NEMATUS AUKANTJACUS. 173 



the leaf. The larvse feed along its edge, with the 

 hinder part of the body elevated in the air, so as to 

 show the ventral glands, from which exudes a foetid 

 odour when the creatures are disturbed. They are 

 extremely voracious and frequently do very consider- 

 able damage to the various willows upon which they 

 feed, small bushes of Salix caprea being sometimes 

 completely denuded of their leaves by these destructive 

 creatures. There are two generations in the year, 

 one in early summer, the other in the autumn. The 

 brownish cocoon is spun in the earth. 



It was probably the larvae of N. pavidus that are 

 stated to have done great damage to osiers in England, 

 causing a loss of at least 200 annually, mainly by 

 devouring the leaves, and thus destroying the young 

 plants (Mag. Nat. Hist., vii, 423). 



This is a common species in Scotland and probably 

 in England also. The species is parthemogenetic, the 

 eggs laid by the virgin females producing males. 



Its parasites are Mesoleius options, Gr., Tryphon 

 extirpatorius, Gr., and Cteniscus lituratorius, L. 



It is also a native of Sweden, Germany, Holland, 

 France, and Turkey. 



83. NEMATUS ATJRANTIACUS. 



Nematus aurantiacus, Htg., Blattw., 197, 25 ; Andre, Species, i, 



217; Cat., 23,* 176. 



Antennae about the length of head and thorax, covered with close, 

 short pubescence, thin, tapering towards the apex, the third and fourth 

 joints equal, the basal joints entirely black, the middle black, luteous 

 beneath, the apical entirely luteous. Head black, covered with 

 scattered grey pubescence, front projecting, sutures distinct, face, from 

 a little above the insertion of antennae, pale luteous, mandibles 

 piceous, orbits broadly dark, luteous behind the ocelli; clypeus 

 sharply incised. Thorax luteous, mesonotum and sternum black, 

 sutures of mesonotum and two spots on scutellum luteous; cenchri 

 large, clear white. Abdomen bright luteous, the anal segment a little 

 darker above, apex of sheath fuscous. Wings dark hyaline, costa and 

 stigma luteous, nervures fuscous, yellow at the base of wings ; first 



