Preliminary study to evaluate ethanedinitrile (C₂N₂) for quarantine treatment of four wood destroying pests

BACKGROUND: Methyl bromide is an ozone depleting substance and is still being used for quarantine treatment of wood products and logs. Ethanedinitrile (C₂N₂) is a new potential alternative fumigant and has been investigated as a timber fumigant because it has shown better penetration through timber and responds fast to insects and nematodes. This article reports on laboratory and commercial-scale trials with C₂N₂ for important wood destroying pests namely Tomicus piniperda (Pine bark beetle) adults, Hyphantria cunea (Fall webworm) lavae, Reticulitermes speratus (Japanese Termite) adults and Cryphalus fulvus (Scolytidae) (Yellow minute bark beetle) which naturally infests pine logs. RESULTS: Tomicus pi:niperda adults were more tolerance than H. cunea lavae and R. speratus adults with lethal concentration × time affecting 99% mortality (LCt₉₉) values of 27.84, 7.49 and 3.30 g h m⁻³, respectively. Ethanedinitrile shows exceptionally high toxicity to adult R. speratus which was almost 26 times more toxic than methyl bromide. The complete control of larvae and adults stages of C. fulvus was achieved at concentration × time (Ct) products from 89.6 g h m⁻³ in a 6–8 L fumigation chamber. Temperature-depending trials on C. fulvus were conducted with C₂N₂ doses of 30 at 21 ± 6 and 40 g m⁻³ at 9 ± 3 and 2 ± 2 °C for 24 h. The Ct products of 182.2, 227.8 and 268.6 g h m⁻³ were obtained and C. fulvus was completely controlled at all tested temperatures. CONCLUSION: Ethanedinitrile could offer quarantine treatment for wood products and logs for the control of wood destroying insect pests and termites.