估计粉虱若虫存活数量的新方法——氧化镁薄板法

介绍一种估计粉虱若虫存活数的简易方法。粉虱若虫分泌的蜜露滴落在氧化镁薄板上后形成清晰的圆坑,在体视显微镜下易于观察和计数,在确定粉虱若虫数量(Nd)和平均蜜露数(Nn)存在线性相关后,相应得出若虫数量评估因子(NEF)=Nn/Nd,提出通过蜜露数和若虫数量评估因子估算若虫数量的方法。在蕃茄叶片上,烟粉虱Bemisia tabaci(Gennadius)1~2龄若虫、3~4龄若虫和温室白粉虱Trialeurodes vaporariorum(Westwood)1~2龄若虫、3~4龄若虫的数量评估因子NEF分别为7·73,5·69,5·18和5·03。应用该方法检测吡虫啉对粉虱的毒力,并与传统方法进行比较,两者没有显著差异,而且该方法更简便准确。

Using magnesium oxide-glass slide method to estimate survival amount of whitefly nymphs

In this paper, a simple method was developed for Honeydew droplets of nymphs may form clear round holes on estimating the amount of surviving whitefly nymphs. magnesium oxide glass slide, which could be easily observed and counted under stereomicroscope. After the linear correlation relationship between number of nymphs （Nn） and number of droplets（Nd） was determined, nymph estimate factor（NEF） was accordingly determined, and a method of counting nymphs was proposed based on number of droplets and NEF. On tomato leaves, the NEF of 1st - 2nd instar nymph, 3rd-4th instar nymph of Bemisia tabaci, （Gennadius） and the NEF of 1st-2nd instar nymph, 3rd-4th instar nymph of Trialeurodes vaporariorum （Westwood） are 7.73,5.69, 5.18 and 5.03, respectively. Toxicity of acetamiprid to whiteflies was studied with this method. No significant difference was detected between the magnesium oxide glass slide method and the traditional method. Nevertheless the new method was more simple and exactly than the traditional method for counting survival nymphs.