Mating behaviour, mate choice and female resistance in the bean flower thrips (Megalurothrips sjostedti)

Adeyemi O Akinyemi,David K Mfuti,Tom W Pope,Amanuel Tamiru,William D J Kirk,Sevgan Subramanian

doi:10.1038/s41598-021-93891-5

Abstract

Many species of thrips (Thysanoptera) in the family Thripidae form mating aggregations, but the adaptive significance of these aggregations and the extent of male and female mate choice is poorly understood. We studied the mating behaviour of the bean flower thrips Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), which forms male aggregations and occurs across sub-Saharan Africa. We tested whether males choose mates by female age or mating status. No-choice mating bioassays with one male and one female were used to simulate the way males usually encounter only one female at a time in aggregations in the field. Virgin females violently resisted mating attempts by males, but we found no compelling evidence to establish whether this was indiscriminate or was screening suitable males. Younger males (1–2 days old) did not discriminate females by age (1–2 or 7–10 days old), but older males (7–10 days old) avoided mating with older females. Any male choice by female mating status (virgin or mated) was weak or absent. The mating behaviour of M. sjostedti shows broad similarities with that of other thrips species that form aggregations, but also shows some distinct and novel differences, which can help our understanding of the adaptive significance of aggregations.

Highlights

Many species of thrips (Thysanoptera) in the family Thripidae form mating aggregations, but the adaptive significance of these aggregations and the extent of male and female mate choice is poorly understood
An understanding of mating behaviour and mate choice is important because it influences reproductive success and many aspects of the biology and ecology of a species
The family Thripidae has no sub-social species, but it contains most of the pest species that feed on plants, and several form male mating aggregations of tens to hundreds of males, which appear to be mediated by aggregation pheromones[5]

Summary

Introduction

Many species of thrips (Thysanoptera) in the family Thripidae form mating aggregations, but the adaptive significance of these aggregations and the extent of male and female mate choice is poorly understood. We studied the mating behaviour of the bean flower thrips Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), which forms male aggregations and occurs across sub-Saharan Africa. In the onion thrips T. tabaci Lindeman, male aggregations have not been reported, male-male fighting has been d escribed[18] For such species, it is possible that aggregation occurs, but has just not been observed in the field under the right conditions. One of the key features of a classical lek is that females have the opportunity to select m ales[19], but in thrips aggregations, there is male fighting in a few species, suggesting some kind of competition for females, there is no evidence of female choice. Evolutionary theory suggests that males should not be choosy, because the benefits of choosiness would not outweigh the costs of lost mating o pportunities[22,24] and that male mate choice is less likely to evolve when there is sequential c hoice[22]

Objectives

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Conclusion