October, '10] GILLETTE: PLANT LOUSE NOTES 403 



usual place of entry is where two oranges are in contact or an orange 

 and leaf are in contact. 



The full grown larva is about Y2 inch long. The color varies from 

 greenish white to dark gray, with broken irregular stripes more dis- 

 tinct in the darker specimens. During the growing period of the 

 larva it remains almost continuously within the fruit, but upon 

 reaching maturity it wanders about over the cage at night. During 

 the day it is always found in its burrow. This traveling about off the 

 fruit is no doubt for the purpose of finding a suitable place for pupa- 

 tion. In case no favorable location is found it will pupate within its 

 burrow, first making a slight irregular cocoon. Pupation within the 

 burrow is in fact, very common, though other places may be selected 

 if available. The total length of the larval hfe is from 55 to 60 days 

 and the pupal period from 9 to 12 days in midsummer. 



The number of broods in a season is not very well defined and there 

 is more or less overlapping. There does appear, however, to be a 

 period in the spring when the moths are abundant, and again in the 

 early fall. Moths were common in May and the first part of June and 

 practically none seen in July and August, Moths appear again in 

 September and possibly also again about December. Judging from 

 the appearance of the worms and of the moths there is probably 

 three generations, or two with a partial third generation. 



Two species of Braconids (species not yet determined) have been 

 reared from the larva. As for control measures, spraying with an 

 arsenical has been suggested, but the worms would have to become 

 more abundant than they have thus far to make this practical. The 

 most feasible measure seems to be the picking up and destroying of 

 dropped fruit in the field, while the larva is still within its burrow, 

 and also the destruction of the wormy culls as they are sorted out in 

 the packing house. 



PLANT LOUSE NOTES, FAMILY APHIDID^ 



(Continued), Plate 26 ' 



By C. P. Gillette 

 Aphidini 



Aphis salicicola Thos., Figs. 1 and 2. Taken at Geneva, Albany, 

 Webster and Woods Holl, on willow. I also have specimens from 

 Massachusetts taken on wallow by Dr. T. H. Morgan. 



The long cyhndrical cornicles, the single row of about 7 sensoria 

 on third joint of antenna, and the very short second fork of the cubital 

 vein seem to be the important distinguishing characters of this species. 



