54 



ELEMENTARY ENTOMOLOGY 



Nymphs. The little grasshoppers hatch about the middle of May 

 (though we have observed hatching by the middle of March in 

 central Texas) and are of a dusky brown color marked with yellow. 

 The head and legs are the most prominent features of the young 

 nymph. During their subsequent growth they molt five times, at 

 intervals of from ten days to two weeks, the relative size and appear- 

 ance of the different stages being shown in Figs. 66, 68. Professor 

 H. A. Morgan, who made a careful study of an outbreak of this 



species in Mississippi in 

 1900, has given an inter- 

 esting account of their 

 growth and habits, from 

 which the following is 

 quoted : 



Growth. The young on first 

 emerging from the eggs are 

 sordid white and after an airing 

 of an hour or two are darker, 

 assuming a color not unlike the 

 dark gray alluvial soil over 

 which they feed. There are 

 changes of color as the earlier 

 stages are assumed, but until 

 the close of the third stage these 

 changes are not readily percep- 

 tible in the field to the naked eye. 

 At the close of stage four the 

 greenish-yellow color becomes 

 prominent on many forms, and 



in stage five the greenish-yellow and yellow ground colors predominate. The 

 vigorous feeding and rapid growth of the young in stages four and five, and 

 the prominence of the wing- pads in stage five, cause the grasshoppers in 

 these conditions to appear almost as conspicuous as adults. 



Habits. The habits of the young are interesting, and a knowledge of some 

 of them may be helpful in developing remedies. After hatching they remain 

 for several hours in close proximity to the egg pod from which they emerged. 

 With this period of faint-heartedness over they may venture out for a few yards 

 each day into the grass, weeds, or crop neighboring the egg area. Upon being 

 disturbed they invariably make the effort to hop in the direction of their so- 

 called nest. Nymphs emerging from eggs on a ditch bank, if forced into the 

 water will seldom make the effort to reach the other side, but will turn back to 

 the bank from which they were driven. As development takes place the extent 



FIG. 68. Last two stages of nymphs of differ- 

 ential locust. (Enlarged) 



