268 Destructive Forest Insects of Dumfriesshire. 



yellow legs, and have one or two rows of black dots along the 

 body. It is a very handsome caterpillar. 



Nematus Erichsonii (Large Larch Saw Fly). — It is only of 

 late years that this insect has been much noticed. The presence 

 of it now is notifiable to the Government. The damage is done to 

 the foliage of Larch trees of all species. The leaves are eaten by 

 the caterpillars, which are greyish-green on the back and a lighter 

 green on the sides, about f inch to 1 inch in length. Remedy — 

 Spraying with Paris green or hand-crushing. 



Sirex Gigas (Giant Wood Wasp). — The female of this species 

 is armed with a long ovipositor, and lays her eggs in Scots Pine 

 or Silver Fir. The insects live for two vears in the larval stage, 

 appearing as perfect insects in the third year. They tunnel 

 through the wood, and often emerge after the timber has been put 

 into a building. Tne female is a very handsome insect, resembl- 

 ing a giant wasp. The male is much smaller, and is not so bril- 

 liantly marked. 



Megastigmus Spermatrophiis. — The female insect lays her 

 eggs in the cones of the Douglas Fir, a fact only discovered in 

 recent years by Mr Crozier, forester at Durris, in Aberdeenshire. 

 The mature insect is yellowish in colour, but the shade differs in 

 the sexes. The female is easily distinguishable by her long 

 ovipositor, which is as long as her body. The larvse eat the 

 kernels of the seeds and render them useless. It is thought by 

 some entomologists that a part of the life cycle of this insect is 

 passed as a gall-forming insect on Oaks or other host trees. 



I shall not take up any more time in describing the many other 

 insects that I have found, but I shall give you the names of several 

 saw flies that are gall-forming, and also some other gall-forming 

 flies and a miscellaneous list. 



Gall forming Saw-Flies. 



Pofitania Ischnocerus. Found on Willows. 



Pontania Salicis. Found on Willows. 



Nematus Gallicola. Found on Willows. 



Rhodiies Eglanteria. Found on Dog Rose. 



Rhodites Rosae. Found on Dog Rose (Pincushion Gall). 



Oak Galls. 



Neiiroterns Lenticularis. Spangle Gall. 

 Spathegasier Baccaricm. 



