RT Journal Article
SR Electronic
T1 The Gut-Associated Microbiome of the Eastern Spruce Budworm Does Not Influence Larval Growth or Survival
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 330928
DO 10.1101/330928
A1 Melbert T. Schwarz
A1 Daniel Kneeshaw
A1 Steven W. Kembel
YR 2018
UL http://biorxiv.org/content/early/2018/05/25/330928.abstract
AB Microbial communities have been shown to play an important role for host health in mammals, especially humans. It is thought that microbes could play an equally important role in other animal hosts such as insects. A growing body of evidence seems to support this, however most of the research effort in understanding host-microbe interactions in insects has been focused on a few well-studied groups such as bees and termites. We studied the effects of the gut-associated microbial community on the growth of the eastern spruce budworm Choristoneura fumiferana, an economically important lepidopteran forest pest in eastern Canada and the northeastern United States. Contrary to our expectations, although antibiotics influenced spruce budworm microbial community structure, the gut microbial community of spruce budworm larvae did not influence host growth or survival. Our results agree with the hypothesis that lepidopteran larvae lack resident microbial communities and are not nutritionally dependent on bacterial symbionts. However, while most bacteria originating on foliage appear to be transient through the gut and could not be linked with host growth, some bacteria may thrive better in the C. fumiferana gut.IMPORTANCE The importance of bacterial symbiosis has been clearly shown in humans. This has led to a number of studies looking for similar levels of dependence on microbial communities for host health in other organisms. The eastern spruce budworm (Choristoneura fumiferana) is an economically important lepidopteran forest pest that feeds on the hard to digest needles of balsam fir and spruce trees making it an ideal candidate for studying host-microbe interactions. We found that disturbance of the gut microbiome with antibiotic treatment did not significantly affect the growth of C. fumiferana larvae and the majority of bacteria in the C. fumiferana gut were more abundant in diet samples. Our findings generally support the recent hypothesis that lepidopteran larvae lack resident microbiota, however we also show that some rare taxa increase in relative abundance in the gut suggesting weak selective pressures are at play in the larval C. fumiferana gut.