282 RErORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



"Let us now imagine that we are watching one from the moment of this 

 splitting, and when it presents the appearance of Fig. 20, a. As soon 

 as the skin is split, the soft and white fore body and head swell and 

 gradually extrude more and more by a series of muscular contortions; 

 the new head slowly emerges from the old skin^ which, with its empty 

 eyes, is worked back beneath, and the new feelers and legs are being 

 drawn from their casings and the future wings from their sheaths. At 

 the end of six or seven minutes our locust — no longer pupa and not yet 



1 



Fig. 20. — Rocky Mountain Locust.— Process of acquiring- wings; a. pnpa witli skin jnst split on the 

 back; b, the imago extruding; c, the imago nearly out; d, the imago with wings expanded; e, the 

 imago with all parts perfect. (After Eiley.) 



imago — looks as in Fig. 20, h, the four front pupa-legs being generally 

 detached and the insect hanging by the hooks of the hind feet, which 

 were anchored while yet it had that command over them which it has 

 now lost. The receding skin is transparent and loosened, especially 

 from the extremities. In six or seven minutes more of arduous labor — of 

 swelling and contracting — with an occasional brief respite, the antennae 

 and the four front legs are freed, and the fulled and crimped wings 

 extricated. The soft front legs rapidly stiffen, and, holding to its sup- 

 port as well as may be with these, the nascent locust employs whatever 

 muscular force it is capable of to draw out the end of the abdomen and 

 its long hind legs (Fig. 20, c). This in a few more minutes it finally does 

 and with gait as unsteady as that of a new-dropped colt, it turns round 

 and clambers up the side of the shrunken, cast-off skin, and there rests 

 while the wings expand and every part of the body hardens and gains 

 strength — the crooked limbs straightening and the wings unfolding and 

 expanding like the petals of some pale flower. The front wings are at 

 first rolled longitudinally to a pointy and as they expand and unroll, the 

 hind wings, which are tucked and gathered along the veins, at first curl 

 over them. In ten or fifteen minutes from the time of extrication these 

 wings are fully expanded and hang down like dampened rags (Fig. 20, d). 

 From this point on the broad hind wings begin to fold up like fans 

 beneath the narrower front ones, and in another ten minutes they have 

 assumed the normal attitude of rest. Meanwhile the pale colors which 

 always belong to the insect while molting have been gradually giving 

 way to the natural tints, and at this stage our new-fledged locust presents 



