THE GREEN-STRIPED LOCUST: ITS NATURAT, HISTORY. 



193 



FlG.56 .— Caloptknus SPRETUS: a, a. newly- 

 hatohed \ar\x ; b, full grown larva ; c, the pupa. 



this species. Two or three weeks later, another deposit of eggs is made 

 iu the same manner, and a third, and perhaps a fourth, at intervals 

 thereafter.* The eggs hatch in about three weeks, and produce the 

 forms mentioned by Dr. Harris as occurring " in various states of ma- 

 turity, in pastures and mowing lands, from the first of June to the- middle 

 of August," in the New England States. 



After leaving the egg, the insect undergoes at intervals two meltings 

 without showing the vi'ing-pads that are later developed. These are 



known as the three larval stages. An- 

 other molt brings it to its first pupal 

 stage, in which the small wing-pads are 

 in position, turned upward over the 

 back. The fourth molt develops the 

 fifth stage, or the true pupa in which 

 the wing-pads attain their greatest de- 

 velopment and the thorax has assumed 

 nearly the form of that of the mature insect. W'ith the fifth molting 

 the mature, winged insect appears. Fig. 56 represents the larv^x at dif- 

 ferent stages and the true pupa of the Rocky mountain locust. 



The moUiyig operation. — The moltings of insects are so wonderful, 

 and so little understood, and those of the grasshoppers are so very 

 rarely seen — not once where a thousand are observed of the butterflies 

 and moths — that I borrow the excellent illustrations and explanations 

 of Prof. Riley of the final molting of the Rocky mountain locust, from 

 the I St volume of the Report of the U. S. Entomological Commission. 

 Those who have not access to this volume, or who, among so much 

 other highly interesting material, may have overlooked this portion, will 

 be grateful for this reproduction: 



When about to acquire wings, the pupa crawls up some post, weed, 

 grass-stalk or other object, and clutches such object securely with its 

 hind feet, which are drawn up under the body. In doing so, the favor- 

 ite position is with the head downward, though this is by no means 

 essential. Remaining motionless in this position for several hours, with 

 antennae drawn down over the face, and the whole aspect betokening 

 heli)lessness, the thorax, especially between the wing-pads, is noticed to 

 swell. Presently the skin along this swollen portion splits right along 

 the middle of the head and thorax, starting by a transverse curved 

 suture between the eyes and ending at the base of the abdomen. 



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

 splitting, and when it presents the appearance of a in Fig. 57. As soon 



*Caloptenus femur-ruhrum has been observed by Prof. Rile}^ to deposit four "egg-pods," 

 averaging one hundred and four eggs each, within a period of sixty days, giving an egg- 

 laying period for the species of about two months. 

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