Physiological constraints restrict specialist pathogens from infecting new hosts. From an applied perspective, a narrow host range makes specialist pathogens interesting for targeting specific pest insects since they have minimal direct effects on non-target species. Entomopathogenic fungi of the genus Entomophthora are dipteran-specific but have not been investigated for their ability to infect the spotted wing drosophila (SWD; Drosophila suzukii) a fruit-damaging pest invasive to Europe and America. Our main goal was to study whether SWD is in the physiological host range of the entomophthoralean species E. muscae. We investigated pathogenicity and virulence of E. muscae towards its main natural host, the housefly Musca domestica, and towards SWD. We found that E. muscae readily infected and significantly reduced survival of SWD by 27.3% with the majority of flies dying 4–8 days post-exposure. In comparison with SWD, infection of the natural host M. domestica resulted in an even higher mortality of 62.9% and larger conidial spores of E. muscae, reflecting the physiological constraints of the pathogen in the atypical host. We demonstrated that pathogens of the E. muscae species complex that typically have a narrow natural host range of one or few dipteran species are able to infect SWD, and we described a new method for in vivo transmission and infection of an entomophthoralean fungus to SWD.

中文翻译：

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铃木果蝇用专性昆虫病原真菌小食虫昆虫（Entomophthora muscae）感染。

生理限制限制了专门病原体感染新宿主。从应用的角度来看，狭窄的寄主范围使专门病原体对于靶向特定的害虫具有吸引力，因为它们对非目标物种的直接影响极小。属的昆虫病原真菌虫是双翅目特异性，但尚未追究其感染的斑翅果蝇的能力（SWD;果蝇suzukii）水果破坏性害虫侵入到欧洲和美国。我们的主要目的是研究SWD是否在食虫物种麝香（E. muscae）的生理寄主范围内。我们调查了E. muscae对它的主要天然宿主家蝇的致病性和毒力。家蝇和对社署。我们发现，E。muscae很容易被感染，并且使大部分果蝇在接触后4-8天死亡，从而使SWD的存活率降低了27.3％。与SWD相比，天然宿主的感染家蝇导致了62.9％甚至更高的死亡率和较大的分生孢子的孢子E. muscae，反映了非典型宿主病原体的生理限制。我们证明了通常具有一个或几个二萜物种的狭窄自然寄主范围的E. muscae物种复合物的病原体能够感染SWD，并且我们描述了一种体内传播和消化食虫性真菌到SWD的新方法。