1903.] Papers. 101 



5. Note on the discovery of Thanasimus sp. prox. nigricollis Lew. in the 



N.-W. Himalayas, with some remarks on its life-history.-— By E. P. 



Stebbing. 



(Abstract.) 



In June 1902, whilst touring in the Tehri Garhwal forests in the 

 N.-W. Himalayas, the writer discovered and took a number of speci- 

 mens of both larvae and adults of a species of Thanasimus prox. nigri- 

 collis Lew. a beetle of the family Gleridse. After remarking upon the 

 close affinities some of the insects found in the N.-W. Himalayas appear to 

 have with those of parts of Japan, the author goes on to show the im- 

 portance of the discovery of the Thanasimus in the valuable coniferous 

 forests in which it was found. It was pointed out that the insect is an 

 eminently predaceous one, and feeds upon both bark and wood-boring 

 Scolytidse, amongst the species fed upon being some serious conifer pests. 

 It thus takes the place in North India of the European T. formicarius 

 which has the same habits in Continental forests, and thus forms one of 

 the most valuable of the insect allies of the forester in those parts. So 

 great is the importance attached to this latter insect in fact that, during 

 some severe bark-boring attacks experienced in America in the pine 

 forests of West Virginia, Virginia and Maryville, between 1890-1892, a 

 well known America entomologist, Dr. Hopkins, was deputed to Europe 

 to make a collection of living larvae and adults of the predaceous clerid 

 for importation into America. This experiment was conducted to a satis- 

 factory issue. 



Our Indian Thanasimus has pink elongated larvae which feed upon 

 the larvae of the Scolyted beetle upon which it itself as an adult lives, 

 and it is thus of great service during both the grub and adult stages of its 

 existence. The pink grubs seek out the bark-boring grubs in the 

 galleries in the bark of the tree. The clerid beetles, on the other band, 

 spend the whole of their life outside the tree, and seize the bark beetles 

 upon the bark of the trees either whilst engaged in boring into or issuing 

 from the tree. 



The Thanasimus adult is probably to be found during most of the 

 months between April and October. The writer by experiment has 

 proved it to feed upon 10 different species of Scolytid beetles. 



As the Indian Thanasimus is much larger than its European confrere, 

 being almost double the size, it is probably of even greater value iu the 

 forest, since it consumes a greater number of beetles during its existence. 

 The beetles is polygamous. 



As an instance of the immense amount of good such an insect can do 

 in the forest the following illustration of the immense powers of rapid 

 reproduction possessed by Scolytidae is quoted, 



