International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya; North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa.
North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa.
Microb Pathog. 2019 Jun;131:197-204. doi: 10.1016/j.micpath.2019.04.010. Epub 2019 Apr 10.
The compatibility of the entomopathogenic fungus Metarhizium anisopliae ICIPE 30 which was proved to be pathogenic to adult Spoladea recurvalis, and phenylacetaldehyde (PAA) floral attractant for lepidopteran moths, was investigated under laboratory and field conditions through spatial and temporal separations. Horizontal transmission of M. anisopliae ICIPE 30 between adult S. recurvalis and the number of conidia picked up by a single moth from the autoinoculation device were also determined under laboratory tests. When freshly emerged moths were inoculated with fungal conidia ("donors") and maintained together with an equal number of untreated freshly emerged moths ("recipients") in the laboratory, they were able to transmit infection to untreated moths resulting to 76.9% mortality with an LT value of 6.9 days. The quantity of conidia a moth could acquire and retain from the autoinoculation device in the laboratory was assessed at 0, 24, 48, and 72 h post-inoculation. The overall mean number of conidia acquired by a single moth was significantly higher immediately after exposure (0 h) (14.3 ± 2.5 × 10) than at 24, 48, and 72 h after inoculation (F = 10.26, Df = 3,8, P = 0.003), though a single moth still retained 4.6 ± 0.9 × 10 conidia 72 h post inoculation. Laboratory results showed that PAA completely inhibited the germination of the conidia 8 days post exposure, while the conidial viability was not affected in the control treatment without PAA. Under field conditions, the inhibitory effects of PAA on conidial germination was minimized by placing it at a distance of 5-10 cm from M. anisopliae isolate ICIPE 30 conidia. There was no significant difference in conidial germination in the control treatment and in treatments where PAA was placed at 5 cm and 10 cm away from M. anisopliae isolate ICIPE 30. Conidial germination was low in the autoinoculation device that had PAA directly exposed to the fungus. PAA is therefore compatible with M. anisopliae ICIPE 30 for use in integrated management of S. recurvalis, if spatially separated 5 cm away from the fungus and could thus be combined in an autocontamination devices for the control of S. recurvalis.
在实验室和田间条件下，通过时空分离，研究了对成年 Spoladea recurvalis 具有致病性的昆虫病原真菌绿僵菌 ICIPE 30 与苯乙醛（PAA）花引诱剂对鳞翅目飞蛾的相容性。还通过实验室测试确定了成年 S. recurvalis 之间 M. anisopliae ICIPE 30 的水平传播以及一只飞蛾从自动接种装置中采集的分生孢子数量。当刚羽化的飞蛾被真菌分生孢子（“供体”）接种并与数量相等的未经处理的刚羽化的飞蛾（“受体”）一起在实验室中饲养时，它们能够将感染传播给未经处理的飞蛾，导致 76.9%的死亡率，LT 值为 6.9 天。在实验室中，评估了飞蛾在接种后 0、24、48 和 72 小时从自动接种装置中获得和保留的分生孢子的数量。一只飞蛾在暴露后立即（0 小时）获得的分生孢子总数明显高于 24、48 和 72 小时后接种时（F=10.26，df=3，8，P=0.003），尽管一只飞蛾在接种后 72 小时仍保留 4.6±0.9×10 个分生孢子。实验室结果表明，PAA 在暴露后 8 天完全抑制了分生孢子的萌发，而在没有 PAA 的对照处理中，分生孢子的活力没有受到影响。在田间条件下，通过将 PAA 放置在距绿僵菌分离株 ICIPE 30 分生孢子 5-10 厘米处，可最大程度地减少 PAA 对分生孢子萌发的抑制作用。在对照处理中和 PAA 分别放置在距绿僵菌分离株 ICIPE 30 5 厘米和 10 厘米处的处理中，分生孢子的萌发没有明显差异。在自动接种装置中，分生孢子的萌发率较低，PAA 直接暴露于真菌中。因此，如果与真菌间隔 5 厘米，PAA 与绿僵菌 ICIPE 30 兼容，可用于 S. recurvalis 的综合管理，并且可以将其组合在用于控制 S. recurvalis 的自动污染装置中。
