460 



NEUROPTERA 



When the Aveather is wet or cold the Ascalaphi repose on the 

 stems of grass, with their wings placed in a roof-like manner, with 

 the head downwards, and are then very successful in concealing 

 themselves by the positions they assume, and by sidling round 

 the stems to escape from enemies. Some information as to their 

 metamorphosis has been obtained, though knowledge of this point 

 is far from complete even as regards our European species of the 

 typical genus Ascalaphus. For a long time it was supposed that a 

 larva mentioned by Bonnet in his writings was that of Ascalaphus, 

 but Brauer^ is of opinion that such is not 

 the case, and as he has described the meta- 

 morphoses of A. macaronius he is no doubt 

 correct. The eggs (Fig. 303, A), forty or 

 fifty in number, are laid in two parallel rows 

 on the stems of grass. The larvae (Fig. 304, 

 larva of Helicomitus ?) are in general appear- 

 ance somewhat like those of Myrmeleon ; 

 they are .carnivorous in their habits, like 

 the ant-lions, and have similar extraordi- 

 narily developed mandibles. Efforts to rear 

 the young larvae failed, but they were 

 kept alive for some time by supplying them 

 with Aphidides found on Centaureajacea. The 

 cocoon is globular, and the change from the 

 nymph state' to the imago is made in the 



Eggs of 



Fig. 303. a, 



A SGcdaph us viacaro - 

 nius. B, Sketch of 



larvae of Heiico7nitus cocoon, the Structure of the mandibles of the 

 insimuians{i.y, c, out- pvipa being peculiar, and specially adapted to 



line of natural size. -^ ^ ^ -^ . , ^ 9 rw.i i 



The larvae 



(After West wood.) 



in 



the purpose of opening the cocoon.' 

 of Ascalaphides, although so like the ant-lions 

 appearance, do not form pitfalls for the capture of their 

 prey, but lurk under leaves on the ground, or under stones ; 

 they do not move backwards, but progress forwards in an 

 ordinary manner; the habit of backward movement that we 

 noticed in Myrmeleon being probably correlative with the habit 

 of forming pitfalls. Hagen states ^ that the larvae of Ascalaphides 

 and Myrmeleonides, in addition to their peculiarities of form and 

 mandibular structure, are distinguished from those of other 

 Hemerobiidae by the hind legs having the tibia and tarsus united 



1 Verh. zool.-lot. Ges. JVien, iv. 1854, p. 471. '^ Westwood, Ic. p. 12. 



^ P. Boston Soc. XV. 1873, p. 244. 



