Communication interference in sympatrically occurring moth species

JUÁREZ M.L.; RUIZ, M. J.; FERNÁNDEZ, P.; GOANE, L.; VILLAGRÁN, M. E.; ARCE, O.; ARMIÑANA, A.; PÁEZ JEREZ, P.; DE LA VEGA, M. H.; VERA, M.T.; GROOT, A.T.

Congreso; IX Congreso Argentino de Entomología 2015; 2015

In moth species, the recognition and attraction between sexes involves distinctive female-emitted sex pheromones that are perceived over long distance by conspecific males. The specificity in the chemical communication channel ensures the co-occurrence of different species in the same habitat. However, communication interference is likely to occur between closely related species that share pheromone compounds. In areas of sympatry this may induce reproductive character displacement, leading to a divergence of the signals based on the presence of unique components, unique ratios of components, or by interspecific antagonists (pheromone components that cause inhibition of male upwind flight). Given the evolutionary significance and the possible practical application of using antagonistic behaviour resulting in communication interference as a pest management tool, we aimed to compare the response of Helicoverpa gelotopoeon males in the presence of the major sex pheromone component of sympatrically occurring heliothine moths, Z11-16:Ald, as well as the critical secondary pheromone component of the sympatrically occurring Heliothis virescens, Z9-14:Ald. We also explored whether other species from the same habitat were attracted to these compounds. Field experiments were conducted with traps baited with a synthetic blend that mimics the pheromone of H. gelotopoeon and different ratios of Z11-16:Ald alone or in combination with Z9-14:Ald. We showed that the addition of Z11-16:Ald alone or in combination with Z9-14:Ald inhibited the catches of H. gelotopoeon males, depending on the concentration of these compounds. In addition, other species of noctuid moths were attracted to the blends, specifically Neotuerta platensis, H. virescens and species belonging to defoliating moths complex as Anticarsia gemmatalis, Chrysodeixis includens and Rachiplusia nu. Together, our results confirm the antagonistic effect of heterospecific sex pheromone compounds of H. virescens in H. gelotopoeon.