ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Efficacy of diflubenzuron plus methoprene against Sitophilus oryzae and Rhyzopertha dominica in stored sorghum

Gregory J. Daglish, and Barry E. Wallbank

Journal of Stored Products Research Volume 41, Issue 3, 2005, Pages 353-360

2005

บทคัดย่อ

The efficacy of diflubenzuron (1 mg kg^-1)+ methoprene (1 mg kg^-1) against Sitophilus oryzae (L.) and Rhyzopertha dominica (F.) in sorghum was evaluated in a silo-scale trial in southeast Queensland, Australia. Sorghum is normally protected from a wide range of insects by mixtures of grain protectants. The chitin synthesis inhibitor diflubenzuron was evaluated as a potential new protectant for S. oryzae in combination with the juvenile hormone analogue methoprene, which is already registered for control of R. dominica. Sorghum (ca 200 t) was treated after harvest in 2000 and assessed for treatment efficacy and residue decline during 6.5 months storage. The reproductive capacity of S. oryzae and R. dominica was greatly reduced in bioassays of treated sorghum throughout the trial, and efficacy remained relatively stable during the trial. An initial exposure of S. oryzae adults to treated sorghum for 2 weeks reduced F1 progeny production of all strains by 80.8–98.8%, but a second exposure of 4 weeks reduced F1 progeny production by 98.5–100%. In addition, the reproductive capacity of any S. oryzae progeny produced was greatly reduced. Exposure of R. dominica adults to treated sorghum for 2 weeks reduced F1 progeny production of all strains by 99.6–100%, including a methoprene-resistant strain. The results indicate that S. oryzae or R. dominica adults invading sorghum treated with diflubenzuron (1 mg kg^-1) +methoprene (1 mg kg^-1) would be incapable of producing sustainable populations.