ARS | Publication request: Mass spectral determination of phenylacetonitrile (PAN) levels in body tissues of adult desert locust, Schistocerca gregaria

Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 22, 2012
Publication Date: July 15, 2012
Citation: Amwayi, P.W., Masiga, D.K., Govender, P., Teal, P.E., Torto, B. 2012. Mass spectral determination of phenylacetonitrile (PAN) levels in body tissues of adult desert locust, Schistocerca gregaria. Journal of Insect Physiology. 58:1037-1041.

Interpretive Summary: Plagues of Desert locusts have wreaked havoc in Africa since biblical times. The gregarious phase of the desert locust develops only under specific environmental conditions and the maintenance of locust swarms relies on production and release of a pheromone that causes the adults to aggregate. Until now very little has been known about where in the locust this pheromone is produced. Scientists from the International Centre of Insect Physiology and Ecology, Kenya, Departments of Zoology and Entomology, University of Pretoria, South Africa, Department of Biology, University of Limpopo, South Africa and Centre for Medical, Agricultural and Veterinary Entomology, USDA-ARS Gainesville, Florida have been studying where the aggregation pheromone is produced. They have discovered that the pheromone is 20-fold more concentrated in males than in females and that in females the pheromone is concentrated in the tarsal segments. The greatest amounts of pheromone were in 2- week old females and 3-week old male body parts, respectively. No trace of pheromone was found in similar ages and sexes of the solitarious phase desert locust. The wide distribution of pheromone in the bodies of both sexes of gregarious phase locusts suggests that no specific tissue is responsible for biosynthesis of the pheromone. Our results provide the first insights as to its distribution in the body matrix of both sexes and phases of the desert locust and that it is not limited to males.

Technical Abstract: : Wings and legs of the gregarious desert locust, Schistocerca gregaria have been shown to be release sites of phenylacetonitrile (PAN), the major adult male-produced pheromone. However, there is limited information on the distribution of PAN within the locust. Here we show, using gas chromatography-mass spectrometry (GC-MS), that PAN occurs in nearly all body parts of both adult males and females of the locust in varying amounts. PAN was 20-fold more concentrated in males than in females. In females, PAN was concentrated more in the tarsal segments. The greatest amounts of PAN were in 2- and 3-week old female and male body parts, respectively. No trace of PAN was found in similar ages and sexes of the solitarious phase desert locust. The wide distribution of PAN in the bodies of both sexes of gregarious phase locusts suggests that no specific tissue is responsible for biosynthesis of the pheromone. Our results support the role of PAN as a pheromone in sexually mature gregarious males, and they provide the first insights as to its distribution in the body matrix of both sexes and phases of the desert locust and that PAN is not limited to males.