162 SUB-GROUP OF SALICIS. 



entirely Hack or black only above. Wings hyaline, or 

 they may be tinged with yellow. 



This section contains some of the commonest species 

 of yellow Nemati. From the group of Betulce the 

 species may be known by the incised clypeus ; from 

 Myosotidis by the abdomen being only black at the 

 base, and by the bright yellow colour ; from the group 

 of Luteus by the short ovipositor 5 and from Croceus 

 by the greater expansion of black on the thorax, by the 

 brighter yellow colour, and by the black antennae. 



The group contains three sub-groups, which, however, 

 merge closely one into the other, so that it is difficult 

 to clearly differentiate them, while two or three of 

 the species might be as well placed in the Croceus 

 section, and the smaller forms run into the gall-making 

 group. 



SUB-GROUP or SALICIS. 



Yellow, head and mesonotum more or less black ; antennse long- 

 ish, black, rarely brownish beneath. Stigma black, costa 

 pale, or fuscous. Clypeus incised, but not deeply nor 

 sharply. 



These are the largest and commonest of the yellow Nemati, and 

 are not difficult to recognise by the yellow abdomen and 

 blackish stigma. 



Synopsis of Species. 



1 (6) Antennse and scutellum black. 



2 (3) Head luteous, vertex black, breast luteous. Salicis. 



3 (2) Head black, breast black. 



4 (5) Mesonotum entirely black, head marked with yellow, hinder 



tarsi yellow. Melanocephalus. 



5 (4) Mesonotum with three marks, scutellum and metanotum black 



more or less, head not marked with yellow, hinder tarsi 

 black. Collinus. 



6 (1) Antenna^ scutellum, and metanotum for the greater part yellow. 



Eibesii. 



