[Title: An aeroplane dusting experiment for the control of spruce bud worm carried out at Westree on June 1929]: AERIAL SHOT over forest. HAS full frame over evergreen trees in forest. CU of budworms moving on evergreen tree branch. AERIAL SHOTs over infested forest. Several shots of infested trees where defoliation is evident. CU PAN along branches showing damage caused by budworms. MS of two entomologists working in tent. CUs of mounted specimens of spruce budworms in various stages of growth. CU of illustration depicting two birds eating budworms. AERIAL SHOT over entomologists' camp. MLS of men rolling barrels of poison. MS of entomologists in camp. Sequence showing Ford Trimotor being towed to mooring, of aircraft being prepared for flight, FOLLOW MLS of Trimotor taking off. Sequence on wooden tower being built for servicing of plane. Sequence on Trimotor landing, men unloading plane into outboard, boat moving away by camera. BOATING SHOT along camp. [titles interspersed]