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早稻的主要害虫有二化螟、三化螟、稻叶蝉(黑尾叶蝉)和稻纵卷叶螟。现将近年来摸索的不完整的预测预报及防治方法整理于下。 二化螟和三化螟 一、预测预报 1.发生量预测: (1)虫口密度 4月中旬查越冬后虫口密度,以预计第一代发生量。选有代表性的花草、三麦和油菜田各3—4块,花草田采用平行取样法,每块取250丛稻根;麦、菜田用多点取样,每块田取0.1亩土表稻根,剥查虫数,计算各类田的活虫虫口密度,并以加权平均法计算当地的越冬后虫口密度。6月中
The main pests of early rice are the Chilo suppressalis, rice borer, rice leafhopper (rice leafhopper) and rice leaf roller. Now in recent years to explore the incomplete prediction and forecasting methods and collated in the next. Chilo suppressalis and Chilo suppressalis I. Prediction and forecast 1. Occurrence amount forecast: (1) Insect population density In mid-April, the density of insect population after overwintering was surveyed to estimate the occurrence of the first generation. Select the representative flowers, three wheat and rape fields each 3-4 blocks, flowers and fields using parallel sampling method, each taking 250 rice roots; wheat, vegetable fields with multi-point sampling, each field take 0.1 acres of soil table Rice roots, stripping the number of insects, all kinds of fields to calculate the population density of live insects, and the weighted average local population over the winter after the population density. Mid-June