Identification of a unique three‐component sex pheromone produced by the tea black tussock moth, Dasychira baibarana (Lepidoptera: Erebidae: Lymantriinae)

Abstract

BACKGROUND: The tea black tussock moth Dasychira baibarana Matsumura is a devastating pest in tea plantations that causes substantial economic losses. Presently, there is no effective method to control this pest other than pesticide application. The identified sex pheromone of D. baibarana could be used for detecting and monitoring this pest. RESULTS: Gas chromatography-electroantennogram detection showed that D. baibarana male moth antennae responded strongly to three components in the female sex pheromone gland, which were identified as: (3Z,6Z)-cis-9,10-epoxyhenicosa-3,6-diene (Z3,Z6,epo9-21:H) (I), (3Z,6Z,11E)-cis-9,10-epoxyhenicosa-3,6,11-triene (Z3,Z6,epo9,E11-21:H) (II) and (3Z,6Z)-henicosa-3,6-dien-11-one (Z3,Z6-21:11-one) (III). Dasychira baibarana uses a unique composition of an epoxydiene, epoxytriene, and dienone with the same 3,6-dienyl motif as its sex pheromone. The epoxytriene and dienone were not previously characterized as insect pheromone components. Electroantennogram analysis showed that each synthetic compound strongly stimulated male antennae, and compounds II and III elicited stronger responses than compound I. A wind tunnel bioassay and field trapping experiments proved that, ternary blends of compounds I-III attracted D. baibarana. Efficient attraction was achieved with a rubber septum baited with 500 ∼g of a mixture of compounds I-III at the ratio 25:20:55. CONCLUSION: The three identified compounds elicited an electroantennogram response in D. baibarana male moth antennae, and a mixture of the three components at the ratio 25:20:55 attracted D. baibarana male moths in a wind tunnel assay and field trapping experiments. This blend could be used for integrated management of D. baibarana in tea plantations.

Identification of sex pheromone in Macdunnoughia crassisigna Warren (Lepidoptera: Noctuidae) and field optimization of the sex attractant

“…This approach has previously yielded success in developing pheromone lures for various pest species. 14,16,[38][39][40] In this study, the pheromone ratio was established based on the reasonable quantities of Z7-12:OAc and Z9-14:OAc loaded into each septum. This approach has merit in terms of standardizing and commercializing insect attractants, because previous studies have confirmed the highly consistent proportion of moth pheromones released from rubber septa compared with the amount loaded.…”

“…We undertook a systematic sequence of steps, encompassing pheromone collection, antennal‐active component screening and identification, field‐level validation and optimization, and monitoring assays involving pheromone lures. This approach has previously yielded success in developing pheromone lures for various pest species 14,16,38–40 . In this study, the pheromone ratio was established based on the reasonable quantities of Z7‐12:OAc and Z9‐14:OAc loaded into each septum.…”

Aggregation pheromones released by nymphs of the stick tea thrips (Dendrothrips minowai): identification and analysis of their potential utility for controlling thrips in tea plantations

“…An air stimulus controller (CS-55; Syntech) was used to generate air ow (300 mL/min for 0.5 s) that passed the odor cartridge before entering the main air stream. Both dodecyl acetate and tetradecyl acetate were dissolved in para n oil and then serially diluted (0.001, 0.01, 0.1, 1, and 10 µg/µL), after which a 10 µL aliquot was added to a lter paper strip (0.5 cm × 5 cm) that was placed inside a glass Pasteur pipette (Magsi et al, 2022). The odorants were used for the subsequent EAG assay, with para n oil serving as the blank control.…”

“…Pheromones are chemicals secreted by insects to induce physiological or behavioral changes of the same or different species, which made them important semiochemicals for intraspeci c and interspeci c communication (Yan et al, 2013;Czaczkes et al, 2015;Seybold et al, 2018). The identi ed insect pheromones include sex pheromones, aggregation pheromones, trail pheromones, alarm pheromones, marking pheromones, and other types (Witzgallet al, 2010; Morrison et al, 2017;Magsi et al, 2022).…”

Identification of aggregation pheromones released by the stick tea thrips (Dendrothrips minowai) larvae and their application for controlling thrips in tea plantations

“…Pheromones are chemicals secreted by insects to induce physiological or behavioral changes in intraspecific members and therefore play a crucial role in intraspecific communications 8,12,13 . Insect pheromones encompass various types, including sex pheromones, aggregation pheromones, alarm pheromones and trail pheromones, among others 14 . Aggregation pheromones, emitted by both male and female insects and during immature stages (such as eggs, nymphs/larvae, and pupae), function as attractants for both sexes 17 .…”