Lewis M T, Koivunen E E, Swett C L, Hamby K A
Department of Entomology, University of Maryland, College Park, MD.
Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD.
Environ Entomol. 2019 Feb 13;48(1):68-79. doi: 10.1093/ee/nvy167.
The invasive vinegar fly, Drosophila suzukii Matsumura, has emerged as one of the most serious arthropod pests of primocane red raspberries (Rubus ideaus L.) in the United States. In raspberries, D. suzukii encounter a diverse community of microbes, including fruit rot pathogens such as Botrytis cinerea Pers and Cladosporium cladosporioides de Vries. In this study, our primary objectives were to evaluate D. suzukii-fungal associations and determine D. suzukii's influence on fungal communities in raspberry fruit. Through culture-based surveys of larval gut microbes, we isolated several yeast fungi (primarily Hanseniaspora spp.), as well as Cladosporium, Botrytis, and several other non-yeast fungi from larval frass, suggesting that D. suzukii larvae encounter and feed on these fungi. Subsequent field surveys confirmed that D. suzukii larvae occurred in berries affected by Botrytis fruit rot and Cladosporium fruit rot. Under laboratory conditions, D. suzukii may facilitate C. cladosporioides infections, likely through the introduction of epiphytic propagules on the fruit surface. We could not detect impacts on B. cinerea infections or establish a clear vectoring relationship for either fruit rot. These studies provide evidence for an association between D. suzukii and fungal fruit rot pathogens. Understanding interactions between raspberry fruit, D. suzukii, and fungal microbes-especially whether D. suzukii facilitates the development of fruit rots or conversely, if fruit rots influence D. suzukii infestation patterns-may improve pest and pathogen management programs.
入侵性果蝇——铃木氏果蝇（Drosophila suzukii Matsumura）已成为美国初结果红树莓（Rubus ideaus L.）最严重的节肢动物害虫之一。在树莓中，铃木氏果蝇会接触到各种各样的微生物群落，包括果实腐烂病原体，如灰葡萄孢（Botrytis cinerea Pers）和枝孢（Cladosporium cladosporioides de Vries）。在本研究中，我们的主要目标是评估铃木氏果蝇与真菌的关联，并确定铃木氏果蝇对树莓果实中真菌群落的影响。通过对幼虫肠道微生物进行基于培养的调查，我们从幼虫粪便中分离出了几种酵母真菌（主要是汉逊酵母属菌种），以及枝孢、葡萄孢和其他几种非酵母真菌，这表明铃木氏果蝇幼虫会接触并取食这些真菌。随后的田间调查证实，铃木氏果蝇幼虫出现在受葡萄孢果腐病和枝孢果腐病影响的浆果中。在实验室条件下，铃木氏果蝇可能会促进枝孢菌的感染，可能是通过在果实表面引入附生繁殖体。我们无法检测到对灰葡萄孢感染的影响，也无法确定这两种果腐病的明确传播关系。这些研究为铃木氏果蝇与真菌性果腐病原体之间的关联提供了证据。了解树莓果实、铃木氏果蝇和真菌微生物之间的相互作用——特别是铃木氏果蝇是否会促进果腐病的发展，或者相反，果腐病是否会影响铃木氏果蝇的侵染模式——可能会改善害虫和病原体管理方案。
