ENEMIES OF APHIDES. 265 



very rare, a few specimens only having been taken in the north of 

 England and the southern counties of Scotland. It is very similar 

 to Hemerobius, and is said by Dr. Hagen and other writers to be 

 aphidivorous, but there appears to have been but little accurate 

 observation made of its larval habits and development. 



The remaining genus, to the larvae of which the aphis-eating 

 habit is attributed, is Micromus. The young resemble those of 

 Hemerobius, and are said by Mr. MacLachlan to be " probably 

 aphidivorous," but until opportunity occurs for a more perfect 

 examination of their hfe-history, it is scarcely safe to assume so 

 much for a certainty. As yet, I have failed to obtain either egg or 

 a living specimen of the larva. 



In the typical genus of this group of aphis eaters, Hemerobius, 

 the species are, among other features, characterised, as regards the 

 males, by remarkable modifications of the extremity of the abdo- 

 men. These are of great interest for purposes of classification, 

 and in a later number will be figured, when the arrangement of 

 the families and genera is reviewed. Unfortunately, nothing like 

 corresponding diff'erences in structure are visible in the female 

 lace-wings j hence, their value for ordinary working purposes is 

 comparatively little. 



At the lower part of PI. XIII. will be seen at Fig. 6 a peculiar 

 looking insect, the appearance of which would scarcely lead to the 

 supposition that it was a Neuropterous larva. The drawing is 

 taken from Curtis's British Eiitotnology , and represents the larva of 

 the curious little ' lace-wing,' Coniopteryx tineiformis, a fairly typi- 

 cal species of the Coniopterygidce. The fly is frequently to be 

 found in summer on fir trees, in plantations and woods, in com 

 pany with the various aphides that feed on them ; but it is difficult 

 to detect, or at any rate to secure, the larva. Its aphidivorous 

 habits are, however, well established, and for its size there is no 

 reason to doubt that its destructive powers equal those of the 

 larger genera. The larva spin an oval cocoon of densely woven 

 silk, which entirely conceals the pupa formed within it ; and 

 although in the earlier generations of the year the escape of the 

 imago is not long delayed, the pupae of the autumn larvae retain 

 their condition until the following spring, when the continuance of 

 sunshine quickly causes the appearance of the imago. 



International Journal of Microscopy and Natural Science. 



Third Series. Vol. V. t 



