Identification of kairomones of second instar nymphs of the variegated coffee bug Antestiopsis thunbergii (Heteroptera: Pentatomidae)

Njihia Teresiah, Torto Baldwin, Murungi Lucy Kananu, Irungu Janet, Mwenda Dickson, Babin Régis. 2017. Identification of kairomones of second instar nymphs of the variegated coffee bug Antestiopsis thunbergii (Heteroptera: Pentatomidae). Chemoecology, 27 (6) : 239-248.

Quartile : Q3, Sujet : ECOLOGY / Quartile : Q4, Sujet : BIOCHEMISTRY & MOLECULAR BIOLOGY

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Psychologie-éthologie-ergonomie

Résumé : The variegated coffee bug Antestiopsis thunbergii Gmelin is a key pest of Coffea arabica in East Africa. Although the bug feeds on various parts of the coffee plant, it has a strong preference for mature green berries which are essential for the bug to complete its life cycle, reproduce and enhance its longevity. To locate mature green coffee berries, we hypothesized that second instar nymphs, which are the most mobile and active feeding immature stage of the bug, must rely on key volatile compounds emitted by the host for recognition. We tested this hypothesis using behavioral and electrophysiological assays and chemical analysis. In olfactometer assays, the second instar nymphs were strongly attracted to volatiles emitted from mature green berries but avoided those from ripe coffee berries of C. arabica. Coupled gas chromatography–electroantennographic detection (GC/EAD) isolated five antenally active components from mature green berries volatiles, four of which were identified by coupled GC–mass spectrometry as toluene, anisole, methyl 3-ethyl-4-methylpentanoate and (5S,7S)-conophthorin. In concentration assays, in which second instar nymphs did not respond to toluene, they were strongly attracted to anisole, methyl 3-ethyl-4-methylpentanoate and (5S,7S)-conophthorin, and a blend from the three compounds at concentrations lower or equivalent to the natural volatile extract. Our results suggest that the blend from these three compounds allows host recognition in second instar nymphs of the variegated coffee bug and is a candidate kairomone for monitoring the pest in coffee plantations.

Mots-clés Agrovoc : Coffea arabica, kairomones, Pentatomidae, relation hôte parasite, composé volatil, composé de la flaveur, attractif, maturité, chromatographie en phase gazeuse, spectrométrie de masse

Mots-clés géographiques Agrovoc : Kenya

Mots-clés complémentaires : Antestiopsis orbitalis

Mots-clés libres : Antestiopsis orbitalis, Antestia bug, Coffea arabica, Kairomones

Classification Agris : H10 - Ravageurs des plantes
U30 - Méthodes de recherche

Champ stratégique Cirad : Axe 4 (2014-2018) - Santé des animaux et des plantes

Auteurs et affiliations

• Njihia Teresiah, ICIPE (KEN)
• Torto Baldwin, ICIPE (KEN)
• Murungi Lucy Kananu, Jomo Kenyatta University of Agriculture and Technology (KEN)
• Irungu Janet, ICIPE (KEN)
• Mwenda Dickson, ICIPE (KEN)
• Babin Régis, CIRAD-BIOS-UPR Bioagresseurs (KEN) ORCID: 0000-0002-3753-1193

Source : Cirad-Agritrop (https://agritrop.cirad.fr/585934/)

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