Journal of Chemical Ecology (1997) 23, 1373-1388

Yousif O.H. Assad, Ahmed Hassanali, Baldwyn Torto, Hassane Mahamat, Nabil H.H. Bashir and Sayed El Bashir (1997)
Effects of fifth-instar volatiles on sexual maturation of adult desert locust Schistocerca gregaria
Journal of Chemical Ecology 23 (5), 1373-1388
Abstract: The effect of the presence of gregarious fifth-instar nymphs on the sexual maturation of newly molted gregarious immature adult males and females of the desert locust S. gregaria was investigated by monitoring color changes (yellowing of body), sexual activity, aggregation-maturation pheromone titers (as measured by phenylacetonitrile levels in males), oocyte length, and oviposition time. Maturation was significantly delayed in adults that were reared together with fifth-instar nymphs (visual, tactile, and chemical signals present) with respect to all parameters measured. Male and female nymphs were equally effective in inducing this delay. Nymphs kept in an upper compartment of two-chamber cages (no visual or tactile contact possible) were similarly effective, but their feces were ineffective, suggesting the mediation of a volatile signal from the nymphs themselves. This was confirmed by examining the effect of volatiles trapped from nymphs and testing synthetic blends of previously identified nymphal aggregation pheromone components (C₆, C₈-C₁₀ aliphatic aldehydes and acids, guaiacol, and phenol) on the sexual maturation of adults. These and previous studies suggest a dual role for nymphal volatiles as nymphal aggregants and adult maturation retardants, similar to the adult volatiles that are known as adult aggregants and maturation accelerants. The results are discussed in terms of the role of the two pheromone systems in synchronizing maturation of the gregarious adults.
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Link to article at publishers website
Database assignments for author(s): Baldwyn Torto, Ahmed Hassanali

Research topic(s) for pests/diseases/weeds:
pheromones/attractants/traps
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Schistocerca gregaria