Laboratory Tests with a Mixture of Carbon Disulfide and Carbon Tetrachloride for Quarantine Control of Larvae of Megastigmus Spp. and Cecidomyiidae in Conifer Seeds124

Abstract

In laboratory tests in 1966-70, conifer seeds infested with larvae of Megastigmus spp. or 3 species of Cecidomyiidae were fumigated with carbon disulfide (CS2): carbon tetrachloride, 1:5 by weight (Vertifume®). In 24-hour fumigations at normal atmospheric pressure (NAP) and 21.6-26.7°C larvae of M. strobilobius (Ratzeburg) in seeds of Picea spp. survived after fumigation at a dosage of 32 mg/liter of CS2 in the mixture, while Craneiobia lawsonianae de Meijere on seeds of Chamaecypais lawsoniana (A. Murray) Parlatore survived at 48 mg/liter Larvae of M. chamaecyparidis Kamijo, Craneiobia lawsonianae, and Janetiella siskiyou Felt survived after fumigation with 48 mg/liter of methyl bromide (MB) for 4 hours under reduced pressure of 125 mm mercury at 21.6-26.7°C. J. siskiyou also survived 16 mg/liter of MB for 24 hours at NAP. Effective dosages with the mixture were at or above 54 mg/liter of CS2 for the larvae of all species tested.