Effectiveness of methyl bromide as a cargo fumigant for brown treesnakes

The effectiveness of methyl bromide as a fumigant for brown treesnake (Boiga irregularis) management was evaluated on Guam. Eighteen snakes in secured cloth bags were randomly positioned in a 47.7-m³ tarpaulin-covered cargo container for each fumigation treatment. Methyl bromide treatments tested were: 24 g m⁻³ and and 12 g m⁻³, both for 2-h and 1-h exposures. All treatments, except for 12 g m⁻³ for 1 h, resulted in 100% mortality. Two-hour exposures to methyl bromide at 24 and 12 g m⁻³ appear to be effective in killing brown treesnakes within reasonable time-frames for shippers under Guam field conditions.