Rehovot 76100, Israel Locusts are in essence polymorphic grasshoppers, whose morphology and behavior are affected by population density. Isolated solitarious individuals tend to avoid contact and are more subdued. They march in bands as nymphs and swarm as adults.
Locusts communicate chemically in the process of phase transition.
Nothing is known about the events that follow initial signal transduction on exposure of solitarious nymphs to the cuticular lipid extract. We have observed several responses further downstream as a consequence of high population density or exposure to cuticular lipids. High population density induces increases in haemolymph metabolites. Exposure of solitarious nymphs to the cuticular lipids rapidly adjusts the levels of these specific peptides to those representative of gregarious nymphs. Injection of brain or CC extracts elicits gregarious behaviour.