Abstract
The functional characteristics of gustatory receptors on the maxillary sensilla styloconica (Ss-I, Ss-II) were investigated in the common cutworm larvae, Spodoptera litura Fabricius. It was shown that four gustatory receptors are present on Ss-I: a salt receptor (N1), a sugar receptor (S1), a “bitter substance” receptor (R), and a water receptor (W). Two salt receptors (N2, N2'), a fructose receptor (S2) and an inositol receptor (I) were found on Ss-II. The receptive threshold of each receptor to the gustatory substance was measured. The threshold values of the S1-receptor to sucrose, the S2-receptor to fructose, the I-receptor to inositol and the R-receptor to sinigrin were 10-4M, 10-2M, 10-4M, and 10-3M, respectively. Sugars activated the S1-receptor as a feeding stimulant and inhibited the sensitivity of the R-receptor.
