Department of Biology, Faculty of Sciences, Free University of Brussels, Brussels, Belgium.
Pest Manag Sci. 2011 Sep;67(9):1069-75. doi: 10.1002/ps.2147. Epub 2011 Mar 10.
Bombus terrestris L. bumblebees are widely used as commercial pollinators, but they might also be of help in the battle against economically important crop diseases. This alternative control strategy is referred to as pollinator-and-vector technology. The present study was designed to investigate the capacity of B. terrestris to fulfil this role in greenhouse strawberry flowers, which were manually inoculated with a major plant pathogen, the grey mould Botrytis cinerea Pers.: Fr. A model microbiological control agent (MCA) product Prestop-Mix was loaded in a newly developed two-way bumblebee dispenser, and, in addition, the use of the diluent Maizena-Plus (corn starch) was tested.
Importantly, loading of the MCA caused no adverse effects on bumblebee workers, with no loss of survival or impairment of flight activity of the workers during the 4 week flowering period. Secondly, vectoring of Prestop-Mix by bumblebees resulted in a higher crop production, as 71% of the flowers developed into healthy red strawberries at picking (preharvest yield) as compared with 54% in the controls. In addition, these strawberries were better protected, as 79% of the picked berries remained free of B. cinerea after a 2 day incubation (post-harvest yield), while this percentage was only 43% in the control. Overall, the total yield (preharvest × post-harvest) was 2-2.5 times higher than the total yield in the controls (24%) in plants exposed to bumblebees vectoring Prestop-Mix. Thirdly, the addition of the diluent Maizena-Plus to Prestop-Mix at 1:1 (w/w) resulted in a similar yield to that of Prestop-Mix used alone, and in no negative effects on the bumblebees, flowers and berries.
This greenhouse study provides strong evidence that B. terrestris bumblebees can vector a MCA to reduce B. cinerea incidence in greenhouse strawberries, resulting in higher yields. Similar yields obtained in the treatments with Prestop-Mix and Prestop-Mix + Maizena-Plus suggest an equally efficient dissemination of the biocontrol agent into the flowers with only half the initial concentration of Prestop-Mix, which illustrates the importance of the diluent.
熊蜂是一种广泛用于商业授粉的昆虫，但它们也可能有助于对抗经济上重要的作物病害。这种替代控制策略被称为传粉媒介和载体技术。本研究旨在调查熊蜂在温室草莓花中的这种作用的能力，这些草莓花是通过手动接种一种主要的植物病原体——灰霉病 Botrytis cinerea Pers.: Fr. 来接种的。一种新型的微生物控制剂（MCA）产品 Prestop-Mix 被加载到一种新开发的双向熊蜂分配器中，此外，还测试了稀释剂 Maizena-Plus（玉米淀粉）的使用。
重要的是，MCA 的加载对熊蜂工人没有造成任何不利影响，在 4 周的开花期内，没有工人死亡或飞行活动受损。其次，熊蜂传播 Prestop-Mix 导致作物产量更高，因为 71%的花在采摘时（收获前产量）发育成健康的红色草莓，而对照组为 54%。此外，这些草莓受到更好的保护，因为在采摘后 2 天的孵育期后，79%的采摘浆果仍然没有 B. cinerea，而对照组只有 43%。总的来说，暴露于传播 Prestop-Mix 的熊蜂的植物的总产量（收获前×收获后）比对照组（24%）高出 2-2.5 倍。第三，将稀释剂 Maizena-Plus 以 1:1（w/w）的比例添加到 Prestop-Mix 中，与单独使用 Prestop-Mix 相比，产量相似，对熊蜂、花朵和浆果均无不良影响。
本温室研究提供了强有力的证据，证明熊蜂可以传播 MCA 来降低温室草莓中 B. cinerea 的发病率，从而提高产量。在 Prestop-Mix 和 Prestop-Mix + Maizena-Plus 的处理中获得的相似产量表明，生物防治剂以初始 Prestop-Mix 浓度的一半同样有效地传播到花朵中，这说明了稀释剂的重要性。
