| This thesis research main insect pest in Dailing district in Yichun city, with ownership larch caterpillars occurrence regularity and prevention, in the Northeast, larch caterpillar mainly damage larch and Korean pine, is China's Northeastern and pine forest the main insect pests in Inner Mongolia. Due to continuous feeding needles, two larva grow weak, make the tree cavities caused by dry pests occur, which led to the death, give a blockbuster larch trees forestry production brought huge economic losses. Therefore, the study of larch caterpillars occurrence regularity and prevention and control technology has very important practical significance.This paper studied larch caterpillar occurrence regularity, analyzing conclusion is as follows:(1) larch caterpillar in ownership is two years happened with generation in Dailing district, actual across three year, larvae nine years old, larch caterpillar eggs prolific pine needles or release of the small branches, and hatching larvae when releasing eggs shell bite open then crawled out, hatch hole more for doesn't furl neatly and larvae climbed out after feeding egg shell habit continued larch caterpillars, mainly in 4 ~ 8 hatch the eggs hatch, normal fertilization rates generally about 90%. The average adult life for larch caterpillar 6d left and right sides, female insect life slightly higher than male worm.(2) with the ownership Dailing larch caterpillar sex ratio for♀: came = 1.06:1. Sex ratio (came)♀: basic thereabouts, and female insect slightly more than male worm, reflecting the environment is superior, also show the worm in the regional developing normally, there are further development trend. In 2007 and 2008 and 2009 larch caterpillar each age level of individual number of live there exist obvious differences can be analyzed into 2009 larch caterpillar will be large happen. Through each age level larva individual distribution analysis, can predict early next year, whether big happened larch caterpillar for early protective measures are provided scientific basis. Larch caterpillar in different development stages, the spatial distribution pattern varies significantly.(3) larch caterpillars occurrence and climatic conditions have close relations, and warm arid climate conducive to larch caterpillar growth and development, on the other hand warm arid climate can make acerola biological chemical composition change, an increase of larvae of nutrition, improve pests survival. Larch caterpillar female insect spawning quantity with univariate vary.(4) larch caterpillar happen severity is influenced by environmental constraints of the stand, so we can through investigation, the benefit of larch caterpillar serious occurrence of forestland, as the key inspection object. Also find those with unfavorable to the forest larch caterpillar big happened, don't put it on monitoring point so that we can set priorities and rational use of manpower and material resources to avoid unnecessary waste. On the other hand, we also can be in forestry measures to prevent or reduce fluctuation kongfu larch caterpillar occurring conditions, in order to achieve the purpose of natural control. If appropriate closing hillsides to facilitate afforestation in human activities appropriate to keep largish crown density (such as crown density not less than 0.7) and retention of a certain number of hardwood etc.(5) artificially picking LuanKuai and pupa can effectively control larch caterpillar happen. Black lights and frequency vibration light traping moth effect compared, black lights is slightly better than frequency vibration lamp. Only after judging from prevention effect, black lights better than frequency vibration lamp, especially the lamp prevention outstandingly. Hanging nest box to control larch caterpillar obvious effect, can restrain the development of larch caterpillar population. |
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