Qilian Mountain Nature Reserve In Qinghai Spruce Pests Integrated Control Technology,

This article summarizes the improvement of research in conifer seed insects of home and abroad, and its primary purposes: (1) investigating the kinds and harmfulness of picea crassifolia seed insects;(2) analyzing the distributing characters of the main seed insects;(3) analyzing the reasons of forming different stricter characters of seed insects;(4) analyzing the food competition amony these main seed insects, in order to give reference which we need when we should take some measures to prevent and control seed insects.Through investigating picea crassifolia seed insects in these distributing center——the northslope of Qilian Mountain, I found fourteen kinds of seed insects, in which there is one new kind and one new registering kind. According the kinds and main distributing of picea crass folia seed insects, I separate four small sections (Ⅰ, Ⅱ, Ⅲ, Ⅳ) . The severity order of kinds, occurring area and harmfulness follows the laws: (1) the east forest zone of Qilian Mountain, close forest, mixed forest respectively, (2) with the altitude and the slope degree increasing, the severity is dropping gradually, on the contrary, with precipitation of the forest zone decreasing, the severity is moving up. (3) Young seed stands and mixed forest in high latitude are infected insignificantly, but the forest in gentle places is infected seriously. (4) there is no significant difference in different slope orientation, and seed orchard which is far to nature forest isn't infected generally. Besides, the severity order of population quanity follows the law: Ⅰ> Ⅱ>Ⅲ>Ⅳ, and the severity order of harmfulness follows the law: Ⅱ>Ⅲ>Ⅰ>Ⅳ. The population quanity of pseudotomoides, strobilellus tdia strobilella, Tormus caudatus,...