Intraindividual variations of volatile terpene contents in Pinus caribaea needles and its possible relationship to Atta laevigata herbivory

Abstract

Volatile terpene content variations in Pinus caribaea needles are examined in relation to season, dry hour, and canopy level. According to the results, the concentration of s-pinene was lower and that of sabinene and caryophyllene higher in the dry season than in the rainy season. s-Pinene, camphene, and s-phellandrene were more abundant in needles located at the lower canopy level, and limonene, α-ocimene, and the mixture of myrcene+α-phellandrene were more abundant at the upper canopy level. Camphene, sabinene, myrcene+α-phellandrene, and s-cadinene+γ-cadinene were more abundant in the afternoon, with lower concentrations at night. These results indicate that intraindividual variations in the contents of volatile terpenes in Pinus caribaea needles are significant even in regard to interindividual differences. The foraging pattern of the leafcutting ant Atta laevigata, as observed in a Caribbean pine plantation, could be, in part, related to these intraindividual variations.