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

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.

Reproductive Isolation in the Cryptic Species Complex of a Key Pest: Analysis of Mating and Rejection Behaviour of Onion Thrips (Thrips tabaci Lindeman)

“…We were not able to detect any specific behaviour before interaction events that could have had a connection with successful mating, such as increased activity or vibration of wings, as was found by Milne et al [45] with F. schultzei. However, the precopulation and mating behaviour of T. tabaci generally followed the same sequences as of other reported thripid species [41,[43][44][45][46][47].…”

“…Thelytoky (obligate parthenogenesis) in Thysanoptera is automictic, and the ploidy restoration results in only female progeny [37,38]. In nature, some thripid species are known to form male aggregations, where they also mate with the landing females [39][40][41]. The formation of these aggregations is probably mediated by male-produced aggregation pheromones [42].…”

“…A detailed description, with some additional notes on other species, of the mating behaviour is available for only five species: Frankliniella occidentalis (Pergande) [43,44], Frankliniella schultzei Trybom [45], Scirtothrips aurantii (Faure) [46], Echinothrips americanus Morgan [47] and Megalurothrips sjostedti (Trybom) [41]. However, in the case of cryptic complexes, these descriptions might not be perfectly correct for all the species or lineages.…”

“…Species in the family Thripidae seem to differ in the number of matings during their lifetimes. Males are able to inseminate many females [43,47], but they can also be choosy and avoid mating [41]. In some species, females only mate once-or at least refuse to mate for an extended period of time after one successful mating-which is probably the result of a male-produced anti-aphrodisiac pheromone applied on the back of the females during mating [44,48,49].…”

“…In some species, females only mate once-or at least refuse to mate for an extended period of time after one successful mating-which is probably the result of a male-produced anti-aphrodisiac pheromone applied on the back of the females during mating [44,48,49]. In some other species, however, females mate multiple times [41,50].…”