Greenbug Response to an Alarm Pheromone Analog: Temperature and Humidity Effects, Disruptive Potential, and Analog Releaser Efficacy

Greenbug, Schizaphis graminum (Rondani), response to the nor-farnesene aphid alarm pheromone analog (E)-2,6,10-trimethylundeca-1,5,9-triene was suppressed by high (35°C) and low (4°C) temperatures, with maximal reaction occuring at ca. 29°C. Response of aphids to pheromone increased with increasing humidity from 15-75% RH, but dropped precipitously at 95% RH. The disruptive potential of the alarm pheromone analog also is limited by the nonresponsive behavior of some individuals, and especially by exposure to sub-threshold levels. Polyethylene vial dispensers produced the highest level of greenbug response to the alarm pheromone, but the effect was short-lived. Zeolites provided a longer and lower, but relatively constant rate of aphid response.