Shililu J I, Tewolde G M, Brantly E, Githure J I, Mbogo C M, Beier J C, Fusco R, Novak R J
National Malaria Control Program, Division of Comunicable Diseases Control, Ministry of Health, PO Box 12, Asmara, Eritrea.
J Am Mosq Control Assoc. 2003 Sep;19(3):251-8.
We evaluated the larvicidal activity of the granular formulation of Bacillus thuringiensis israelensis (Bti) serotype H-14 (Vectobac G, 200 ITU/mg) and Bacillus sphaericus (Bsph) serotype H5a5b (Vectolex CG, 670 Bs ITU/mg) against Anopheles arabiensis and other mosquitoes in breeding habitats in 3 sites, Gash-Barka, Anseba, and Debub zones, in Eritrea. The primary objective was to determine the optimal application rate and duration of effect for Bti and Bsph in representative larval habitats as compared with the organophosphate temephos. The biolarvicides were tested at 100% (high) and 50% (low) of the maximum recommended application rate. Temephos was applied at a rate of 100 ml/ha. At least 4 replicate experiments with Vectobac G (5.6 and 11.2 kg/ha), Vectolex CG (11.2 and 22.4 kg/ha) were conducted in each study site. All 3 larvicides caused significant mortality of the main malaria vector species, An. arabiensis, and other mosquito species (Anopheles cinereus, Anopheles pretoriensis, Culex quinquefasciatus). The larvicidal activity for Bti and Bsph was variable depending upon breeding habitat, mosquito species, and general ecology of the area. Both biopesticides had a similar duration of activity (2-3 wk) and were generally as effective as temephos for these time periods. In some cases, the high and low application rates for Bti and Bsph produced equivalent control over 2-3 wk. The 2 Bacillus biopesticides were less effective in habitats with high algal content and in fast flowing streams primarily because of the inability to penetrate algal mats and dilution effect, respectively. The results show that application of the 2 biolarvicides bimonthly to streambed pools, rain pools, and similar habitats would maintain control of the anopheline mosquito population.
我们评估了苏云金芽孢杆菌以色列亚种（Bti）H - 14血清型（Vectobac G，200国际毒力单位/毫克）和球形芽孢杆菌（Bsph）H5a5b血清型（Vectolex CG，670球形芽孢杆菌国际毒力单位/毫克）颗粒制剂对厄立特里亚加什-巴尔卡、安塞巴和德布卜地区3个地点孳生地中的阿拉伯按蚊及其他蚊虫的杀幼虫活性。主要目的是确定与有机磷农药双硫磷相比，Bti和Bsph在代表性幼虫孳生地中的最佳施用量和药效持续时间。生物杀幼虫剂以最大推荐施用量的100%（高剂量）和50%（低剂量）进行测试。双硫磷的施用量为100毫升/公顷。在每个研究地点，对Vectobac G（5.6和11.2千克/公顷）、Vectolex CG（11.2和22.4千克/公顷）至少进行了4次重复实验。所有3种杀幼虫剂均导致主要疟疾传播媒介物种阿拉伯按蚊以及其他蚊虫物种（灰按蚊、 Pretoriensis按蚊、致倦库蚊）的大量死亡。Bti和Bsph的杀幼虫活性因孳生地、蚊虫种类以及该地区的总体生态环境而异。两种生物农药的活性持续时间相似（2 - 3周），并且在这些时间段内总体上与双硫磷的效果相当。在某些情况下，Bti和Bsph的高剂量和低剂量在2 - 3周内产生了等效的防治效果。这两种芽孢杆菌生物农药在藻类含量高的生境和水流湍急的溪流中效果较差，主要原因分别是无法穿透藻垫和稀释作用。结果表明，每两个月向河床水池、雨水池及类似生境施用这两种生物杀幼虫剂，可维持对按蚊种群的控制。
