The male‐produced aggregation pheromone of the bean flower thrips Megalurothrips usitatus in China: identification and attraction of conspecifics in the laboratory and field

Abstract

BACKGROUNDThrips, Megalurothrips usitatus, usually display aggregation behavior, which is probably mediated by a male‐produced aggregation pheromone. Aggregation pheromones are species‐specific, and can be used to develop commercial lures for monitoring and mass‐trapping of pests. The active components of the aggregation pheromone for four thrips species have been identified. However, the components of M. usitatus‐produced aggregation pheromone are still not clear.RESULTY‐tube olfactometer assays showed that both male and virgin female M. usitatus were significantly attracted to male but not female volatiles. This was additionally supported by electroantennogram (EAG) assays. Coupled gas chromatography‐electroantennogram detection (GC‐EAD) showed that one component of male‐specific odors elicited a significant electrophysiological response. This compound was characterized as (2E,6E)‐farnesyl acetate, which is structurally different from the active components of the aggregation pheromones of other reported thrips species. Electroantennal responses of M. usitatus increased with increasing doses of synthetic (2E,6E)‐farnesyl acetate. Additionally, this compound significantly attracted adults in laboratory behavioral bioassays. Under field conditions, sticky traps with synthetic (2E,6E)‐farnesyl acetate caught 1.5‐7‐fold more M. usitatus than controls, and this effect of the compound at a dose of 60 μg lasted at least 6 days.CONCLUSION(2E,6E)‐Farnesyl acetate was identified as the male‐produced aggregation pheromone of M. usitatus. It could attract this thrips species under laboratory and field conditions, suggesting considerable potential as a commercial application to control M. usitatus populations. © 2020 Society of Chemical Industry

Exploiting Thrips Aggregation Pheromones to Develop a Lure-and-Kill Strategy for the Management of the Bean Flower Thrips

“…The chemical nature of an insect semiochemical is also likely to impact its compatibility with biopesticides [18,20,36]. The active ingredient of Lurem-TR, methyl-isonicotinate, is an ester of a 4-pyridyl-carboxylic acid [39], while the M. sjostedti and F. occidentalis aggregation pheromones are terpenoids [14,23,[40][41][42]. Similarity in the chemistry of M. sjostedti and F. occidentalis pheromones may account for their similar antifungal effects on M. anisopliae and their difference from Lurem-TR.…”

Problems with the Concept of “Pest” among the Diversity of Pestiferous Thrips

“…The three major genera that comprise this group all involve species that breed mainly in the flowers of Fabaceae. Species in two of them, Odontothrips and the Australian genus Odontothripiella, are rarely associated with crop plants, whereas several species of Megalurothrips are important as pests of bean crops in tropical and subtropical countries [57][58][59]. Two further genera that are possibly related to this genus-group are Ceratothripoides and Pezothrips [37].…”

Bean Flower Thrips Megalurothrips usitatus (Bagnall) (Insecta: Thysanoptera: Thripidae)

“…Adult Megalurothrips usitaus are mostly active between 8:00-10:00 am while being inactive at night. Megalurothrips usitatus exhibit aggregation behavior which is thought to be due to the male-produced aggregation pheromone (Liu et al 2020). Megalurothrips usitatus male and females are found aggregated on the host and their numbers increased after the mid-blooming stage.…”

“…Blue sticky traps are the most attractive to Megalurothrips usitatus (Yan et al 2017). The male produced aggregation pheromone of Megalurothrips usitatus can be used to develop commercial lures to monitor the pest and mass trapping (Liu et al 2020).…”