222 BRITISH LEPIDOPTERA. 



near Glogau, once provided 33 larva?, which were crawling up the 

 stem. The young larva? are to be found on the lichens in summer, 

 autumn and early spring, being fullfed in May, when they climb up 

 fences, tree-trunks, &c, for pupation. In some years {e.g., 1850) they 

 are very abundant. The pupal stage lasts about three weeks (Zeller). 

 It appears to us certain that the larva? are almost (? always) entirely 

 ground feeders, coming up on trees, fences and walls, only at the time 

 of pupation. Alderson notes tbat from March until June 3rd, 1899, 

 he regularly searched the fences near Farnborough without success, 

 when, on the latter date, he found no less than a dozen on a fence 

 at about a foot from the ground, although a couple were up 4ft. or 

 more. They also appear to be most abundant where there is a strip 

 of herbage at the bottom of the fence, and very scarce where the 

 ground is clear. He considers that they must come to the fences only 

 for pupation. 



Larva. — Emerged July 5th, 1899. As soon as hatched, l'25mm.- 

 l'5mm. in length when crawling (when at rest about l-125mm.), 

 about -25mm. in width. Head and thorax large, a slight constriction 

 between thorax and abdomen ; body round and nearly cylindrical when 

 contracted, but flattened and showing a strongly developed lateral 

 flange when stretched, in crawling. Head large, carried rather hori- 

 zontally, pale, but bright, brown, glossy ; prothorax large, well covered 

 by a corneous plate, coloured as head ; mesothorax shorter, also 

 covered dorsally by corneous plate ; metathorax with central dorsal 

 plate of triangular shape, and two subdorsal plates, all pale brown ; 

 anal plate large and showing up clearly. The plates at the bases of 

 hairs on the abdominal segments are large and well developed, looking 

 comparatively larger and more prominent than in adult - larva (this 

 probably will be less noticeable when the larva has fed and the skin 

 has been stretched) ; the hairs longest on head, the thoracic and anal 

 segments. The true legs strong ; segmental incisions sharply defined, 

 though not deep. The abdomen broadens laterally at 4th and 5th 

 segments and then tapers again. The prolegs are very short. On 

 front edge of prothorax is a loose fold of soft white skin, showing the 

 head to be fairly retractile. The tubercular plates are very large and 

 pronounced ; those at base of i so nearly join in median line that they 

 appear at first sight to form one central triangle, as on metathoracic 

 segment ; the suture is especially difficult to detect on the 1st 

 abdominal ; the arrangement is as in the adult larva, i inner, ii slightly 

 outer, iii with the hair not quite so prominent as is usually the case in 

 Psychid larvae, iv and v (subspiracular) appear to be in about the same 

 horizontal plane, hair on anterior (v) is very small ; the exact bases of 

 hairs (especially dorsal) are difficult to locate, possibly i and ii are on 

 the outer and inner edges of plates, as in adult larva. The fall-fed 

 larva is somewhat long compared with its bulk, about 9mm. -10mm. in 

 length, and l*5mm. in greatest thickness. The head, legs, and thorax 

 rather weak compared with the abdomen ; the head and thorax form 

 about one-quarter of the length of the larva. The abdomen is of 

 more even bulk, and less grub-like than those of any other Psychid larva? 

 examined. It curves its abdomen ventrally almost as much as some 

 sawfly larva?. In the proportions of length and comparative slender- 

 ness it resembles P. villosella and 0. unicolor rather than the Soleno- 

 biids and Luffiids. If touched on the head it executes a rapid back- 



