Sex Pheromones and Reproductive Isolation in Five Mirid Species

Abstract

Mate location in many mirid bugs (Heteroptera: Miridae) is mediated by female-released sex pheromones. To elucidate the potential role of the pheromones in prezygotic reproductive isolation between sympatric species, we investigated differences in the pheromone systems of five mirid species, Apolygus lucorum, Apolygus spinolae, Orthops campestris, Stenotus rubrovittatus and Taylorilygus apicalis. GC/MS analyses of metathoracic scent gland extracts of virgin females showed that all five species produced mixtures of hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal, but in quite different ratios. (E)-2-hexenyl butyrate was the major component of A. spinolae, while hexyl butyrate was the most abundant component in the pheromone blends of the other four species. In addition to the three compounds, a fourth component, (E)-2-octenyl butyrate, was present in the gland extracts of A. lucorum and T. apicalis females. Field tests suggest that the ternary blends of hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal as found in the extracts of the females of each species do not inhibit attraction of conspecific males but ensure species-specificity of attraction between A. lucorum, O. campestris and T. apicalis. Furthermore, (E)-2-octenyl butyrate was essential for attraction of A. lucorum and T. apicalis males, but strongly inhibited attraction of male A. spinolae, O. campestris and S. rubrovittatus. The combined results from this study and previous studies suggest that the minor component and pheromone dose in addition to the relative ratio of the major components play an important role in reproductive isolation between mirid species.

Identification and field evaluation of the sex pheromone of Apolygus lucorum (Hemiptera: Miridae) in China

“…In many mirid species, virgin females have been shown to produce sex pheromones to attract males. 12 To date, the sex pheromones of more than 20 mirid species have been identified, including those of Campylomma verbasci, 13 Phytocoris spp., [14][15][16] Trigonotylus caelestialium, 17 Lygus spp., [18][19][20][21][22] Apolygus spp., 23,24 Adelphocoris spp., [25][26][27] Stenotus rubrovittatus, 28 Creontiades dilutus, 29 Sahlbergella singularis, 30 Distantiella theobroma, 31 Lygocoris pabulinus, 32 Liocoris tripustulatus, 22 Halticus minutus 33 and Bryocoropsis laticollis. 34 Components of these pheromones are typically saturated or unsaturated straight-chain esters or aldehydes.…”

“…Yang et al reported identification of the sex pheromone of the closely related Apolygus spinolae in South Korea, 23 and subsequently reported identification of the sex pheromones of five mirid species in South Korea, including both A. spinolae and A. lucorum. 24 Yang et al identified a four-component blend of hexyl butyrate, (E)-2-hexenyl butyrate, (E)-4-oxo-2-hexenal and (E)-2-octenyl butyrate, at a ratio of 10:2:2:2, as the sex pheromone of A. lucorum. 24 However, the four-component blend did not attract any plant bugs in fields planted with cotton and grape that suffered heavy losses from A. lucorum in northern China.…”

“…24 Yang et al identified a four-component blend of hexyl butyrate, (E)-2-hexenyl butyrate, (E)-4-oxo-2-hexenal and (E)-2-octenyl butyrate, at a ratio of 10:2:2:2, as the sex pheromone of A. lucorum. 24 However, the four-component blend did not attract any plant bugs in fields planted with cotton and grape that suffered heavy losses from A. lucorum in northern China.…”

Identification of a sex pheromone of the chrysanthemum lace bug Corythucha marmorata (Hemiptera: Tingidae)

“…In Miridae, closely related to the Tingidae, females of many species release long-range sex pheromones to attract conspecific males 10, 11 . To date, the sex pheromones produced by females of 16 species have been identified 12 .…”

Identification and laboratory behavioral test of the alarm pheromone of Acanthocoris sordidus Thunberg (Hemiptera: Coreidae)

“…Chemical signals could be applied to controlling pests through attract-kill and push-pull strategies (Roitberg 2007). In order to incorporate such chemical signals into pest management, identification of the chemicals and validation of their functions are necessary (Aldrich 1988;Noge et al 2012;Yang et al 2015;Zhang et al 2015).…”