52 THE ENTOMOLOGIST. 



In this wood, as well as in the second, the trees bear crowds 

 of Lachnus pinicola, which, however, are kept under control by 

 Ladybirds, chief of which are Coccinella ocellata, Mysia oblongo- 

 guttata, Adalia obliterata, and a strong sturdy form of the Seven- 

 spot Ladybird {Coccinella septempunctata) . This form is larger, 

 and is of a deeper red than the type, and, as I have only seen it 

 in pine woods, I call it var. pini. The larvae of these beetles can 

 be observed in great quantities in some seasons. In spite of the 

 good work done by all these friends, the larches in both woods 

 are being killed off slowly but surely ; in the first, Coleophora 

 laricella is the culprit, and in the second, the Woolly Larch 

 Louse {Cherines laricis). These are not only destructive in 

 themselves, but both so weaken the trees that they cannot 

 resist the attacks of the Larch Fungus {Pezlza ivillkommii) , the 

 spores of which find an entrance at the injured points. In the 

 end, Sirex noctilio singles out the affected trees, and the presence 

 of the huge grub of this insect soon causes their final collapse. 

 I do not think that either Sirex gigas or S. noctilio ever attacks 

 sound trees, for I have twice seen S. noctilio ovipositing, and in 

 each case the tree was in a dying condition. Lastly, all the 

 trees containing Sirex larvae had, when I examined them, been 

 in a poor state for a long time, and consequently bore no low 

 branches. 



It seems to me an extraordinary thing that such destructive 

 insects as Coleophora laricella, Chermes laricis, and C. abietis are 

 ever allowed to get into our coniferous woods, for they are not 

 native insects. If all nursery stocks of both spruce and larch 

 were sprayed in April and May, either with petroleum and flour 

 emulsion, or lime sulphur wash * or with any arsenic spray, it 

 would be impossible for these pests to reach new plantations. 

 If preferred, the spraying could be done for two consecutive 

 Springs on the young transplanted larches when the hybernated 

 Coleophom larvae are renewing their cases, and the supply of 

 needles, both for that purpose and for food, is limited. At the 

 same time Chermes laricis and its form C. abietis are in their 

 most defenceless condition. After the trees are once established 

 the cost of spraying would be prohibitive. 



I could not help contrasting the poor state of these larches 

 with the stately larches and spruces in the other two woods. It 

 was not that the various enemies enumerated above were absent, 

 for I could see signs of practically all. It was because they were 

 all under the control of their natural enemies. What, then, are 

 the natural enemies of Coleopliora laricella, Chermes laricis, and 

 its form on the spruce, the Spruce Gall Louse {Oiermes abietis) ? 

 By beating larch, spruce, and juniper, a simple answer was 



''' This wash if not carefully used would injure the young foliage. 

 Recent experiments, however, on peach trees, have shown that even their 

 delicate blossoms escape unharmed when the spray is in competent hands. 



