Support for (Z)-11-Hexadecanal as a Pheromone Antagonist in Ostrinia nubilalis: Flight Tunnel and Single Sensillum Studies with a New York Population

Abstract

The flight-tunnel response of male Z-strain European corn borer moths (ECB), Ostrinia nubilalis, from a population in New York State (USA), was significantly antagonized by addition of 1% (Z)-11-hexadecanal (Z11-16:Ald) to their sex pheromone (a 97:3 mix of (Z)- and (E)-11-tetradecenyl acetate [Z/E11-14:OAc]). The level of antagonism was equivalent to that observed for the previously identified ECB antagonist, (Z)-9-tetradecenyl acetate (Z9-14:OAc), and supports a recent report showing that Z11-16:Ald, a minor pheromone component of the Noctuid moth, Sesamia nonagrioides, caused antagonism of ECB pheromone communication in sympatric populations in the Iberian Peninsula. Single-sensillum recordings from ECB antennae, which included cross-adaptation experiments, showed that the same olfactory receptor neuron processing Z9-14:OAc inputs was responsible for detecting Z11-16:Ald, and that this neuron was not responsive to two other aldehydes, (Z)-9-tetradecanal (Z9-14:Ald) and (Z)-9-hexadecanal (Z9-16:Ald), found in other moth sex pheromones. Our results show that the antagonism is not confined to one geographic region, is specific for Z11-16:Ald, and that antagonist pathways might have the potential for processing a number of structurally similar compounds.

Sex Pheromone Receptor Specificity in the European Corn Borer Moth, Ostrinia nubilalis

“…‘Rare’ ECB and ACB males, typically representing 3–5% of the population, are less specific in their behavioral response to related pheromone blends [6]. Changes in the periphery that alter the strength or specificity of the olfactory neuron's response to specific pheromone components could account for the rare responses [22]–[24].…”

“…For ECB(E) males, a large-spiking neuron responds to the main pheromone component, a small-spiking neuron responds to the minor component, and an intermediate-spiking neuron responds to Z9-tetradecenyl acetate (Z9-14:OAc) [20]–[24]. The olfactory pathway responding to Z9-14:OAc antagonizes responses to the attractive pheromone pathway and prevents upwind flight to similar sex pheromone blends that include Z9-14:OAc [6].…”

Thematic Review Series: Sphingolipids. Biodiversity of sphingoid bases (“sphingosines”) and related amino alcohols

“…Fatty aldehydes are also highly reactive compounds and have been associated with the pathogenesis of Sjögren-Larsson syndrome, an inherited neurocutaneous disorder caused by mutations in the enzyme that catalyzes the oxidation of fatty aldehydes to fatty acids (191). Fatty aldehydes are also encountered as natural components of food (and food additives) (192) and as insect pheromones (193, 194). …”

Journey in the Ostrinia World: From Pest to Model in Chemical Ecology

“…Other compounds have been reported for their antagonism of ECB pheromone, with the addition of as little as 1% in the pheromone blend leading to antagonism: (E)-9-tetradecenyl acetate (E9-14:OAc), (E)-and (Z)-9-dodecenyl acetate (E9-12:OAc and Z9-12:OAc, respectively) (Klun and Robinson, 1972;Struble et al, 1987;Glover et al, 1989), as well as (Z)-11-hexadecenal (Z11-16: Ald) (Gemeno et al, 2006;Linn et al, 2007a). These compounds have not been found as part of the pheromone blend of any Ostrinia species (Ishikawa et al, 1999b).…”