INDIAN FOREST INSECTS 



It is not possible, however, to 



obtain a previous warning in all 



cases. For instance, the Mono- 



phlebiis sal scale, which infests the 



^ sal in the Siwaliks and United 



Provinces sal forests, generally 



affords, so far as is at present 



known, no such previous evidence 



of a bad attack — such attacks, e.g., 



as were experienced between i8g8 



, I and 1902 in this region. 



• The forester is on safer ground 



when he wishes to ascertain the 



;.j; abundance in the forest of the 



''" bark- and wood-boring pests of his 



trees. It is always possible for him 

 to keep himself posted with practi- 

 cal certainty on this point. If you 

 walk through a wood in Germany 

 or France you will find felled green 

 trees at intervals lying to one side 

 of the road or path. These trees 

 have been felled with the express 

 purposeof enabling the forest officer 

 to keep himself informed as to the 

 presence of and abundance of the 

 ? ' bark-boring and timber-boring in- 



sect pests which infest the parti- 

 cular species of tree of which his 

 forest is composed. By cutting off 

 |; ; a square of bark at the period at 



K^ which he knows the insects will 



*f be on the wing in the forest, he 



will be able at once to ascertain 

 their abundance. For both bark- 

 borers and wood -borers will resort 

 to these freshly felled trees to o\'i- 

 posit instead of searching for sickly 

 ■ trees or fresh windfalls in the forest 



itself. He will, therefore, find these 

 ;' insects at work boring through the 



« bark to oviposit in the bast, or tun- 



nelling down into the timber to 



, . r ■ r . -i • hiy their eggs there. If at any 



Fig. 24.— Iiilenor of section of a stem, showing -^ . /^'= ■' 



pupating-chambers of a longicorn beetle. period he finds these trees lull ot 



