26 



INDIAN FOREST INSECTS 







Fir,, i f). Central vertii L] egg -alleries from which 

 radiate ilic larva] -alk-rk-s made in the outer 

 .sa|m,..,d of a sal-tree by the bark beetle 

 Sphaerotrypes. 



(3) The insect fauna of the 

 Indian forests has never till 

 within the last few years been 

 systematically collected. 



The life histories of many 



J 



of the forest-living insects are 

 of uncommon interest, and in 

 nothing perhaps are they so re- 

 markable as for the instinct 

 which many of them seem to 

 possess many beetles, for ex- 

 ample, such as the Buprestidae, 

 Cerambycidae, and Scolytidae, 

 to instance three important 

 families only --which enables 

 them to seek out newly felled 

 or sickly dying trees in as un- 

 erring a manner as that of the 

 soaring vulture in his detection 

 of the newly dead carcase. No- 

 thing can be more striking than 

 this wonderful power. Inspect 

 a felling area a few days or a 

 week or two after the trees have 

 been cut. If you examine the 

 bark of a felled tree you will 

 perceive on its outer surface 

 numerous shot-holes, or num- 

 bers of little cones of sawdust, 

 or small patches of sawdust. 

 Take off a strip of the bark and 

 examine it on the inside. You 

 will rind on it, and perhaps on 

 the outer surface of the sap- 

 wood, small galleries or plans of 

 several galleries, and in them 

 perhaps one or two small blackish 

 beetles, and at the head of the 

 still incomplete off-set galleries 

 small whitish dots, one at the 

 head of each little gallery (cf. 

 frontispiece). The little beetles 

 are bark beetles (Scolytidae), and 

 the little grubs have already 

 hatched out from the eggs laid 



