36 



the Division of Agrostology. Large colonies were at work on pleasant 

 sunny days in January, 1900. Many winged individuals occurred at 

 this time and living specimens were in fact to be found all winter, 

 having been last seen March 2i or up to the time of going to press. 

 Unfortunately, winged individuals were not preserved, and a specific 

 determination can not at present be made. 



NATURAL ENEMIES. 



In spite of the numbers of insects of parasitic and predaceous habits 

 observed by Mr. Johnson and noticed in his article, it was patent to all 



-^7 



Fig. 9.—Xectarophora destructor: a, winged female; b, same from side with wings folded in natural 

 position when feeding; c, apterous female; d, nymph in last stage: e , third joint of antenna of 

 winged form — a-d, much enlarged, e, more highly magnified (original) . 



who had the species under observation that few of these had any very 

 perceptible effect upon lessening the immense numbers of their host 

 last year. 



From Dr. Fletcher we received October IT some parasites of this 

 species which were identified by Mr. Ashmead as Praon cerasaphisYitch, 

 Aphidins fletcJieri Ashm. MS., and Isocratus mdgaris Walk. 



A list of Syrphus fly, ladybird beetle, and other natural enemies of 

 this species has already been furnished by Professor Johnson in his 

 article previously referred to and need not receive further attention 

 here. From the abundance of some of these natural enemies Professor 

 Johnson has expressed the opinion that the insect will not again be so 

 injurious in many years as was the case the past season. In the vicin- 

 ity of the District of Columbia none of the natural enemies were at all 



