20 



INDIAN FOREST INSECTS 



Small bast-living forms of the Staphylinidae also prey upon various 

 scolytid bark-borers or their grubs. 



Many of the Coccinellidae are active predators 

 both in the grub and beetle stage. For instance, 

 the coccinellid Vedalia (p. 125) preys upon the sal 

 coccid scale insect Monophlehns stcbbiugii, whilst 

 the cosmopolitan Coccinella septempnnctata (p. 123) 

 preys upon the Aphis of the blue pine, the 

 Lachnus of the silver fir, and upon the young grubs 

 of the Chermes himalayensis. 



The beetle Cissites (p. 248) oviposits in the 

 tunnels of the carpenter bee, Xylocopa latipes, in 

 pyinkadu, its grubs feeding upon those of the 

 latter. 



Finally, to come to the Rhynchota, the bug 



Erthesina fullo feeds upon the caterpillars of the 



sal-defoliator Boarmia selettaria in the United 



Fig. ii.—Hectarthrum uni- Provinces Terai forests. 

 fortne^ Waterh., which 



5"S.-;r^iS? In (^) Parasites, or Insects which live parasiti- 



Tenasserim. CALLY UPON INJURIOUS SPECIES, SLOWLY 



KILLING THEM. 



The number of insect parasites, as also of that far less-known branch, 

 the fungus parasites, of the insect world is very great. The forester, and more 

 especially the forester in India, where the individual charges are of such 

 vast size and the forests of such enormous extent, is very largly dependent 

 upon the parasites which decimate and keep in check the insect foes of 

 his trees. It is therefore of considerable importance that he should be 

 able to recognize the presence and abundance of such valuable coadjutors 

 in his work of protection. That this is by no means a difficult feat will soon 

 become evident to the forest-trained eye. One has only to repair to a felling 

 area, and carefully scrutinize felled trees which have been lying in the 

 forest from two to three weeks with the bark on. The presence of various 

 bark-borers will soon be noted, intent on tunnelling into the tree to eat 

 out their egg-galleries in which to oviposit, or crawling over the bark 

 searching for a favourable spot to start their tunnelling operations. In 

 the Western Himalaya the predator Thanasinius may be noted flying round 

 or running quickly up the bark, searching eagerly for the bark-beetles. 

 Watch closely and you will see numbers of minute flies hovering about, or 

 settling upon the bark and disappearing down the entrances to the tunnels 

 made by bark-beetles who have already got well down through the bark 

 and reached the bast. These flies are parasitic insects, the friends of the 

 forester. They creep down the tunnels of the bark-borers and lay their 

 eggs in the galleries in the bast. The young grubs, on hatching from 

 these eggs, feed parasitically upon the grubs of the bark-borer, clinging 



