Luz C, Fargues J
Unité de Recherche en Lutte Biologique, INRA-Montpellier, Montferrier-sur-Lez, 34982, France.
J Invertebr Pathol. 1998 Sep;72(2):97-103. doi: 10.1006/jipa.1998.4774.
The epizootic potential of Beauveria bassiana for control of the triatomine vectors of Chagas' disease was investigated by studying the effects of both biotic and abiotic factors on the recycling of a highly virulent fungal isolate from fungus-killed cadavers of Rhodnius prolixus. The conidial production of B. bassiana from mummified cadavers of R. prolixus required high RH levels of at least 96.5% RH. At 97% RH and 25 degrees C, the amount of conidia per insect ranged from 5.3 x 10(6) (on first-instar larval cadavers) to 1.7 x 10(8) (on adult cadavers) depending on the size of the different stages of development of the host. Under optimal conditions, B. bassiana sporulation from R. prolixus cadavers took place in 4 to 5 days after death. At a high humidity level (97% RH) the intensity of the conidial production from Rhodnius cadavers was little affected by temperature over a range from 15 to 25 degrees C, but it declined at 28-30 degrees C and was null at 35 degrees C. There was only a weak influence of the blood meal of nymphs and its timing on the conidial production from B. bassiana-killed cadavers. The recycling capacity of different B. bassiana isolates, selected for their pathogenic activity to R. prolixus, did not differ. From a vector control standpoint, high humidity appears to be the most crucial climatic constraint. The recycling ability of B. bassiana on fungus-killed R. prolixus might contribute to the regulation of triatomine vectors only after applications during the rainy seasons.
通过研究生物和非生物因素对从被真菌杀死的红带锥蝽尸体中回收的高毒力真菌分离株再循环的影响，调查了球孢白僵菌对恰加斯病锥蝽传播媒介的 epizootic 潜力。从红带锥蝽木乃伊化尸体中产生球孢白僵菌分生孢子需要至少 96.5% RH 的高相对湿度水平。在 97% RH 和 25 摄氏度下，每只昆虫的分生孢子数量根据宿主不同发育阶段的大小，从 5.3×10⁶（一龄幼虫尸体上）到 1.7×10⁸（成虫尸体上）不等。在最佳条件下，球孢白僵菌从红带锥蝽尸体上的孢子形成在死亡后 4 至 5 天发生。在高湿度水平（97% RH）下，红带锥蝽尸体分生孢子产生的强度在 15 至 25 摄氏度范围内受温度影响较小，但在 28 - 30 摄氏度时下降，在 35 摄氏度时为零。若虫的血餐及其时间对球孢白僵菌杀死的尸体上分生孢子产生的影响较弱。选择对红带锥蝽具有致病活性的不同球孢白僵菌分离株的再循环能力没有差异。从病媒控制的角度来看，高湿度似乎是最关键的气候限制因素。球孢白僵菌在被真菌杀死的红带锥蝽上的再循环能力可能仅在雨季应用后才有助于锥蝽传播媒介的调控。
