Diet breadth modulates preference - performance relationships in a phytophagous insect community

Maud Charlery De La Masselière,Benoît Facon,Pierre-François Duyck,Abir Hafsi

doi:10.1038/s41598-017-17231-2

Abstract

In most phytophagous insects, larvae are less mobile than adults and their fitness depends on the plant chosen by their mother. To maximize fitness, adult preference and larval performance should thus be correlated. This correlation is not always apparent and seems to increase with the level of specialisation, i.e. specialists have a stronger preference for high quality host plant species compared to generalists. The aim of this study was to test whether the relationship between female preference and larval performance was stronger for specialists than for generalists within a community of fruit flies (Diptera: Tephritidae). A total of six fruit fly species was used, including four generalists, and two specialists co-existing in La Reunion island (France). We estimated oviposition preference through the number of eggs laid and larval performance through the larval survival on 29 different host plants species belonging to 15 families in the laboratory and evaluated the relationship between these two traits. Preference-performance relationship differed according to the degree of specialisation with a strong positive correlation for specialists and no relationship for generalists. These results substantiate the theory that choosing high quality hosts is more important for specialists that are adapted to survive on fewer host plants than for generalists.

Highlights

Phytophagous insects comprise a substantial proportion of all described macro-organisms on earth with around five million described species[1]
We focused on the relationship between female preference and larval performance of six species of true fruit flies (Diptera: Tephritidae) belonging to the same community on the island La Réunion
Two species, Dacus demmerezi and Zeugodacus cucurbitae, feed mostly on the cucumber family (Cucurbitaceae)[27,28,29] and four species, Ceratitis catoirii, C. capitata, C. quilicii and Bactrocera zonata, feed on an average of 36 plants belonging to 17 different[27,30,31]. This community includes two native species (C. catoirii and D. demmerezi) and the other species successively invaded the island from Asia (Z. cucurbitae in 1972 and B. zonata in 2000) or Africa (C. capitata in 1939, C. quilicii in 1955)

Summary

Introduction

Phytophagous insects comprise a substantial proportion of all described macro-organisms on earth with around five million described species[1]. Specialists (i.e. species feeding on plants belonging to a single family) tend to show a stronger relationship between female preference and larval performance than generalists (i.e. species feeding on plants belonging to several families), because specialists have a higher fitness on a restricted host range[17]. We focused on the relationship between female preference and larval performance of six species of true fruit flies (Diptera: Tephritidae) belonging to the same community on the island La Réunion Within this community, two species, Dacus demmerezi and Zeugodacus cucurbitae (formerly known as Bactrocera cucurbitae [De Meyer, et al.26]), feed mostly on the cucumber family (Cucurbitaceae)[27,28,29] and four species, Ceratitis catoirii, C. capitata, C. quilicii (formerly known as Ceratitis rosa [De Meyer, et al.26]) and Bactrocera zonata, feed on an average of 36 plants (min: 16, max: 60) belonging to 17 different[27,30,31]. We compared our results between generalist and specialist species that share a common environment and take into account the degree of specialisation

Objectives

Methods

Results

Conclusion