Large Larch Sawfly Nematus Erichsoni PDF Download

Excerpt from The Large Larch Saw-Fly (Nematus Erichsoni) The females begin to deposit their eggs almost immediately after emerging from the cocoons, especially if the weather is warm and sunny as they reproduce parthenogenetically there is no necessity for them to await fertilisation by the male. The eggs are deposited on the stems of the fresh green terminal shoots in small slits made by the saw-like appendages of the ovipositor. The slits are made along the shimts'with the result that the green terminal shoot is killed by the numerous wounds and curls round in a characteristic m'anner (fig. The presence of these brown and curled dead terminal shoots is often a means of detecting the presence of the larvae when they do not occur in sutiicient numbers to indicate their presence by much defoliation of the twigs. The eggs appear to be deposited chiefly on the lower branches of. The trees, as I found. That on the trees which were only moderately attacked the larva: were most numerous on the shoots of the lower branches and these usually showed signs of defoliation bei't re the branches nearer the top of the tree. The beginning of the attack on the lower branches is probably explained by the. Fact which has already been mentioned, namely, that the females begin. To lay almost im mediately after emergence they would naturally on emerging from the cocoons lying beneath the turf, &e., fly on to the lower branches first. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.