C-7-2

SYNTHESIS AND TRANSPORT THROUGH THE HEMOLYMPH OF AHYDROCARBON PHEROMONE IN A TIGER MOTH (LEPIDOPTERA: ARCTIIDAE).

Coby Schal, Veeresh L. Sevala and Ring T. Cardé¹
Dept. Entomology, Box 7613, North Carolina State Univ., Raleigh, NC27695-7613
¹Dept. Entomology 041, Univ. of California, Riverside, CA92521

Long-chain hydrocarbons (HC) form a water barrier on the epicuticleand serve as contact pheromones or their biosynthetic precursors in manyinsects. Short-chain HC serve as volatile sex pheromones in someinsects and are common sex pheromone components in tiger moths. Ourin vitro results showed that 2-methylheptadecane and related HC pheromonecomponents are synthe-sized in association with the abdominal integument. A blood transport pathway must therefore be involved. A high densitylipoprotein (lipophorin) was purified and was shown to be the only hemolymphpro-tein that carries the pheromone constituents. Our data thus supportthe hypothesis that lipophorin loads newly synthesized HC pheromone fromthe abdomi-nal integument and transports it to pheromone dispensing glandsin the abdomen. The tubular sex pheromone gland does not synthesizepheromone and appears to function as a nozzle that aerosolizes the pheromoneduring calling behavior.