the Biology of some British Neuroptera. 585 



Phylloxera in captivity and grows well at first, but in no 

 case have I a complete record of the life-history. For some 

 reason, feeding ceases before arriving at maturity and death 

 ensues. This may be due to a fungoid disease which 

 has been observed to attack larvae of Comventzia. Larvae 

 have been beaten from oak, beech and pine. 



Description of Third-instar Larva. (Plate XLIII, fig. 3.) 



Length when full fed 2-5 mm. Colour yellow, orange, or almost 

 pale crimson. More elongate as a rule than pijgmaea and approach- 

 ing the form of a Conwentzia larva. 



Head whitish; eyes dark crimson; antennae translucent and 

 colourless, the distal portion three or four times the length of the 

 basal joint. Palpi colourless. 



Body somewhat fusiform, but broader anteriorly and tapering 

 gradually to the anal extremity. Colour uniformly yellow, orange, 

 or orange-crimson, — no markings. Legs pale yellowish, translucent. 



The above description answers well for examples of 

 C. tineiformis found on deciduous trees such as oak and 

 beech. In the summer of this year, however, some larvae 

 were taken on conifers, under the impression that they 

 were fairly large specimens of C. pygmaea. These have 

 since turned out to be G. tineiformis, and consequently 

 the larvae of these two species of Coniopteryx (on pine) are 

 not so distinct as I once thought. This is probably due to 

 the difference in nature of the food, but it emphasises the 

 desirability of finding structural characters on which to 

 separate the larvae. 



A small, flat, circular cocoon of white silk is spun for 

 pupation, on the bark of trees, etc. The outer envelope 

 is of about 3 mm. diameter and is attached to the inner 

 envelope. Double structure is not marked. In about 

 two weeks after spinning (65° F.) the imago appears. 

 Winter is passed as a larva within the cocoon. 



The food of this species, when on oak and other deciduous 

 trees, probably does not differ from that of Comventzia 

 psociformis. 



Semidalis aleurodiformis Stephens. 



Wing expanse about 8 mm. The wings of Semidalis are subequal, 

 the media in hind-wings is forked, which chai-acter separates from 



