23 



ers of their beneficial attack upon eggs it may be that our cage con- 

 ditions were not suitable for aggressive work of this mite. The 

 numbers to be found were very assuring and this mite must be recog- 

 nized as an important enenr^ to grasshoppers. 

 The larva? of a species of Carabid beetle, which we were unable to 



<5>r 3 y c " d 



Fig. 7. — Trombidium locustarum : a, mature larva when about to leave the wing of a locust; b, pupa; 

 c, male adult when just from the pupa; d, female — the natural size indicated to the right; e, palpal 

 claw and thumb; /, pedal claws; g, one of the barbed hairs; h, the striations on the larval skin 

 (from Riley). 



rear to the adult condition, were also found to be an energetic feeder 

 upon eggs. With their large mandibles they were observed breaking 

 the egg sacs and devouring the contents. 



During April, May, and June the ash and black colored blister 

 beetle (Macrobasis unicolor) (see fig. 8) showed by its numbers and the 

 manner of the attack of the young to be an 

 important enemy of grasshopper eggs. In 

 sweeping they were a common capture, and 

 in following the plows and cultivators the 

 pseudo pupa? (coarctate) were seen in great 

 numbers. The young of the first and second 

 stages were also found among the egg-pods. 



Of the true parasitic forms two species 

 were bred, Scelio hyalinipennis Ashm. and 

 Scelio oedipodce Ashm. While the former 

 species appeared earlier than the latter, both 

 continued to emerge as adults irregularly 

 from May 1 until the latter part of June. 

 They were found to come in the majority 

 of cases from the eggs of the lower end of 

 the pod, and in a few instances this was found the case even where 

 grasshoppers were coming from the upper ends. As a rule not all of 

 the eggs of the pods are parasitized, and the inference is that the habit 

 of the parasites to attack the deeper placed eggs is to so retard the 

 development of the offspring as to guarantee food for the broods that 



Fig. 8.— Macrobasis unicolor: Fe- 

 male beetle at right, twice nat- 

 ural size; male antenna at left, 

 greatly enlarged (from Chitten- 

 den). 



