Evaluation of aluminum phosphide against wood-destroying insects

Aluminum phosphide, a well-known stored grain fumigant, available in solid formulation, has shown promise as wood fumigant. This chemical decomposes to phosphine when exposed to moisture. The feasibility of fumigant treatment to extend the service life of wood was evaluated in a small block test of two wood species. Hard wood (Mangifera indica L.) and conifer blocks (Pinus roxburghii Sargent) were fumigated with different concentrations (0.05, 0.1, 0.2, 0.4, 0.8, and 1.6%) of aluminum phosphide. Fumigated blocks were exposed to Lyctus africanus Lesne (Coleoptera; Lyctidae) larvae. Results revealed that aluminum phosphide showed complete mortality of Lyctus larvae at 0.2% concentration, that is, 0.93 g/m3 retention level. Mean mortality of 74% of Lyctus larvae was observed in soft wood blocks fumigated with lowest concentration, that is, 0.05% of aluminum phosphide, whereas in hard wood blocks > 85% mortality was observed at this concentration.