Data from: Compatibility of the fungus Beauveria bassiana and Trichoplusia ni SNPV against the cabbage looper Trichoplusia ni : crop plant matters

BACKGROUND: Microbial insecticides are an important weapon in insect pest
management, but their use is still relatively limited. One approach for
increasing their efficacy and use could be to combine different pathogens
to increase pest mortality. However, little is known about whether
increasing pathogen diversity will improve pest management. Here, we
investigated the compatibility of two pathogens for the management of the
cabbage looper, Trichoplusia ni; T. ni nucleopolyhedrovirus (TniSNPV) and
the entomopathogenic fungus Beauveria bassiana on two crops, tomato and
broccoli. The pathogens were applied to individual plants using ultra low
volume sprays, alone or in combination, either synchronously or
asynchronously. Healthy 3rd instar T. ni larvae were introduced to the
plants before application and collected by destructive sampling 24h after
the last pathogen application. RESULTS: Combined applications did not
result in an increase in larval mortality compared to TniSNPV alone,
although mortality was generally high. Beauveria bassiana was considerably
less effective on broccoli compared to tomato. In both the combined
treatments, virus-induced mortality was approximately 50% lower when
applied together with the fungus, while fungus-induced mortality was not
affected by the virus, even when the virus was introduced 24h before the
fungus. CONCLUSION: While our results suggest that applying this
combination of entomopathogens would not be beneficial for pest
management, this study illustrates the need to consider the target crop as
an important driver of the efficacy of both single and mixed pathogen
applications in the field.

研究背景：微生物杀虫剂（microbial insecticides）是害虫治理的重要手段，但其应用仍相对有限。提升其药效与应用范围的可行途径之一，是联合使用不同病原物以提高害虫死亡率。然而，学界对于提升病原物多样性是否能改善害虫治理效果仍知之甚少。本研究针对甘蓝尺蠖（Trichoplusia ni）的治理，探究了两种病原物的相容性：粉纹夜蛾核型多角体病毒（TniSNPV）与昆虫病原真菌球孢白僵菌（Beauveria bassiana），试验分别在番茄与西兰花两种作物上开展。研究采用超低容量喷雾法，将病原物施用于单株植株，采用单独或联合的方式，联合施用又分为同步与异步两种模式。施药前将健康的3龄甘蓝尺蠖幼虫接入植株，于最后一次病原物施药后24小时通过破坏性取样收集幼虫。
研究结果：与单独施用TniSNPV相比，联合施用并未提升幼虫死亡率，尽管整体死亡率本就处于较高水平。球孢白僵菌在西兰花上的防治效果显著低于番茄。在两种联合施用处理中，与真菌联合施用时病毒诱导的死亡率均较单独施用病毒时降低约50%；而无论病毒是否提前24小时施用，真菌诱导的死亡率均未受病毒影响。
研究结论：尽管本研究结果表明，联合施用这两种昆虫病原物对害虫治理并无增益，但本研究凸显了需将目标作物作为田间单病原物与混合病原物施用药效的重要影响因子的必要性。