io8 



AN INTRODUCTION TO ENTOMOLOGY. 



look under that head in the older works for descriptions of them.* 

 The following table will aid in determining the males of the species 

 mentioned below ; as a rule there will be but little, if any, trouble 

 in assorting the females after the males are determined. 



A. Apex of last abdominal segment of male distinctly notched. 

 B. Length of body to tip of wing-covers 29-35 mm - (1. 16— 1.4 inches). 



M. SPRETUS. 



BB. Length of body to tip of wing-covers 23-26 mm. (0.9-1.04 inches). 



M. ATLANTIS. 



AA. Apex of last abdominal segment of male entire or most obscurely notched. 

 B. Anal cerci enlarged at apex. M. FEMORATUS. 



BB. Anal cerci tapering. 



C. Species of medium size ; anal cerci much narrowed, but without a notch. 



M. FEMUR-RUBRUM. 



CC. Species of large size ; anal cerci suddenly narrowed, making a prom- 

 inent right-angled notch on lower side. M. differentials. 



The Rocky Mountain Locust or Western Grasshopper, Melanoplus 

 spretus. — The most terrible of insect scourges that this country has 

 known have been the invasions of this species. Large areas of 



Fig. 07.— Egg-laying of the Rocky Mountain Locust, a, a, a, female in different positions, oviposit- 

 ing ; b, egg-pod extracted from the ground, with the end broken open ; c, a few eggs lying loose 

 on the ground ; de shows the earth partially removed, to illustrate an egg-mass already in place, 

 and one being placed ; /"shows where such a mass has been covered up. (From RUey.) 



country have been devastated, and the inhabitants reduced to a 

 state of starvation. The cause of all this suffering is not a large 

 insect. It is represented natural size by Fig. 97. It measures to 



* For a statement of the reasons for the adoption of the name Melanoplus, see 

 paper by S. H. Scudder, Proc. Boston Soc. Nat. Hist., Vol. XIX. p. 261. 



