Indian forest insects of economic importance Coleoptera . and , • j _,,,.. , ,Remedies borer (vide p. 572). The blue-pine insect, however, only attacks poles and saplings, and will not be found to infest poles whose bark has attained a thickness which results in an outerlayer or covering of old dead bark being present on the tree. For egg-laying purposes the insect requires soft sappy bark. Conse-quently small poles may be felled as trap trees, but they must be fact that they dry fairly quickly does not appear to inconvenience theinsect once the larvae have become half to two-thirds
Indian forest insects of economic importance Coleoptera . and , • j _,,,.. , ,Remedies borer (vide p. 572). The blue-pine insect, however, only attacks poles and saplings, and will not be found to infest poles whose bark has attained a thickness which results in an outerlayer or covering of old dead bark being present on the tree. For egg-laying purposes the insect requires soft sappy bark. Conse-quently small poles may be felled as trap trees, but they must be fact that they dry fairly quickly does not appear to inconvenience theinsect once the larvae have become half to two-thirds grown. In fact, in areas where this beetle exists (and my observations wouldseem to show that it is invariably present wherever the blue pine is presenton a tract, even though the tree may be scarce), an inspection of green felledblue-pine saplings or poles or green branch-wood will almost invariablyeal the fact that they are full of this insect either egg-laying or (depend-ing upon the time of inspection) full of larvae and pupae or maturing FAMILY SCOLYTIDAE 507 From a sylvicultiiral point of view the most serious aspect of this beetleswork is the fact that where the blue pine is scarce on an area, and when afavourable year or succession of favourable years has led to an increase ofthe insect in the forest, the beetle proceeds to attack young deodar owing tothe failure in the supply of the tree it prefers. It is for this reason that the beetle fills a place of considerableimportance in the deodar forest, it being the only genus of bark-borer out-side the Scolytiis at present known to infest the deodar in a serious manner. Chalcid.—The grub is parasitic upon Polygraphus major in blue pineParasitic and and perhaps on PityogenesPredaceous Insects, coniferae (p. 562). Fly.—Highly coloured. Head, thorax, and legs purple, /-with a high metallic sheen ; eyes pink ; antennae nine- toten-jointed, bent. Wings membranous, colourless, witha black elongated bar placed at a
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbeetles, bookyear1914
