Biocontrol agents (BCAs) are commonly sprayed on flowering pipfruit trees to prevent them from getting infected by various pathogens. By entomovectoring, BCAs can be directly delivered onto the flowers. However, we currently lack knowledge on the distribution dynamics of BCAs by pollinators. Here, managed bees, both bumble bees (Bombus terrestris) and mason bees (Osmia bicornis and Osmia cornuta), were placed in the vicinity of flowering pipfruit trees (pear ‐‘Conference’, and apple—‘Svatava’ and ‘Jonagold’), and this allowed us to investigate the distribution of a model BCA, namely, Serenade® MAX, from spray‐inoculated flowers of a centralized tree to non‐inoculated flowers of surrounding receiver trees by bees in an experimental setup in outdoor conditions. One hour after inoculation, we detected an enrichment of BCA in the flowers of the receiver trees and this for each tested pipfruit. The distribution of BCA from treated to untreated flowers was homogenous between the receiver trees for ‘Svatava’, while significantly different loads were detected for both ‘Conference’ and ‘Jonagold’, which might be due to differences in environmental factors, and/or bee characteristics. More research is needed to understand the distribution dynamics of BCAs by pollinators in field conditions, such as in commercial orchards or crop fields, and how this could result in an efficient control.

中文翻译：

---

梅森蜜蜂和大黄蜂在苹果和梨中分布模型生物防治剂 (Serenade® MAX)

生物防治剂 (BCA) 通常喷洒在开花的核果树上，以防止它们被各种病原体感染。通过昆虫载体，BCAs 可以直接传递到花朵上。然而，我们目前缺乏关于传粉媒介 BCA 分布动态的知识。在这里，管理蜜蜂，包括大黄蜂（Bombus terrestris）和梅森蜜蜂（Osmia bicornis 和 Osmiacornuta），被放置在开花的核果树（梨 -'Conference' 和苹果 -'Svatava' 和 'Jonagold'）附近，这使我们能够在室外条件下的实验设置中研究模型 BCA 的分布，即 Serenade® MAX，从集中树的喷雾接种花到蜜蜂周围接收树的未接种花。接种后一小时，我们在接收树的花朵中检测到 BCA 的富集，并且对于每个测试的核果来说都是如此。从处理到未处理的花的 BCA 分布在“Svatava”的接收树之间是同质的，而“会议”和“Jonagold”的负载量显着不同，这可能是由于环境因素和/或蜜蜂的差异特征。需要更多的研究来了解传粉者在田间条件下（例如商业果园或农田）的 BCA 分布动态，以及这如何导致有效控制。这可能是由于环境因素和/或蜜蜂特征的差异造成的。需要更多的研究来了解传粉者在田间条件下（例如商业果园或农田）的 BCA 分布动态，以及这如何导致有效控制。这可能是由于环境因素和/或蜜蜂特征的差异造成的。需要更多的研究来了解传粉者在田间条件下（例如商业果园或农田）的 BCA 分布动态，以及这如何导致有效控制。