae near vasiform orifice and on caudal margin of case. . . . There is a pair of 

 minute setae on the margin of case, one on each side near caudo-lateral region. On fourth 

 abdominal segment on each side there is a group of from four to six minute pores. One or 

 two pores are sometimes present on fifth segment on each side, just caudad of those on 

 fourth." — Quaintance {A. mori). 



Adult. Fore wings marked with red and brownish black. Body with conspicuous 

 blackish markings as follows : a transverse band .across front of head, between bases of 

 antennae; a more or less distinct dark spot on each side just above the eye; a roundish black 

 spot on each side of prothorax just below the dorsum; a more or less elliptical black spot 

 covering a nearly equal area on each side of mesothorax, in front of and below the insertion 

 of fore wings, — these last two pairs of spots together occupying a space on each side of the 

 body about equal in size to one of the dumb-bell shaped compound eyes; an elongated spot on 

 dorsum of mesothorax on each side in front of insertion of fore wing — these spots are 



