Infection of Drosophila suzukii with the obligate insect-pathogenic
fungus Entomophthora muscae
Paul G. Becher
Rasmus E. Jensen
Myrsini E. Natsopoulou
Henrik H. De Fine Licht
Received: 30 May 2017 / Revised: 21 August 2017 / Accepted: 31 August 2017 / Published online: 9 September 2017
Ó The Author(s) 2017. This article is an open access publication
Abstract Physiological constraints restrict specialist
pathogens from infecting new hosts. From an applied
perspective, a narrow host range makes specialist patho-
gens 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; Dro-
sophila 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, infec-
tion 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 ento-
mophthoralean fungus to SWD.
Keywords Entomopathogen Á Fly Á Fungal pathogen Á
Insect pest Á Spotted wing drosophila
• Dipteran-speciﬁc pathogens are potential agents to
control the fruit-damaging Drosophila suzukii.
• This is the ﬁrst report of the obligate insect-pathogenic
fungus Entomophthora muscae being able to infect and
kill male and female D. suzukii.
• An even higher virulence towards the natural host
Musca domestica and differences in spore morphology
may reﬂect physiological constraints of the tested E.
muscae isolate when infecting D. suzukii.
• Entomophthora species like the dipteran-speciﬁc E.
muscae have a potential for biological control of D.
The Asian spotted wing drosophila (SWD; Drosophila
suzukii) is an invasive and serious economic pest in fruit
and berry. Since growers became aware of a SWD invasion
in Southern Europe and the Eastern USA in 2008, the ﬂy
Communicated by A. Biondi.
& Paul G. Becher
& Henrik H. De Fine Licht
Chemical Ecology Unit, Department of Plant Protection
Biology, Swedish University of Agricultural Sciences,
Box 102, 23053 Alnarp, Sweden
Section for Organismal Biology, Department of Plant and
Environmental Sciences, University of Copenhagen,
Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
Section for Entomology and Plant Pathology, Department of
Agroecology, Aarhus University, Forsøgsvej 1,
4200 Slagelse, Denmark
J Pest Sci (2018) 91:781–787