Abstract
We found that Pieris rapae larvae secreted oily droplets from the dorsal setae. By using GC-MS analysis, we identified palmitic acid and stearic acid as the major components in the secretion. We already reported that Cotesia glomerata, a parasitoid of P. rapae larvae, showed characteristic antennation to palmitic acid and stearic acid in the host-infested edge of the leaf. Based on our previous reports together with the result of this study, we inferred that the two fatty acids in the droplets were used by C. glomerata in her host searching.
