GUSTATORY REJECTION THRESHOLDS FOR THE LARVAE OF THE CECROPIA MOTH, SAMIA CECROPIA (LINN.)

Abstract

Thresholds were detd. for HCl, CH3COOH, NaOH, NaCl, NH4C1, KCl, CaCl2, and LiCl in drops of solns. on leaves of the food plant. Glucose, sucrose, lactose, and strychnine sulfate were not rejected under these conditions. HCl was rejected at the lowest cone, studied, but CH3COOH was more stimulating than HCl at the same pH. The threshold for NaOH is higher than that for HCl, indicating that the OH" ion is less stimulating than the H3O+ ion. The order of stimulative efficiency for the cations, as chlorides, is NH4+ = K+ > Ca++ > Na+ > Li+. This is the order of ionic mobilities to which the stimulative efficiencies seem to be related.