Bifunctional Pheromone in the First Instar of the Southern Green Stink Bug, Nezara viridula (L.) (Hemiptera: Pentatornidae): Its Characterization and Interaction with Other Stimuli

In first instar Nezara viridula (L.), olfactory and visual cues cause attraction, while visual and tactile cues are responsible for arrestment. A whole-body extract of 10 super(-2) individual equivalents was attractive; at higher concentrations of 10 super(0) and 10 super(1) individual equivalents, the extract was repellent and probably functioned in the dispersal of the aggregation. Using chemical, behavioral, and developmental data, n-tridecane was identified as a bifunctional pheromone of first instar N. viridula). The emerging nymphs do not possess this pheromone and do not reaggregate if separated; the initial nymphal aggregation is maintained by tactile stimuli. As the mymphs develop during the first 2 days, the amount of n-tridecane rises with a concommitant increase in the ability to reaggregate. From day 2 until molt to the second instar on day 5, the amount of pheromone and the index of aggregation does not change significantly.