158 DJi. A. D. IMMS ON THE 



spread over a flat open vessel. If tobacco smoke be puffed over the sweepings, 

 any larvae present may sooner or later be detected moving about. 



The most active period of larval life is during the hot weather and subsequent 

 " rains." At the end of the latter the greater part of growth has taken place. During 

 the Indian cold-weather season they are much less active, seldom move unless disturbed, 

 and only occasionally feed on the Psocids when presented before them. Nearly full- 

 grown larvae were met witli as early as July 25th, eight months further having to elapse 

 before they pupated. On the other hand, a larva measuring only 3'6 mm. long was found 

 as late as March 6th — less than a fortnight before they usually commence spinning the 

 occoon. Possibly in some instances the life-history may occupy a second year. Owing 

 to my absence from Allahabad this larva died and I was unable to determine the 

 accuracy of this suggestion. 



5. The Pupa. 



Towards the middle of March the larvae become full-fed and commence to form their 

 cocoons. The latter are nearly spherical in form, and are composed of fine particles of 

 dust or sand loosely bound together by means of silk (PL 32. fig. 6). The cocoon resembles 

 its surroundings very closely, and even when found in captivity in vessels containing only 

 a small quantity of sand and dust it is not easy to discover. On opening a cocoon its 

 interior is seen to be white and smooth, being lined with silken threads closely woven 

 together. The average size of the cocoons taken from several specimens is 5 mm. long 

 and 3 mm. across. 



The larva after spinning up remains in a resting condition for about fourteen days. 

 It is curved upon itself with the head bent towards the ventral side of the body, becomes 

 whitish in colour, and unless disturbed betrays no signs of movement. By about the 

 tenth day after spinning the cocoon, the trunk-region of the larva became darker in 

 colour and much swollen, the head and neck appeared as dead and empty husks, and, 

 moreover, the animal exhibited no movement. By the thirteenth day the larval cuticle 

 ruptured and the pupal appendages appeared externally. 



The pupa measures 3 mm. in length, 1*8 mm. wide across the head, and 2*25 mm. 

 in maximum width. It is markedly flexed towards its ventral surface, and all 

 the imaginal appendages are clearly visible and enclosed in sheaths that are external in 

 position (fig. 7). The sheaths of the fore wings extend backwards to about two-thirds 

 the length of the abdomen. The extremely elongated hind wings are enclosed in sheaths 

 that are coiled on themselves after the manner of a watch-spring (figs. 7 & 8). They 

 cross one another towards their bases, close to the hinder extremity of the abdomen, so 

 that the right wing-case crosses the left one and comes to lie on the left side, while the 

 left wing-case passes over to the right side (fig. S). By this means they are conveniently 

 stored away in a compact manner so as to occupy a very small space. The head is 

 separated from the thorax by a narrow flexible neck derived from the first segment of 

 the neck in the larva. The labrurn and frontal region of the head are but little produced 

 in the pupa, and totally different from the elongate shape they assume in the perfect 

 insect. The maxilloe and their palpi project freely forwards for a long distance in front 



