344 NATURE SKETCHES IX TEMPERATE AMERICA 



attracting the pretty male of the sprinkled locust, Chloealtis 

 conspersa, and in a moment he also joined in the jollification. I 

 have witnessed many of these manoeuvres, where only the males 

 were present, the females taking no part in the play whatever. 

 The performances always occur in the heat of the sun, and the 

 hotter the day, the greater the activity displayed by the locusts. 

 There seems no doubt but that these acridians have a culti- 

 vated ear for grasshopper music aside from its mere secondary 

 sexual attraction. 



In the plate photographic illustration, the upper figure 

 shows the male with spread wings; the lower figure portraying 

 the female. It will be seen that the coloration of the wings of 

 this locust is quite similar to that in the wings of the butterfly, 

 Eurane.ssa antiopa. It has been suggested that herein lies a 

 case of mimicry; the locust mimicking the butterfly for pro- 

 tection, but I have not been able to trace any connection of 

 this character between these two insects. It is more likely 

 that the similarity in color is a mere coincidence. 



The Carolina locust lays her eggs in the ground in September, 

 one to .several males often awaiting clo.se by while she is thus 

 occupied. The eggs remain in the ground through the winter, 

 and hatch in the following spring. The young seem to undergo 

 five instars, or moults, before they mature the following summer, 

 in July and August. In an effort to determine whether this 

 locust changes color at the critical stage of the last moult to 

 resemble the ground iipon which it lives. I tried a number of 

 experiments. A few of these, with the resulting conclusions, 

 are given herewith: 



On July twenty-ninth, I subjected two nymphs, one rust- 

 red, the other gray-speckled over the body, to a residence within 

 a screen -covered vivarium. On the bottom of the enclosure 

 to one side was placed a layer of light .sand, and on the other 

 side, separated by a .screen partition, was a covering of dark 

 earth. The rust-red form was placed in the side containing the 

 light sand, and the gray-speckled form on the dark earth. 



These in.sects had been confined here but a few hours before 

 they started to moult. At 10.15 a.m., of the same day, the red 

 form, after climbing on the vertical screen partition, com- 

 menced to moult, and by 10.45 a.m. had entirely emerged from 



