184 



FOREST ENTOMOLOGY 



PONTANIA ISCHNOCERUS (ThoUl.) 



Nemaius ischnoceni,% Th. 



I have only found this species at Kielder, Northumberland. 

 Cameron gives three localities — viz., Eannoch, Braemar, and New 



Galloway. Fig. 172 is a rep- 

 resentation of the galls on the 

 leaves of a species of Salix. 

 This species cannot in any way 

 be considered as an important 

 forest insect, except in so far as 

 it is of interest in a collection. 



Genus Ptbronus. 



.—G'liJls o/Pontania ischnocerus on 

 species 0/ Salix. 



selected 

 history 



This genus contains a number 

 of species which have been 

 from the old genus Nematus, as regards structure and life- 

 peculiarities. Perhaps the best plan for the student to 

 master the same from a typical species is 

 to work out the life-history of the goose- 

 berry saw - fly, P. rihem, Scop., hitherto 

 known as Nemafus rihesii. For specific 

 characters the systematic student is advised 

 to refer to the " Synoptic Table of British 

 Pteromiff," by Eev. F. D. Morice, in the 

 ' Entomologist's Monthly IMagazine ' for 

 June 1906. 



Pteronus salicis (Linn.) 



It often happens that in our early 

 summer or late autumn rambles we find 

 bushes of Salix caprea' defoliated by saw- 

 fly larvae, as in fig. 173. In this case the 

 insects proved to be P. salicis, as identified 

 by Eev. F, D. Morice. 

 The perfect insect has black antenna?, black or dark-brown stigma, 

 and in both sexes a bright orange-coloured abdomen. 



The insect is double-brooded, and can be very easily hatched out. 



Fig. 173.— Icff/ of gout irilhm- 

 (Salix caprefe) eatof hy larva: 

 o/Poiitania salicis. 



