Adult nutrition and butterfly fitness: effects of diet quality on reproductive output, egg composition, and egg hatching success.

Thorin L Geister,Klaus H Hoffmann,Klaus Fischer,Matthias W Lorenz

doi:10.1186/1742-9994-5-10

Thorin L Geister, Klaus H Hoffmann + Show 2 more

Open Access

https://doi.org/10.1186/1742-9994-5-10

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Abstract

BackgroundIn the Lepidoptera it was historically believed that adult butterflies rely primarily on larval-derived nutrients for reproduction and somatic maintenance. However, recent studies highlight the complex interactions between storage reserves and adult income, and that the latter may contribute significantly to reproduction. Effects of adult diet were commonly assessed by determining the number and/or size of the eggs produced, whilst its consequences for egg composition and offspring viability were largely neglected (as is generally true for insects). We here specifically focus on these latter issues by using the fruit-feeding tropical butterfly Bicyclus anynana, which is highly dependent on adult-derived carbohydrates for reproduction.ResultsAdult diet of female B. anynana had pronounced effects on fecundity, egg composition and egg hatching success, with butterflies feeding on the complex nutrition of banana fruit performing best. Adding vitamins and minerals to a sucrose-based diet increased fecundity, but not offspring viability. All other groups (plain sucrose solution, sucrose solution enriched with lipids or yeast) had a substantially lower fecundity and egg hatching success compared to the banana group. Differences were particularly pronounced later in life, presumably indicating the depletion of essential nutrients in sucrose-fed females. Effects of adult diet on egg composition were not straightforward, indicating complex interactions among specific compounds. There was some evidence that total egg energy and water content were related to hatching success, while egg protein, lipid, glycogen and free carbohydrate content did not seem to limit successful development.ConclusionThe patterns shown here exemplify the complexity of reproductive resource allocation in B. anynana, and the need to consider egg composition and offspring viability when trying to estimate the effects of adult nutrition on fitness in this butterfly and other insects.

Highlights

In the Lepidoptera it was historically believed that adult butterflies rely primarily on larval-derived nutrients for reproduction and somatic maintenance
In addition to reproductive output, here we investigate the effects of adult diet on egg composition and egg hatching success
While early fecundity was fairly similar across treatment groups, variation in late fecundity was higher with the banana and minerals and vitamins (MV) groups showing substantially higher values than all other groups

Summary

Introduction

In the Lepidoptera it was historically believed that adult butterflies rely primarily on larval-derived nutrients for reproduction and somatic maintenance. Fitness is composed of various components, such that determining individual fitness is a challenging enterprise Traits such as fecundity and/or egg size are used as proxies for individual fitness [1,4,5,6,7,8], while studies taking offspring survival into account appear to be much rarer [9,10,11,12,13]. In order to gain a more integrated understanding of reproductive resource allocation, we need to shed more light on the interplay between reserves originating from storage versus income, between diet quality and egg composition, and the associated consequences for offspring viability

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