Formate Analogs as Antagonists of the Sex Pheromone of the Honeydew Moth, Cryptoblabes gnidiella: Electrophysiological, Behavioral and Field Evidence

Abstract

Cryptoblabes gnidiella Milliére (Lepidoptera: Pyralidae) is an economically important exotic pest of vineyards in Southern Brazil and Uruguay. The sex pheromone of C. gnidiella was identified as a mixture of (Z)-11-hexadecenal and (Z)-13-octadecenal, and has been used to monitor populations of this pest in Israel. The development of mating disruption for this species may be hampered by the chemical instability of the natural pheromone components. Therefore, studies on more stable pheromone analogs may provide tools for a control strategy based on behavior-modifying chemicals. We report here the electrophysiological and behavioral responses of C. gnidiella males to (Z)-9-tetradecenyl formate and (Z)-11-hexadecenyl formate, structural analogs of the pheromone components. In gas chromatography-electroantennogram detection (GC-EAD) studies, both analogs elicited responses from C. gnidiella male antennae. Pre-exposure to the formates did not affect the subsequent EAD responses to the natural pheromone components. The formates acted as pheromone antagonists in wind tunnel tests, inhibiting the responses of males toward both synthetic pheromone and calling females. In the field, captures of males in pheromone-baited traps decreased, in a dose-response pattern, when different amount of formates were added to the pheromone. These pheromone antagonists, thus, are potentially useful as mating disruptants for C. gnidiella in commercial vineyards.

Odorant Receptors and Odorant-Binding Proteins as Insect Pest Control Targets: A Comparative Analysis

“…Besides the antagonist effect probed in vitro , the evidence at behavioral level supports the idea that structural analogs of pheromones can function as antagonists. For example, Sellanes et al ( 2010 ) reported the inhibition of sexual response in the honeydew moth Cryptoblabes gnidiella when the structural analogs, ( Z )-9-tetradecenyl formate and ( Z )-11-hexadecenyl formate, were added to synthetic sex pheromone, ( Z )-11-hexadecenal and ( Z )-13-octadecenal, in wind tunnel tests. This pheromone antagonist effect was later corroborated in field assays, where the trapping of C. gnidiella males decreased in a dose-dependent pattern.…”

Synthesis and Field Evaluation of the Sex Pheromone of Plutella xylostella (L.) (Lepidoptera: Plutellidae) in Canola (Brassica napus L.)

“…The (Z) isomer is here obtained with high stereoselectivity, with a (Z)/(E) ratio of 9/1. The final stage of the synthetic sequence is the oxidation of (Z)-11-hexadecenol to the pheromone component (Z)-11-hexadecenal (Sellanes et al, 2010) using pyridinium chlorochromate as oxidizing agent in 70 % yield. Acetylation of (Z)-11-hexadecenol with acetic anhydride in the presence of triethylamine and 4-dimethylaminopyridine afforded (Z)-11-hexadecenyl acetate in excellent yield (90 %) ( Figure 2).…”

Uso da técnica de confusão sexual no manejo populacional de Cryptoblabes gnidiella (Lepidoptera: Pyralidae) em videira

“…Assim, Sellanes et al (2010) estudaram as respostas eletrofisiológicas e comportamentais de machos de C. gnidiella às formas análogas de (Z)-11-hexadecenal e (Z)-13-octadecenal, dada a importância destes análogos estruturais mais estáveis, para aumentar a eficácia da técnica e potencializar seu uso no manejo de pragas.…”