TitleDisrupting butterfly caterpillar microbiomes does not impact their survival and development.
Publication TypeJournal Article
Year of Publication2019
AuthorsPhalnikar K, Kunte K, Agashe D
JournalProc Biol Sci
Volume286
Issue1917
Pagination20192438
Date Published2019 Dec 18
ISSN1471-2954
Abstract

Associations with gut microbes are believed to play crucial roles in the physiology, immune function, development and behaviour of insects. However, microbiome sequencing has recently suggested that butterflies are an anomaly, because their microbiomes do not show strong host- and developmental stage-specific associations. We experimentally manipulated butterfly larval gut microbiota and found that disrupting gut microbes had little influence on larval survival and development. Larvae of the butterflies and that fed on chemically sterilized or antibiotic-treated host plant leaves had significantly reduced bacterial loads, and their gut bacterial communities were disrupted substantially. However, neither host species treated this way suffered a significant fitness cost: across multiple experimental blocks, treated and control larvae had similar survival, growth and development. Furthermore, re-introducing microbes from the excreta of control larvae did not improve larval growth and survival. Thus, these butterfly larvae did not appear to rely on specialized gut bacteria for digestion, detoxification, biomass accumulation and metamorphosis. Our experiments thus show that dependence on gut bacteria for growth and survival is not a universal phenomenon across insects. Our findings also caution that strategies which target gut microbiomes may not always succeed in controlling Lepidopteran pests.

DOI10.1098/rspb.2019.2438
Alternate JournalProc. Biol. Sci.
PubMed ID31847770