Effect of β-cyano-l-alanine on the water balance of Locusta migratoria

Administration of β-cyano-l-alanine (BCNA) to adult locusts results in a significant decrease in haemolymph volume within one day. Dehydration becomes acute within 2 to 3 days and causes death within 5 days. This syndrome is attributed to impaired ability of BCNA-treated locusts to reabsorb water into the haemolymph from the rectal lumen. Extracts of brains and last abdominal ganglia, or haemolymph of water deprived locusts have no effect on rectal water resorption in BCNA-treated locusts. The initial symptoms of BCNA toxicity can be temporarily alleviated by injection of water into the haemocoel. Chronic BCNA toxicity irreversibly disrupts the control of water balance in locusts.