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飞虱虫疠霉（Ｐａｎｄｏｒａ ｄｅｌｐｈａｃｉｓ（Ｈｏｒｉ） Ｈｕｍｂｅｒ）是我国稻区常见引发稻飞虱流行病的重要病原真菌。本研究用从稻飞虱虫尸上分离获得的两个飞虱虫疠霉菌株Ｆ９５１２７和Ｆ９５１２９分别对褐飞虱（Ｎｉｌｏｐａｒｖａｔａｌｕｇｅｎｓ Ｓｔａｌ）进行了毒力测定。将 ４－５龄若虫曝露在液体培养所获的产孢菌丝平板下进行“孢子浴”接种，通过控制孢子浴时间获得系列接种剂量。各剂量处理的若虫分别饲养于生长培养箱中，温度２５℃，光照１２Ｌ∶１２Ｄ，相对湿度接近饱和，逐日检查死亡数。所得数据很好地拟合时间－剂量－死亡率模型，由此获得用于估计毒力指标的时间和剂量效应参数。接种后 ６－８ ｄ， Ｆ９５１２９和 Ｆ９５１２７的 ＬＤ_（５０）分别为 ３２７、 １２２、４６孢子／ｍｍ~２和４０９、 １３３、 ７４孢子／ｍｍ~２， Ｆ９５１２７在９５孢子／ｍｍ~２剂量下的 ＬＴ_（５０）为７．６ｄ，而Ｆ９５１２９的ＬＴ_（５０）则从１７２孢子／ｍｍ~２时的 ６． ６ｄ下降到 ５２５孢子／ｍｍ~２时的５．６ｄ。根据所测毒力指标和剂量效应参数的分析比较，两个飞虱虫疠霉菌株对褐飞虱均具有中等毒力，且彼此间无显著差异。
Planthopper (Pandora delphacis (Hori) Humber) is an important pathogenic fungus that causes the planthopper epidemic in China. In this study, two strains of Botrytis cinerea, F95127 and F95129, isolated from pests of the rice planthopper, were used to determine the virulence of the brown planthopper (Niloparvatalugens Stal). 4-5 instar nymphs were exposed to spore-bath inoculation under sporulating filamentous plates obtained from liquid culture, and serial inoculation doses were obtained by controlling spore bath time. Each dose of nymphs were housed in a growth incubator at a temperature of 25 ℃, light 12L: 12D, the relative humidity close to saturation, the number of deaths checked daily. The data obtained well fit the time-dose-mortality model, from which time and dose-response parameters for estimating virulence indices were obtained. The LD50 of F95129 and F95127 were 327, 122, 46 spores / mm ~ 2 and 409, 133, 74 spores / mm ~ 2 at 6-8 days after inoculation, respectively. LT_ (50) is 7.6d, whereas for F95129 LT_ (50) is from 6 to 172 spores / mm ~ 2. 6d down to 525 spores / mm ~ 2 5.6d. Based on the analysis and comparison of the measured virulence parameters and dose-response parameters, both Botrytis cinerea strains were moderately toxic to N. lugens and showed no significant difference from each other.