1920.1 161 



segmented, and to have numerous veiT minute colourless hairs. These 

 are very numerous on the extemity of the last segment both above and 

 below the anus; the longest here are about 0'025 mm. long; those on the 

 body are rather shorter, averaging about 0'02 mm. Three subsegments 

 carry most of these; they are in not quite straight rows across the body; 

 the subsegment in front of the spiracle has most, about 20 across from 

 spiracle to spiracle ; the subsegment above the spiracle has much fewer, 

 and the next subsegment an intermediate number. The pro-legs also have 

 a good many of these hairs. 



April 30th. — The larvae grew considerably in 1st instar, to 5 mm., 

 and in several cases the heads were not as black as in those noted above. 

 To-day there are several in 2nd instar; the heads are much paler when 

 newly moulted. Those larvae that are somewhat grown reach 8 mm. in 

 length in this instar. The larvae are still nearly colourless wherever 

 a gap in intestinal contents prevents their green colour dominating the 

 nearly colomdess background. The subsegmentation is more easily seen 

 than in 1st instar. The hairs seem scarcely as numerous as in 1st instar, 

 and are comparatively much shorter — viz., 0'03 mm. (0"0012 inch). 

 Of these, there is a row across each abdominal segment : on a subsegment 

 rather behind the middle of the segment they are rather farther from 

 each other than their own length. There are fewer on other subsegments, 

 but in two cases amount to sparse rows. There are a good number on 

 pro-legs, and last segment is well clothed ; the spiracular region has 

 generally a few extra scattered hairs. 



On May 2nd several larvae reached the third instar, and were about 

 10 mm. long. Except size, there is nothing to distinguish them from 

 2nd-stage larvae Like them they seem hairless till well magnified, when 

 hairs about 0'03 mm. (00012 inch) long are visible. Of these, there is a 

 row across each abdominal segment, rather behind its middle, rather 

 further from each other than their own length. An imperfect row near 

 the front of the segment ; a good many about the spu-acles, the pro-legs, 

 and especially the posterior extremity of the larva, differing scarcely at 

 all from their dispositions in other instars. The larva is still nearly 

 colourless apart from intestinal contents. 



In the 4th instar the larva is larger, but the description of 3rd 

 instar would otherwise apply. The head is pale for a short time after 

 moulting, but soon becomes black, except about the mouth-parts, 

 which are paler. 



On May 9th several appear to be in last instar, 17 mm. long. 



P 



