Pheromone trapping for the green mirid, 'Creontiades dilutus'

Abstract

With the reduction in the use of broad-spectrum insecticides, sucking bugs are becoming significant pests in transgenic cotton. One of these pests is the green mirid, 'Creontiades dilutus' (Stål) (Hemiptera: Miridae), which damages the terminals and fruiting bodies of cotton. The sex pheromone of 'C. dilutus' has been identified as a two-component blend in a 5:1 ratio of hexyl hexanoate and a female-specific compound, (E)-2-hexenyl hexanoate, respectively. We conducted pheromone trapping trials on cotton at various locations in NSW and Queensland to evaluate the potential of using pheromones as monitoring tools for 'C. dilutus'. Sampling for mirids was also done in these sites to establish any correlation between trap catches and mirid numbers in the field. Mirid samples were dissected to determine the sex ratio and mated status of females. Our data showed that the population dynamics of mirids were different between locations. Pheromone catches were significantly correlated with field mirids at some sites, whilst such correlation was not observed at other sites. Furthermore, in some cases, pheromone traps appeared to catch male mirids only when female mirids in the field were mostly mated, suggesting that the effectiveness of pheromone traps might be influenced by the "female competition" effect in the field.