Novel Cross-Stage Solitarising Effect of Gregarious-Phase Adult Desert Locust (Schistocerca Gregaria (Forska ˚l)) Pheromone on Hoppers
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Date
2010-01
Authors
Bashira, Magzoub O.
Hassanali, Ahmed
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Ltd
Abstract
Previous studies had demonstrated stage differentiation in the cohesion (aggregation) pheromone systems of the desert locust, Schistocerca gregaria. In laboratory arena, the nymphal and adult stages responded aggregatively to their own pheromone, but dispersed evenly within the arena in the presence of the other. In the present study, we explored the effects of longer-term contact of field gregarious hopper bands and laboratory crowd-reared nymphs with the major constituent of the adult pheromone. During the first few days, hoppers in treated bands became relatively hyperactive. Over the next few days, their movements became random and they stopped marching as coherent groups, they started to roost for longer periods on vegetations, and they fragmented into smaller and smaller groupings and individuals. When attacked by birds, they demonstrated subdued levels of collective defensive behaviour compared to normal hoppers, and there were clear signs of increased predation and cannibalism at the roosting sites. In cage experiments, crowd-reared nymphs treated with the pheromone component became hyperactive, showed abnormal diel patterns and reduced feeding on plants but increased cannibalism. Our observations show that the major adult pheromone constituent has asolitarising effecton gregarious hoppers. The mechanism underlying this effect and the potential of the agent in desert locust control are discussed.
Description
Article
Keywords
Desert locust, Schistocerca gregaria, Adult pheromone, Phenylacetonitrile, Nymphs, Solitarisation
Citation
Bashir, M. O., & Hassanali, A. (2010). Novel cross-stage solitarising effect of gregarious-phase adult desert locust (Schistocerca gregaria (Forskål)) pheromone on hoppers. Journal of insect physiology, 56(6), 640-645.