Phytoparasitica (2000) 28, 7-26

Peter Trumm and August Dorn (2000)
Effects of azadirachtin on the regulation of midgut peristalsis by the stomatogastric nervous system in Locusta migratoria
Phytoparasitica 28 (1), 7-26
Abstract: A single injection of azadirachtin into nymphal and adult locusts results in a decrease of food intake but not in reduced food utilization. Feeding deterrency is correlated with a gradual inhibition of midgut peristalsis. Gut movement is under the control of the stomatogastric nervous system, especially the ingluvial ganglion, as demonstrated in an in vitro system. Serotonin is the most potent peristalsis-stimulating drug in vitro. Concurrent with the cessation of midgut peristalsis after azadirachtin injection, a depletion of the serotoninergic cell bodies in the frontal ganglion can be observed. Midgut preparations which show strongly inhibited contractions due to previous azadirachtin treatment in vivo are minimally, or not at all, stimulated in vitro by serotonin, depending on the amount of time that has elapsed since treatment. When midgut preparations of untreated locusts are challenged with azadirachtin in vitro, peristalsis is suppressed in a dose-dependent manner. Simultaneous application of azadirachtin and serotonin results in a slight stimulation of midgut peristalsis. We propose the hypothesis that azadirachtin interferes with the serotoninergic system of the stomatogastric ganglia and thus inhibits midgut peristalsis. The molecular mechanism of the action of azadirachtin remains to be determined.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): August Dorn

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Locusta migratoria