70 



INSECTS INIURIOL'S lO VKCETARLES 



swarm at any time of the year, and they are the most dreaded 

 of pests, because of the rapidity of their attack, when they lay 

 waste large districts, and even considerable portions of states. 

 The Red-legged Locust (Mclanoplus femur-rubrum DeG.). — 

 This is our commonest North American grasshopper, being 

 found practically everywhere. It is one of the smaller species 

 (fig. 39), and where it is not held in subjection by natural 

 enemies it may become a de- 

 cided nuisance in cultivated 

 lands. It seldom exhibits the 

 migratory tendency, but some- 

 times gathers in swarms and 

 moves in concert, not, however, 

 rising to great heights, but drifting with the wind as do the true 

 migratory species. 



The Rocky Mountain Locust {Mclanoplus sprctns Thomas). 

 — This is the most destructive of all native grasshoppers, and 

 has been the cause of greater losses to agriculture in the past 

 than perhaps all of the other known species of grasshoppers 



Fig 39- — Melanoplus femur-rubrum 

 Natural size. (After Riley) 



Fig. 40.— Reeky Mountain locust, a. a. a. Female ovipositing; b, egg-pod extracted 

 from ground, with end broken open; c. a few eggs lying loose on ground; d. e, 

 earth removed, to illustrate egg-mass in place and one being placed;/, where a mass 

 has been covered up. (After Riley). 



