82 



The Rocky Mountain Locust. 



time after extrication they show the effects of this severe 

 bending by their curved appearance. 



The molting, from the bursting of the pupa-skin to the 

 full adjustment of the wings and straightening of the legs 

 of the perfect insect, occupies less than three-quarters of 

 an hour, and sometimes but half an hour. It takes place 

 most frequently during the warmer hours of the morning, 

 and within an hour after the wings are once in position 

 the parts have become sufficiently dry and stiffened to en- 

 able the insect to move about with ease, and in another 

 hour, with appetite sharpened by long fast, it joins its 

 voracious comrades and tries its new jaws. The molting 

 period, especially the last, is a very critical one, and dur- 

 ing the helplessness that belongs to it the unfortunate 

 locust falls a prey to many enemies which otherwise would 

 not molest it, and not infrequently to the voracity of the 

 more active individuals of its own species. 



As already stated, there are five molts exclusive of that 

 which takes place upon leaving the egg. In the first stage 

 — that following the egg — the wing-pads are not visible ; 

 in the second stage they are likewise scarcely noticeable ; 

 in the third (after the second molt) they project but little 

 beyond the meso- and meta-thorax, differ but little in size, 

 and are directed downwards, lying separately close to the 

 body ; in the fourth stage (after third molt) they are di- 

 rected upward, the hind covering and hiding more or less 

 the front pair, and the joints bearing them retreating more 

 beneath the prothorax ; in the fifth stage (after fourth 

 molt) they are enlarged as seen in the pupa, and with the 

 fifth molt the sixth or perfect stage is attained. 



European authors differ as to whether there are three, 

 four or five molts in the European migratory species ; * 



* See Koeppen, " Ueber die Heuschrecken in Suedrussland." 1865. pp. 22-3. 



