the Biology of some British Neuroptera. 559 



The head and its appendages are, as a rule, unmarked, 

 but in some examples, especially those of a fuller green 

 colour, the palpi may be banded with blackish. Thus 

 such examples aj)proach very nearly to C. flavifrons, and 

 this resemblance is sometimes increased by the head being 

 entirely yellow in colour. The head itself, however, and 

 the pronotum are always immaculate. The characters 

 which I have found most useful in separating alba from 

 similar species, are firstly the strongly ciliated costa, and 

 secondly the long subgenital plate of the male. In other 

 British Chrysopids the costal cilia are not so long and do 

 not stand out so straightly from the margin, but rather 

 tend to lie down along the costa. I am, nevertheless, 

 strongly of the opinion that we have here tv/o forms which 

 are at least to be regarded as subspecies, and which are 

 quite as distinct as C. j^^^^sina and vcniralis are from one 

 another. This difference is also observable in the larva. 

 Typical alba larvae have very long thoracic warts, as figured, 

 while in the form of which the imago has black marked palpi 

 the larval warts are much shorter and more like those of 

 C. flavifrons. C. alba is one of the most difficult species 

 to breed that I have as yet encountered, usually dying in 

 the second or early third instar, or in winter when within 

 the cocoon. 



The favourite haunts of this species are shady deciduous 

 woods, where it is often extremely abundant in June and 

 July. There appears to be no second brood. 



Eggs are laid singly or in very well-spaced clusters 

 of three or four on the undersides of leaves. This applies 

 to both forms. The egg is -8 mm. long, pale green in colour 

 and borne by a stalk about 5 mm. in length. As hatching 

 approaches the colour becomes whiter, and the eyes of 

 the embryo, also brown transverse lines indicating the 

 segments of the abdomen, appear. 



The young larva is about 1-3 mm. long, white in colour, 

 later with a tinge of brown or grey. The head markings 

 appear after some hours, but are variable and not generally 

 as in the older larva. Sometimes there is a black patch on 

 the posterior part of the head, from which two diverging 

 lines extend forward in the direction of the bases of the 

 jaws. In other examples only the two diverging lines are 

 present. Skins are placed on the back with the jaws, 

 later the load increases, and the cast skin at each moult is 

 added to the coat. The larvae are sluggish, and at first 



