[88] REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



down June 22, at 4 p. m. They remained over night, and left the 23d, without doing 

 any harm. 



i attempted to raise a colony of locusts in the garden, but after the second molt a 

 cold rain killed every one. 



The native, locusts are unusually scarce this summer. I have not observed a single 

 specimen of C. femur-ruhrum with, vrings. Only a few specimens of C. Mvittatus have 

 been seen, and other species are scarcely more abundant. 



DEPOSITION OF EGGS. 



The invading swarms of locusts in the fall did not deposit eggs in loose, freshly- 

 stirred soil. The locations most generally chosen for this purpose were those in which 

 the soil was bare, and had become somewhat compact. Along the streams, x)reference 

 was given to the south side next to the timber, and especially to the northward bends. 

 On the high prairies, situations having a southern exposure were selected. Very few 

 eggs were deposited in the prairie sod, unless so closely grazed by stock as to be almost 

 bare. Roadsides, yards, and all situations where the soil is bare and sufficiently com- 

 pact, are the favorite places of deposit, and more especially so if they have a warm 

 southern exposure. 



EGG PARASITES. 



We derived a benefit by no means small or inconsiderable from the workings of 

 small, unnoticed insects feeding upon the eggs. In some situations near Manhattan, 

 the egg-feeding larvae of different kinds destroyed from 15 to 20 per cent, of the eggs. 



Several species of Carabid larvsB were found to devour the eggs, generally destroy- 

 ing only a i)ortion of those in each pod, but attacking many. 



Two or three species of Dipterous larvae were found feeding upon the eggs. From 

 two or three to six or more of these were found within each egg-pod attacked, which 

 was soon reduced to a mass of empty shells. 



A species of Hymenopterous larva was found in considerable numbers preying upon 

 the eggs. This insect was always found feeding within the pod, or in the soil near the 

 ruins of its late abode. 



The larvsB of what Prof. Riley afterward proved to be a Blister Beetle (Lytta 

 cinerea) also destroyed large numbers of the eggs. This insect entered the egg-pod, 

 feeding upon its contents until the whole was destroyed. 



HATCHING. 



The locusts commenced hatching in the vicinity of Manhattan about the 6th of 

 April. Very few could then be found, and it was only in the most favorable situations 

 that any had hatched. A species of leaf -hopper ( Tettigonidw), which somewhat resem- 

 bles the young locust in size and hopping movements, and which makes its appearance 

 very early in the spring, was mistaken by many for the newly hatched locusts. This 

 gave rise to reports of hatching two or three weeks before any locusts had really ap- 

 peared. By the 15th of the month, the hatching had increased, though yet confined 

 to situations most exposed to the warm sunlight. During the latter part of the month, 

 hatching was much retarded by cold rains. On the night of the 29th, a heavy frost 

 occurred, forming a crust upon the ground a half inch in thickness The next day 

 was very warm, and hatching commenced as soon as the frost was out of the ground. 



The young locusts as they hatched sought shelter through the night and during rains 

 in grass and under leaves. There was a gradual disappearance of their number about 

 as fast as hatched, but none could be found dead. But little vegetation had yet ap- 

 peared, especially upon their hatching- grounds, and the temperature was generally so 

 low that they moved but little, not appearing to leave their hatching-ground in search 

 of food. 



On the 1st of May, in a few exceptional spots of ground, nearly 90 per cent, of 

 the eggs were hatched. Generally, however, not more than 15 per cent, had devel- 

 oped, and in cool, damp places hatching had scarcely .commenced. The locusts issued 

 more numerously on the 1st and 2d than they had hitherto done. May 3, the weather 

 was very cool, and those already issued were inactive, scarcely moving from their 

 place of concealment when disturbed. At first the locusts hatched and developed 

 slowly, and great numbers were evidently destroyed by the cold and rains. Though 

 the hatching had continued, with but few interruptions, from April 6, they were not 

 by May 3 so numerous as at some time previous. 



Hatching continued slowly to increase until the 10th to the 15th, when the earth seemed 

 springing into life. No description can give an idea of the immense numbers which 

 issued each day. The ground in some places appeared nearly white, from the little 

 white pellicles thrown off by the hatching insects. The locusts always issued in great- 



