苏云金芽胞杆菌G033A对新发南美番茄潜叶蛾的室内毒力及田间防效

南美番茄潜叶蛾Tuta absoluta（Meyrick）是新近传入我国的一种世界毁灭性番茄害虫，对我国番茄产业的潜在威胁巨大。为有效控制南美番茄潜叶蛾，测定了新型苏云金芽胞杆菌基因工程菌G033A（Bt G033A）对该昆虫的室内毒力及田间防效。结果表明，在室内条件下，以32000 IU/mg Bt G033A WP处理过的番茄叶片饲喂南美番茄潜叶蛾幼虫，其室内毒力效果由高至底依次为4龄幼虫，3龄幼虫，1～2龄幼虫，致死中浓度LC₅₀分别为14.63、15.59和23.17 g/L；浓度在10 g/L及以上时，Bt G033A对南美番茄潜叶蛾各龄幼虫的毒力均较高，处理后96 h（第4 d）校正死亡率均超过90%。在田间条件下，以Bt G033A WP 100倍液（10 g/L）喷雾防治低龄幼虫即有较好的防效，药后第5 d对1龄和2龄幼虫的校正死亡率分别为89.1%和98.0%，药后第7 d对1龄和2龄幼虫的校正死亡率均为100%；并且，与常用的生物杀虫药剂鱼藤酮的防效相当。研究结果对有机蔬菜生产基地新发南美番茄潜叶蛾的有效控制及其综合防控方案制定，具有重要指导意义。

Laboratory Toxicity and Field Control Efficacy of Biopesticide Bacillus thuringiensis G033A on the South American Tomato Leafminer Tuta absoluta (Meyrick), a New Invasive Alien Species in China

The South American tomato leafminer Tuta absoluta (Meyrick), a world destructive tomato insect pest, is a new invasive alien species in China and has posed a potential threat to the Chinese tomato industry. To control T. absoluta effectively, the laboratory toxicity and field control efficacy of Bacillus thuringiensis G033A (Bt G033A, effective component, 32000 IU/mg), a newly developed bivalent genetically engineered bacteria, were evaluated using leaf dipping and field spraying methods, respectively. Laboratory toxicity was the highest on the 4^th instar larvae of T. absoluta, decreased in the 3^rd instars and further decreased in the 1^stto 2^nd instars, as indicated by LC₅₀ of 14.63, 15.59 and 23.17 g/L, respectively. Bt G033A had high control efficacy on T. absoluta larvae when the concentration of Bt G033A was 10 g/L or above, with a corrected mortality of over 90% at 96 h post treatment. On tomato plants grown in greenhouses, 100-fold diluents (10 g/L) of Bt G033A WP had high control efficacy on young larvae of T. absoluta. The corrected mortalities to the 1^st and 2^nd instars were 89.1% and 98.0%, respectively, on the fifth day after treatment and reached 100% on the seventh day after treatment. The insecticide activity of Bt G033A is comparable to that of 5% the Rotenone. The results can benefit the management of the South American tomato leafminer in organic vegetable production bases.