538 BRITISH LEPIDOPTERA. 



broods may be found on their webs at all times. Boisduval notes 

 (Bull. Soc. Ent. France, 1851, p. lxl) the damage done by the larvae of 

 this species in Poitiers. 



Larva. — The newly hatched larva (May 13th, 1896) has a very large 

 black and shiny head, which forms roughly a tall trapezoid in shape, 

 with scattered hairs over it. The body is dark brown in colour, and 

 tapers gradually towards the anus. The scutellum smooth. The 

 ear-like tubercles on the 1st thoracic segment strongly developed, 

 and also the hairs arising from them. The dorsal tubercles form 

 chitinous warts, are arranged in trapezoidal form, and bear minutely 

 thorny or serrated hairs. Of these i is, however, much larger than ii, 

 and carries four or more large hairs, ii bearing only two smaller ones, 

 iii is a single-haired chitinous-based generalised tubercle, iv and v 

 being represented by a double generalised tubercle bearing two hairs. 

 In the second instar, the larva still has a shiny, black head, covered 

 with pale hairs ; the ocelli somewhat prominent, and black in colour ; 

 the apex of the head is divided by a central suture. The skin of the 

 body is blackish-grey, with pale, greyish-white, mediodorsal, subdorsal 

 and supraspiracular lines, and faint subspiracular line. The prothoracic 

 tubercles bear rather long black hairs, those on the mesothorax, meta- 

 thorax and abdominal segments carrying very long red-brown hairs ; 

 the hairs on the dorsum stand upright, those on the supra- and sub- 

 spiracular tubercles curve downwards and completely cover the spiracles. 

 The skin is also covered with small warts, which bear shorter black 

 hairs. The dorsal tubercles themselves consist of two large tubercles 

 on each segment, one on each side of the pale mediodorsal line. These 

 appear to be placed about midway between the front and back edges 

 of the segment, to be composed of a raised wart, and to give rise to 

 four long, radiating, stiff, red-brown hairs. The small hairs on the 

 body surface come from minute scattered skin warts. The interseg- 

 mental membrane is blackish-grey, smooth, without hairs, and is 

 conspicuous when the larva walks. The supraspiracular tubercles are 

 very similar to the dorsal, and the hairs are given off in a very similar 

 radiating manner, but they turn downwards at their ends. There is a 

 pale subspiracular flange, broken at the segmental incisions. The 

 true legs are shiny, black ; the prolegs are blackish-grey Avith pale 

 tips, and black hooks, those on the anal prolegs being particularly 

 well-developed. The 8th and 9th, abdominal segments are rather 

 swollen dorsally, but not distinctly humped as is the larva of 21. 

 neustria of the same age. The anal segment is rough, black, and 

 without hairs. The more adult larva is characterised by the markings 

 being arranged, as it were, in longitudinal lines, running from the 

 prothorax to the anal segment. In the third and fourth imtars, the 

 anterior trapezoidals are well- developed, and bear six or seven hairs 

 stouter than the secondary hairs which rise from the skin surface. 

 These longer hairs are still covered with minute serrations. Bacot 

 describes the adult larva (from blown example) as follows : Head 

 rounded, not large, surface dull, crown black, face and cheeks dull 

 silvery-blue, lines of median and clypeal sutures white ; a thick covering 

 of fine bright brown hairs, a few scattered dark ones (these hairs 

 greatly soften the colour effects and give the blue coloration the 

 appearance of a bloom). Body with dorsal area velvety-black, mottled 

 with narrow longitudinal broken streaks of bright red ; a narrow, much 



