Tuta absoluta (tomato leafminer) is one of the devastating agricultural pest that attack mainly tomatoes. The continuous use of chemical pesticides is not affordable and poses a collateral damage to human and environmental health. This requires integrated pest management to reduce chemical pesticides. B. thuringiensis is a cosmopolitan, antagonistic soil bacterium used to control agricultural pests. In this study, effective Bt strains were screened from different sample sources based on their lepidopteran specific cry genes and larvicidal efficacy against tomato leafminer, T. absoluta under laboratory conditions. Of the 182 bacterial isolates, 55 (30 %) of isolates harbored parasporal protein crystals. Out of these, 34 (62 %) isolates possess one or more lepidopteran specific cry genes: 20 % of isolates positive for cry2, 18.2 % for cry9, 3.6 % for cry1, 16.4 % for cry2 + cry9, 1.8 % for cry1 + cry9, and 1.8 % for cry1 + cry2 + cry9. However, 21 (38.2 %) isolates did not show any lepidopteran specific cry genes. Isolates positive for cry genes showed 36.7–75 % and 46.7–98.3 % mortality against second and third instar larvae of the T. absoluta at the concentration of 10⁸ colony forming units (CFUs) ml⁻¹. Cry1 and cry1 plus other cry gene positive isolates were relatively more pathogenic against T. absoluta. However, third instar larvae of the T. absoluta was more susceptible than second instar larvae. Two of the isolates, AAUF6 and AAUMF9 were effective and scored LT₅₀ values of 2.3 and 2.7 days and LC₅₀ values of 3.4 × 10³ and 4.15 × 10³ CFUs ml⁻¹ against the third instar larvae, respectively. The phylogenetic studies showed some congruence of groups with cry gene profiles and lethality level of isolates and very interestingly, we have detected a putative new phylogenetic group of Bt from Ethiopia.

Tuta absoluta（番茄潜叶虫）是主要攻击番茄的破坏性农业害虫之一。化学杀虫剂的持续使用是负担不起的，并且会对人类和环境健康造成附带损害。这需要综合虫害管理以减少化学农药。B. thuringiensis是一种世界性的拮抗土壤细菌，用于控制农业害虫。在本研究中，基于鳞翅目特定的cry基因和对番茄潜叶潜蝇T. absoluta 的杀幼虫功效，从不同的样品来源中筛选出有效的Bt菌株在实验室条件下。在 182 个细菌分离株中，55 个 (30%) 分离株含有副孢子蛋白晶体。这些中，34（62％）分离物具有一种或多种鳞翅目特异性哭基因：分离阳性的20％CRY2，18.2％cry9，为3.6％的cry1，为16.4％CRY2 + cry9，1.8％的cry1 + cry9，和 1.8% 为cry1 + cry2 + cry9。然而，21 个 (38.2 %) 分离株没有显示任何鳞翅目特定的哭泣基因。隔离阳性哭在 10 ⁸集落形成单位 (CFU) ml ^-1的浓度下，T.基因对 T. absoluta 的二龄和三龄幼虫的死亡率分别为 36.7-75% 和 46.7-98.3% 。Cry1和cry1加上其他cry基因阳性分离株对T. absoluta 的致病性相对更强。然而，T. absoluta 的三龄幼虫比二龄幼虫更易感。两个分离株，AAUF6 和 AAUMF9 是有效的，LT ₅₀值为 2.3 和 2.7 天，LC ₅₀值为 3.4 × 10 ³和 4.15 × 10 ³ CFUs ml ^-1分别对抗三龄幼虫。系统发育研究显示了一些具有cry基因谱和分离株致死水平的组的一致性，非常有趣的是，我们检测到了一个来自埃塞俄比亚的推定的新的Bt系统发育组。