﻿184 L January, 



Notes on Nematus pedunculi, Hartig (" Blaitwespen und Holzwespen," p. 388). 

 — In July of the present year, my friend, Mr. H. W. Kidd, sent to me from 

 Godalming, a large batch of leaves of Salix cinerea, bearing on the under-side 

 numerous slightly pedunculated pubescent galls of about the size of a large pea. 



Their colour was throughout of an uniform green, a shade paler. than the leaf 

 itself, and they preserved this green tinge unaltered until the larvae left them. 

 They were placed principally in rows of two or three along the main ribs. 



The base of deeply seated specimens protrudes sometimes through the upper 

 cuticle, in which case it alone assumes a red tinge. 



Each gall was tenanted by a single saw-fly larva, lodged within a cavity almost 

 equal to the size of the gall. 



When about a line and a-half long, the larvae were whitish-green, their heads 

 dark brown with a black spot each side, within which the eye was situated. 



At 7.30 p.m., on the evening of the 10th July, I noticed a full-fed larva leaving 

 one of the galls. 



It first showed its head through a i*ound hole just gnawed,* and scarcely lai'ge 

 enough to get through. Gradually segment after segment was with difficulty 

 worked out, a strong internal pulsation forward being perceptible all the time. 

 The freeing of the last two or three segments seemed to give it the most trouble, 

 as it rested repeatedly for several minutes after each effort. Why the hole was not 

 previously enlarged enough to admit of an easy and quick exit, I do not understand, 

 except on the supposition, that, when it is sufficiently large to pass the head, the 

 larva's instinct prompts it to force its way out without delay, even with some 

 inconvenience. 



It took the larva in question about fifteen minutes to emerge, and, when clear 

 of the gall, it rested, extended to its full length (3'") for about seven minutes. It 

 was now of a dull olive colour, the head dull pale brown. 



Subsequently it became restless, and began to perambulate without interrup- 

 tion the interior of the jam-pot and the surface of the layer of earth therein con- 

 tained. 



Within a week's time a great number of companions gradually made their 

 appearance, all displaying the same restless disposition, wandering day and night 

 about their prison. But only very few burrowed and spun their thin coffee-brown 

 cocoons of the size of a grain of wheat under-ground. The majority made no 

 attempt to construct cocoons, and gradually died above ground, attacked by some 

 insidious disease. For symptoms of this ailing, I took their becoming lazy, then 

 immobile, stiff, and their assuming a dull reddish hue. When this change occurred, 

 death generally set in within an hour. 



Warned by this failure, which may perhaps be attributed to the close confine- 

 ment and the dampness of the earth supplied, I separated a few still inhabited galls 

 from the rest, and placed them in a large chip box without any earth. When the 

 larvaa of this batch came out, the same impulse of wandering about was shown, 

 but opening the box a few days afterwards, I found they had all disappeared. 



I turned the leaves out of the box, expecting to find the cocoons attached to 



* In this respect, this larva lias a different habit from others of the genus, which long before (heir 

 final exit, keep a hole open for the discharge of " frass," and an occasional pronienndeon the leaf. — A. M. 



