184 LJan»a«7» 



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Description of the manner of pupation of Didyopteryx ForsTcaleana, Linn. — On ' 

 lifting up one of the neatly folded-over lobes of the Maple which are met with so 

 frequently during the middle and end of the month of June, we observe underneath 

 it the little yellow larva of this species lying at full length on a coueh of white silk. 

 Supposing we bring it home and watch it closely, we shall notice, about a week 

 afterwards, that its three or four anterior segments become swollen, and, at the 

 same time, that the larva loses all but the faintest power of motion, its ninth 

 segment having an orange tint. After a time the larva is seen to pass slowly into 

 the pupa state, and the whole of its larval skin remains collected in a little heap at 

 the extremity of the abdomen ; the pupa is at first quite white, having the tip of 

 its anal segment covered with a cluster of little brown bristles, which act like so 

 many little anchors, and enable the pupa to obtain a fair hold of the silk contained 

 in its abode. On close inspection, a little brown spot is noticeable on one side of 

 each of the eyes and in the centre, but situate at the bottom of the eyes a little 

 dusky-coloured dot is dimly visible. At the expiration of a few hours we perceive 

 that its head, thorax, and wing-cases turn to a pale amber-yellow, the abdominal 

 segments retaining their original colour ; in the centre of the dorsal surface of the 

 pupa's abdomen a pale orange-coloured blotch has made its appearance, and 

 furthermore the anal segment has a somewhat swollen, glassy look. After an 

 intei-val of two or three days the eyes begin to turn pale brown, afterwards deepening 

 into dark brown, and finally become quite black. After a suitable interval has 

 expired, the head, thorax, and wing-cases become whitish, and the blotch on the 

 dorsal surface of the abdominal segments deepens into a brownish tone. At the 

 next phase of its economy the sides and base of the thorax assume a pale crimson 

 hue, the crimson-coloured pigment spreading itself over the head, thorax, and 

 wings, imparts a similar tint to them, ultimately, however, deepening to pale 

 ochreous. While the immediately preceding part of its economy is taking place, , 

 each wing becomes mapped out (so to speak) by a net-work of little narrow canals, 

 thus imparting to the wings of this little insect its beautifal reticulations ; the 

 decorations of the inner margin of the anterior wings then develope themselves ; in 

 some individuals they are represented by a largish black blotch on each wing, 

 while on others they are seen simply in the form of a thin dark line or two or three 

 little black spots only ; consequently the markin gs on the anterior wings are dependent 

 upon the presence, in more or less quantities, of this black-coloured pigment. The 

 pupa gradually becoming more and more matured, its abdomininal segments are 

 observed to have a yellowish appearance ; a little black dash is noticeable at each side 

 of the basal portion of the pupa's thorax, this and the head having ochreous markings ; 

 the eyes then have changed from black to a dull blneish tint, each having a black 

 central spot ; the markings and colouration of the imago having finally settled 

 down to their proper tone. The pupa, when disturbed, lashes its body about in a 

 state of great alarm, especially so if brought in near contact with a lighted lamp. 

 When sufficiently mature the imago escapes from its puparium, leaving the latter 

 projecting. The puparium in most instances is whitish, at times quite white ; 

 sometimes, however, it is stained with a pale brownish tint. — Id. 



