STRYMON PRUNI. 203 



of the position of rest of the larva, and position selected for pupation, 

 will give any reasonable collector as many larvae or pupae as he may 

 require in a normal season. Rothschild says that, at Ashton Wold, 

 the larvae feed on the higher sloe bushes, and are generally fullfed 

 about the third week of May. The larvae are best obtained in 

 Whittlebury Forest by beating sloe bushes, but even here it is very 

 local, and never abundant (Foddy). We can find very few actual 

 records of the dates on which larvae have been taken, but note: Larvae, 

 June 1st, 1877, in Monk's Wood (A. H. Jones); larvae, June 5th, 1877, 

 in Monk's Wood; fullfed larvae, May 3rd, 1893, near Oundle (Bower); 

 larvae abundant, May 19th, 1897, at Ashton Wold (Sheldon) ; larvae, 

 May 23rd, 1897, near Peterborough ; pupae, found May 30th, 1897, 

 near Peterborough (Pearson) ; larvae, nearly fullfed, May 15th, 1901, 

 in Monk's Wood (Ash); larvae, May 20th, 1906, in Monk's Wood (Kaye); 

 larvae fullfed June, 2nd 1907, at Ashton Wold (Rothschild). 



Larva. — First instar (newly -hatched) : Short, thick, under 2mm. 

 long unless stretched. It has the usual Theclid rows of hairs down 

 the back, i.e., i and ii on each side. The hairs are all finely spiculated, 

 that arising from tubercle i is much the same from the 2nd thoracic 

 to the 8th abdominal segments, rather shorter on first and last of these; 

 it is, at longest, about 0'4mm. long, stands fairly erect, but with a 

 sweeping curve that makes the tip directed somewhat backward ; the 

 seta of ii is a little further out, but close to that of i (both being a good 

 space from the corresponding hairs of the opposite side) ; it is two- 

 thirds the length of i in front, but shorter behind, about half the length 

 of i ; it lies more flatly to the larval surface, so that the tip points 

 directly backwards, it is curved similarly to i. The next marked feature 

 is a row of lenticles, a little nearer to i and ii than to the spiracles, they 

 occur on the metathorax and the 1st to 7th abdominal segments. 

 There are, on each segment, a pair at this situation, a large one and a 

 smaller below and behind it ; on the metathorax the lower is the larger, 

 but on the 7th abdominal segment both are small, and the lower is 

 lower down, near the spiracle. The spiracles are large and obvious, 

 nearly as large as the lenticles. Below the spiracles (abdominal), is a 

 group of four hairs on each segment ; these are probably iv and v, 

 and occupy the flange; there is no iii, unless the lenticles represent it. 

 These four hairs are placed two above at a level, and two below; of these 

 the posterior is the lower. Then there are two small hairs, a little above 

 foot level, on all the thoracic and the first 7 abdominal segments. On the 

 3rd abdominal are three (probably an aberration), and one only on the 8th 

 and 9th abdominals; each of the 8th and 9th abdominals carries, however, 

 a large lenticle above these and below the four of the marginal group 

 of hairs. The prothorax has a rather large dark plate with two small 

 lenticles on each side, and apparently three hairs ; it is diamond-shaped, 

 the outer (long) and front angles being acuminate; the posterior edge 

 full, but rounded ; there are three short hairs along the outer portion 

 of its front margin, about 0'12mm. long; and two fine ones in front of 

 the spiracle. On the metathorax there is a hair on each side of the 

 front margin ; nearer the middle line than i, behind these, is a little 

 irregularity, as if an obsolete plate ; just in front of i and ii is a 

 lenticle; it possibly belongs to the "slope" series of the following 

 segments, but if so it is much out of alignment with them. The 

 meso- and metathorax each have two hairs, apparently ranging with 



