image: This is a flow diagram summarizing the major findings of the paper. When solitarious locusts are crowded they receive two sets of stimuli which signify the presence of other locusts. The hind legs receive mechanosensory stimuli from jostling locusts, and the head receives smell and sight stimuli signifying the presence of other locusts. This leads to an increase in serotonin in the nervous system which initiates the change in behavior from solitary (repelled by other locusts) to gregarious (attracted to other locusts). Drugs that prevent serotonin interacting with its receptors, or prevent serotonin being made, stop locusts changing in behavior. Conversely, injecting serotonin or drugs that mimic its effect cause locusts to behave gregariously, even when they haven't received gregarizing stimuli from other locusts. This image accompanied the report "Serotonin Mediates Behavioral Gregarization Underlying Swarm Formation in Desert Locusts," by Dr. Anstey and colleagues appearing in the Jan. 30, 2009, issue of Science. view more
Credit: Image copyright Steve Rogers via <i>Science</i>-AAAS.