FAMILY SCOLYTIDAE 507 



From a sylvicultural point of view the most serious aspect of this beetle's 

 work is the fact that where the bhie pine is scarce on an area, and when a 

 favourable year or succession of favourable years has led to an increase of 

 the insect in the forest, the beetle proceeds to attack younj^ deodar owing to 

 the failure in the supply of the tree it prefers. 



It is for this reason that the beetle fills a place of considerable 

 importance in the deodar forest, it beinf( the only ji^enus of bark-borer out- 

 side the Scolytus at present known to infest the deodar in a serious manner. 



Chalcid. — The grub is parasitic upon Polygraphns major in blue pine 

 Parasitic and and perhaps on Pityogenes 



Predaceous Insects, coniferae (p. 562). 



Fly. — Highly coloured. Head, thorax, and legs purple, 

 with a high metallic sheen ; eyes pink ; antennae nine- to 

 ten-jointed, bent. Wings membranous, colourless, with 

 a black elongated bar placed at about the middle of the 

 upper one. Tibiae black, with a yellow pubescence ; tarsi 

 yellow, last joint black. Body blackish purple, but without 

 the high iridescence of thorax and head ; apex blunt. 

 Length, 5.8 mm. ; wing expanse, 12 mm. 



The fly has been identified as a species of 

 Chalcid. Fig. 330. — Chalcid parasitic on 



, r Polvgraphus ?najor. North- 



Lifc History.— Towards the end of June West Himalaya. 

 1902 I took some specimens of this fly from 



their pupal chambers at the end of the larval galleries of Polygraphns 

 major in blue-pine branches. The branches were badly infested with 

 both the Polygraphns and also Pityogenns coniferae, and the insect may 

 also be parasitic on the Pityogenes. I was not able to ascertain definitely 

 this point. The fly evidently lays its eggs at the mouth of the entrance- 

 hole made by the bark beetle in the branch, or crawls down it and deposits 

 them in the egg-gallery. The chalcid grub probably feeds on the scolytid 

 one as an external parasite The insect is a most useful one. 



Niponius canalicollis, Lewis (p. 103).— This predaceous histerid feeds on 

 the eggs and larvae of the Polygraphns and other coniferous Scotytidae. It is 

 found throughout the coniferous forests of the Western Himalaya, and 

 also in the Pinus gerardiana forests of North Zhob in Baluchistan and 

 in the Suliman Mountain Range. 



i^i^tV/t'.— Elongate, narrow, cylindrical. Shining black in colour, tarsi palish ; the elytra 

 are short, and leave exposed two segments of the body. Prothorax with a conspicuous median 

 channel, sometimes reaching the base, but always shortened in front ; surface on either 

 side of channel uneven, the punctures irregular in size and form. Elytra with the sutural and 

 one humeral striae complete, the others punctiform or obsolete. The fovea on the pygidium 

 large and circular. The tibiae slender. Length, 3^ mm. to 4^ mm. 



Larva. — Elongate and flat, pink in colour, with a yellow head and twehc pink or red 

 body-segments. Length, 12.5 mm. 



The larva is to be commonly found in the larval galleries of the scolvtid beetles. 



