ON THE LIFE HISTORIES OF FOREST INSECTS 



33 



2, Life History of tlie buprcstid Sphcno[>tcra atcvriiiia and the ccrambycid 



Trinophylluiii cribyatiini. 



Green deodar-trees were felled under the orders of the Divisional 

 Officer, Mr. V. Monro, at the end of May igo8, and watched throu<;hout 

 the year and up to June of the following year. The observations so made 

 and the specimens taken enabled the life histories of these two pests to 

 be definitely ascertained. It is now known that each takes a whole year 

 to pass through 

 one life - cycle 

 (cf. p. 205 a n d 

 p. 341), and that 

 the beetles ma- 

 ture and leave 

 the trees at the 

 end of May or 

 in I he first fort- 

 night of June, 

 and lay their 

 eggs in n e w 1 }■ 

 felled fresh 

 sappy trees or in 

 standing green 

 sickly ones. 



The life his- 

 tory of an Ich- 

 neumon fly, 

 Ephialtes, which 

 parasitizes the 

 buprestid grub 

 has also been 

 worked out 

 through the 

 year (see p. 207). 



The impor- 

 tance of thus in- 

 vestigating the 

 life histories of 

 all the principal 

 bark- and wood- 

 feeding pests of' 

 the more impor- 

 tant trees cannot 

 be too strongh' 

 insisted upon. 

 9003 



Fig. 19. — Egg and larval galleries oi SpJiaerotrypes skualikensis, 

 Steb., on inner surface of sal bark, showing the " plan " of the 

 galleries. 



