The South American tomato leafminer, Tuta absoluta (Meyrick 1917) (Lepidoptera: Gelechiidae), is a newly introduced and a major threat of tomato production in Ethiopia. Laboratory bioassay was conducted to evaluate locally isolated Metarhizium anisopliae (Metsch.) (Sorokin), against larvae of T. absoluta. Twenty-five Metarhizium isolates were isolated from different soil types, using the great wax moth, Galleria mellonella L. baiting method. From these, 13 isolates were prescreened by biological efficiency index model and tested against 2nd and 3rd larval instars of T. absoluta at the concentration of 107 spores ml−1. Sterile water plus Tween 80 (0.1% v/v) was used as a control. Greenhouse reared larvae of T. absoluta were used as experimental organisms. All tested Metarhizium formulations were pathogenic to T. absoluta in all conducted bioassays. Three isolates, AAUM78, AAUM39, and AAUM76, were the most effective and scored 88, 90, and 95% and 90, 93.3, and 95.7% mortality against 2nd and 3rd larval instars of T. absoluta, respectively. The lowest (48.5 and 50%) mortality rate was recorded by isolate AAUM30 against 2nd and 3rd larval instars, respectively, in 7 days post inoculation. However, all isolates showed significant statistical differences with F (24, 50) = 6.825, p < 0.001 and F (23, 15) = 3.97, p < 0.001 of mortality to 2nd and 3rd larval instars, respectively. Molecular analysis categorized these selected isolates under species of M. anisopliae and grouped into 2 different groups. AAUM78 and AAUM39 were recorded LT50 values of 3.93 and 3.5 days at the lowest (104 spore ml−1) concentration and LC50 values of 1.2 × 103 and 2.9 × 103 spore ml−1, respectively. Although AAUM78 and AAUM39 were virulent to the target pest, further field evaluation is required to determine their potential efficacy for T. absoluta control.

中文翻译：

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埃塞俄比亚番茄变叶者Tuta absoluta（Meyrick 1917）（鳞翅目：Gelechiidae）的Metrahizium anisopliae天然分离株的形态，分子和致病性特征

南美番茄切叶机Tuta absoluta（Meyrick，1917年）（鳞翅目：Gelechiidae）是埃塞俄比亚的一种新近引进的番茄，对番茄生产构成重大威胁。进行了实验室生物测定，以评估当地分离的拟南芥（Metrhizium anisopliae，Metsch。）（Sorokin）对绝对黑麦草的幼虫。使用大蜡蛾，Galleria mellonella L.诱饵法从不同的土壤类型中分离出二十五个分离的金属根。从这些菌株中，通过生物学效率指数模型对13个分离株进行了预筛选，并在107孢子ml-1的浓度下对绝对黑穗实线虫的第二和第三幼虫进行了测试。无菌水加吐温80（0.1％v / v）用作对照。将T.absoluta的温室饲养的幼虫用作实验生物。在所有进行的生物测定中，所有测试的金属根制剂均对绝对黑麦草有致病性。最有效的三种分离株是AAUM78，AAUM39和AAUM76，它们分别针对绝对黑斑病菌第二和第三龄幼虫的死亡率分别为88％，90％和95％，90％，93.3％和95.7％。接种后7天内，分别针对第二龄和第三龄幼虫的AAUM30分离株，死亡率最低（分别为48.5和50％）。然而，所有分离株的F（24，50）= 6.825，p <0.001和F（23，15）= 3.97，p <0.001对第二龄和第三龄幼虫死亡率的统计学差异显着。分子分析将这些选定的分离物归类为分离的支链霉菌，并将其分为两个不同的组。AAUM78和AAUM39在最低（104孢子ml-1）浓度下记录的LT50值为3.93和3.5天，LC50值分别为1.2×103和2.9×103孢子ml-1。