MONOTERPENE EMISSIONS AND CUTICULAR LIPIDS OF LOBLOLLY AND SLASH PINES - POTENTIAL BASES FOR OVIPOSITION PREFERENCE OF THE NANTUCKET PINE TIP MOTH

Monoterpene emissions from intact 5- to 29-month-old loblolly and slas h pine seedlings contained alpha-pinene, camphene, beta-pinene, myrcen e, sabinene, beta-phellandrene, and limonene. alpha-Pinene made up >50 % of the volatiles from both species. beta-Pinene was significantly mo re abundant in slash (35.6%) than in loblolly pine (15.3%), while myrc ene was significantly more abundant in loblolly (10.9%) than in slash pine (3.4%). Cuticular lipids represented 0.11 and 0.06% of the dry we ight biomass of shoots from loblolly and slash pines, respectively. Sp ecies differences in cuticular lipid composition were primarily in rel ative proportions of a group of unidentified compounds that appear to be saturated and unsaturated diols and (or) hydroxy alcohols with chai n lengths of about 18 carbons. 10-Nonacosanol made up 16.2 and 14.1% o f the total lipids recovered from loblolly and slash pines, respective ly. The Nantucket pine tip moth, Rhyacionia frustrana (Comstock), may use these chemical differences to distinguish the susceptible loblolly pines from the resistant slash pines.