194 Psyche [December 



The species of ants which have been found locally attending 

 Vanduzea arquata have been determined by Professor Wheeler 

 as follows: Formica obscuriventris Mayr., Formica exsectoides 

 Forel, Camponotus pennsylvanicus DeGeer, Crematogaster lineolata 

 Say, Prenolepis imparis Say. 



Economic Importance. 



Although the immense number of insects, with their attendant 

 feeding and oviposition, would naturally be supposed to affect 

 the host, very little damage, as a matter of fact, seems to result 

 from their existence on the locust. The amount of sap consumed 

 would of course be practically neghgible and the buds seem in 

 no way retarded in their development by the presence of the eggs. 

 The egg-slits are very small and heal very quickly, leaving no 

 wound, and no trace has been found of fungus or of other insects 

 in these incisions. A careful comparison of trees in the field 

 fails to show that those harboring this species of Membracidse 

 are in any way less sturdy than those on which the insects are 

 not found. These facts have led to the conclusion that the 

 economic importance of the insect is hardly to be considered. 



Technical Descriptions. 



Egg. 



Measurements: Length 1.4 mm.; maximum width .3 mm. 



Smooth, without sculpturing; white; club-shaped; neck gradually acute, very 

 slightly grooved; micropyle oval, opening tangential to longitudinal axis; base 

 smooth, rounded; chorion white translucent; cap small, subcylindrical. 



First Instar. 



Measurements: Length 1.2 mm.; maximum width .25 mm. 



Very light grayish-brown with top of head and line down median dorsum white; 

 six longitudinal rows of long, white bristly hairs, two rows down dorsum and two 

 rows on each side; abdomen upraised; entire body noticeably long in proportion 

 to its width. 



Head broad, gray-brown in front, white and produced above, covered with white 

 bristly hairs, top of head bidentate; eyes reddish; ocelli not \asible; antennre scarcely 

 visible; clypeus set o£E by distinct white suture. Thorax brown with broad, white, 

 median dorsal band; segments distinct and subequal; each segment with a stiff, 

 white bristly hair on each side dorsal line and two lateral bristles on each side, 

 one below the other. Abdomen brown on lateral areas, white on dorsal line, under 

 surface white; eight distinct segments each armed with a pair of long bristles above 

 and two single bristles on each side; first abdominal segment short, eighth long, 

 others equal in length; anal tube long, dark colored, evaginated; tip of abdomen 



