Electroantennogram, wind tunnel and field responses of male Mediterranean corn borer, Sesamia nonagrioides, to several blends of its sex pheromone components

Abstract

The electrophysiological and behavioural responses of male Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae) to several synthetic blends of its sex pheromone components were investigated. Electroantennogram (EAG) recordings showed the greatest response to a 77:8:10:5 blend of the four compounds found in the female glands: (Z)‐11‐hexadecen‐1‐yl acetate, (Z)‐11‐hexadecen‐1‐ol, (Z)‐11‐hexadecenal and dodecyl acetate. A logistic equation was fitted to the dose‐response data and differences in relative EAG responses were analysed by deriving five parameters of this equation. Flight responses of males were also evaluated in a wind tunnel where the proposed blend (77:8:10:5) also elicited the best response. Field tests confirmed the laboratory findings as the 77:8:10:5 blend captured more S. nonagrioides males than other pheromone mixtures and showed more selectivity for male S. nonagrioides over other noctuid species, Discestra trifolii Rottenberg and Lacanobia oleracea L., but not for Mythimna unipuncta Haworth, a species with a sex pheromone composition almost identical to that of S. nonagrioides.

Response of Mythimna unipuncta Males to Components of the Sesamia nonagrioides Pheromone

“…The pheromone blend identified by Sans et al (1997) was the most attractive to S. nonagrioides males. Captures were low with (Z)-11-hexadecenyl acetate alone and while the addition of (Z)-11-hexadecenal did significantly increase the number of males captured, the addition of either (Z)-11-hexadecen-1-ol, (Z)-9-hexadecenyl acetate, or dodecyl acetate did not (Fig.…”

“…4). The addition of (Z)-11-hexadecenal, a minor component found in S. nonagrioides female pheromone glands and that is an essential component of the most effective S. nonagrioides lure (Sans et al 1997), resulted in year. All lures except WL contained (Z)-11-hexadecenyl acetate, the major pheromone component of Mythimna unipuncta and Sesamia nonagrioides.…”

“…Z9 indicates the addition of 1 µg of (Z)-9-hexadecenyl acetate. SePh is the complete pheromone of S. nonagriodes (Sans et al 1997), and WL indicates empty traps. Catches in traps where the lures contained (Z)-11-hexadecenal are marked with an asterisk.…”

“…Different letters on the top of bars indicate significant differences in the number of males captured Pp represents 100 µg of (Z)-11-hexadecenyl acetate, while Pp + OH, Ald or 12 indicate the addition of (Z)-11-hexadecen-1-ol, (Z)-11-hexadecenal, or dodecyl acetate (5 µg), respectively. Z9 indicates the addition of 1 µg of (Z)-9-hexadecenyl acetate, SePh is the complete pheromone of S. nonagriodes (Sans et al 1997), and WL indicates empty traps. Catches in traps where the lures contained (Z)-11-hexadecenal are marked with an asterisk.…”

Asymmetric synthesis of long chain α-methyl-β-thiotrifluoromethyl ketones employing the SAMP-/RAMP-hydrazone alkylation methodology

“…27,28 Introduction of a methyl group in alpha position to the carbonyl of OTFP has shown a further increase of the inhibitory potency in comparison to the non-substituted compound. 16 Following this trend, we herein report the racemic and asymmetric synthesis of a-methyl-b-thiotrifluoromethyl ketones (R)-1a, (R)-1b, (S)-1a, and (S)-1b, pheromone inhibitors of two major pests of maize, the Mediterranean corn borer Sesamia nonagrioides 29,30 and the European corn borer Ostrinia nubilalis, 31,32 as new potential biorational pest control agents. The racemic compounds can be obtained in a straightforward manner by condensation of the corresponding thiol and 3-bromo-1,1,1-trifluoro-2-butanone.…”