A locust pheromone: Locustol

For some time a gregarizaiton pheromone has been postulated, and demonstrated, to account for the changes which take place in solitary locusts when they are crowded, i.e. for phase transformation. The airborne substance which is given off by locust faeces has been extracted and submitted to ultraviolet, infrared, mass, and nuclear magnetic resonance spectroscopy. The results indicated a derivative of guaiacol, which is a degradation product of the metabolism of the lignin of plants. This airborne substance is 2-methoxy-5-ethylphenol and has been synthesized and bioassayed on solitary phase locust hoppers. It proved positive in action on the quantitative phase traits such as increased chiasma frequencies during meiosis, melanization of hopper integument, changed adult morphometric ratios, and the behaviour of hoppers: this pheromone has been named locustol.