. Forestry. ig. i8r),with their flaccid yellow tips, givethe trees a very striking appearance,as though they had suffered fromfrost. Prevention consists in plantingLarch only upon suitable situations,where it has good and naturallywell-drained soil, with free circula-tion of air about the crowns. Closewoods of Larch are therefore notto be recommended. The LarchMining Moth is very generally asso-ciated with the fungus which causesLarch disease. Hymenoptera Pine sawfly, Lophyrusptni. Thefemale, with her saw-like ovipositor,bores into the needles of the ScotsPine and deposits a large number ofegg
. Forestry. ig. i8r),with their flaccid yellow tips, givethe trees a very striking appearance,as though they had suffered fromfrost. Prevention consists in plantingLarch only upon suitable situations,where it has good and naturallywell-drained soil, with free circula-tion of air about the crowns. Closewoods of Larch are therefore notto be recommended. The LarchMining Moth is very generally asso-ciated with the fungus which causesLarch disease. Hymenoptera Pine sawfly, Lophyrusptni. Thefemale, with her saw-like ovipositor,bores into the needles of the ScotsPine and deposits a large number ofeggs. The caterpillars, which aregreen and grow to one inch inlength, have twenty-two legs. Theyfeed in clusters, gnawing and totallydestroying the needles. There maybe two generations in the , hatched early in the season,pupate in June on the needles andbark ; those of a later brood turnto chrysalides under the soil cover-ing of leaf litter. In young plantations the colonies of larvae may be crushed. FIG. 18TWIG OF LARCH SHOWINGNEEDLES ATTACKED BVLARCH MINING MOTH a. Larval cases. b. Larvoe suspended by threads. c. Hollowed needles. 86 FORESTRY with the hand, but it is impossible to cope with the pest inolder woods. Hemiptera Spruce-gall aphis, Cheilites abietu. After wintering underscales in the bark, the so-called mother aphis appears inspring. She pierces into the twigsof the Spruce, and through irritationthus caused a cone-like gall (Fig. 19)arises. Here eggs are laid amongst awoolly secretion, and the tiny aphidescoming from these suck the juices ofthe gall, which, from being quite in-significant, increases to the size of asmall pine cone. The aphides becomeenclosed in the gall, where they oc-cupy cells or chambers until full-grown in August. At that time thegalls turn to a brown colour, and thechambers split open, allowing thegreen-fly to escape. If Larch be athand, some of them fly to it and de-posit eggs; from these a female form ishatched, which seeks protecti
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