Sex pheromone components of the turnip moth,Agrotis segetum

Abstract

Analysis of female abdominal tips ofAgrotis segetum by means of GC-MS showed the presence of 13 aliphatic acetates and alcohols. (Z)-7-Dodecenyl acetate was found to be the main component in the extracts at amounts of about 1 ng/female. (Z)-9-Tetradecenyl acetate and (Z)-7-dodecenol were present to the extent of 49 and 19%, respectively, of the main component. Minor components could be identified as decyl acetate, (Z)-5-decenyl acetate, dodecyl acetate, (Z)-9-dodecenyl acetate, tetradecyl acetate, a tetradecenyl acetate, hexadecyl acetate, a hexadecenyl acetate, (Z)-5-decenol, and (Z)-9-tetradecenol. The presence and biological activity of decyl acetate, (Z)-5-decenyl acetate, and (Z)-7-dodecenyl acetate in the extracts could be detected by GC-EAD. Tested by EAG (Z)-5-decenyl acetate evoked the highest response among pheromone candidates, followed by (E)-5-decenyl acetate and (Z)-7-dodecenyl acetate. Single-cell recordings from 100 male antennal sensilla trichodea revealed receptorcells highly sensitive to (Z)-5-decenyl, (Z)-7-dodecenyl, (Z)-8-dodecenyl, and (Z)-9-tetradecenyl acetate as well as (Z)-5-decenol. The (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetate receptors were activated significantly also by female extracts. When tested in a tube olfactometer, a blend of decyl, (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetate evoked the same male response as did female glands.Tested in the field, this blend was more attractive than virgin females. Other authors previously reported many of the compounds identified in the present study. However, both quantitative and qualitative discrepancies exist among the various investigations, possibly due to the existence of geographical races.

Functional Evolution of a Multigene Family: Orthologous and Paralogous Pheromone Receptor Genes in the Turnip Moth, Agrotis segetum

“…Except for the four pheromone components and two behavioural antagonists, we also included decyl acetate (10:OAc) as a stimulus for the oocytes, a component in the female sex pheromone gland extract that could elicit electroantennogram (EAG) activity, and early on was considered to be essential for full behavioural activity in the laboratory behavioural bioassay [11]. Thus seven chemicals were applied to the injected oocytes successively.…”

“…A. segetum makes use of a sex pheromone consisting of four structurally similar sex pheromone components ( Z )-5-decenyl, ( Z )-5-dodecenyl, ( Z )-7-dodecenyl and ( Z )-9-tetradecenyl acetates ( Z 5-10:OAc, Z 5-12:OAc, Z 7-12:OAc, and Z 9-14:OAc), that are specifically perceived by distinct types of sensilla trichodea in males. A detailed single-sensillum recording study demonstrated that for Z 5-10:OAc-type sensilla (Type-1 sensilla) there are at least three subtypes, each possessing a different tuning profile to other components [11-13]. The projection of olfactory receptor neurons (ORNs) to different regions of the macroglomerular complex is also quite specific [14] but potential differences in the projection of ORN subtypes were not investigated.…”

Discrimination among pheromone component blends by interneurons in male antennal lobes of two populations of the turnip moth, Agrotis segetum.

“…15 Swedish than to the Zimbabwean blend could be ascribed to the dose effect, since the amount of components in the Swedish blend is higher than that in the Zimbabwean blend. However, we also found neurons that responded preferentially to the Zimbabwean blend, i.e., a higher response to a lower dose, a phenomenon that has to be interpreted as a true blend effect.…”

Endogenous control of circadian rhythms of pheromone production in the turnip moth, Agrotis segetum

“…Previous study has shown that there is very little pheromone production of the turnip moth during the photophase (Löfstedt, 1984). One day after emergence, females were put under DD and pheromone production were examined for 3 consecutive days at the same time as when females were kept in LD cycle.…”