Effects of time and concentration on mortality of phosphine-resistant Sitophilus oryzae (L) fumigated with phosphine

• Published in: Pest management science 2002-10, Vol.58 (10), p.1015-1021
• Main Authors: Daglish, Gregory J, Collins, Patrick J, Pavic, Hervoika, Kopittke, Rosemary A
• Format: Article
• Language: English
• Subjects: adult mortality; Algorithms; Animals; Biological and medical sciences; Coleoptera - drug effects; Coleoptera - growth & development; Dose-Response Relationship, Drug; Drug Resistance; Fundamental and applied biological sciences. Psychology; Invertebrates; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Oryza - parasitology; Pests of stored products; phosphine; Phosphines - administration & dosage; Phosphines - toxicity; Plant Diseases - parasitology; Pupa - drug effects; Pupa - growth & development; resistance; Sitophilus oryzae; Time Factors; time to population extinction; Toxicity Tests
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.532

The effects of exposure period and phosphine concentration on mortality of susceptible and resistant Sitophilus oryzae (L) were investigated. Although S oryzae is one of the world's most serious pests of stored grain there are few data on the practical significance of phosphine resistance in this species. The strains investigated were an Australian susceptible strain, a homozygous resistant strain exhibiting a level of resistance common in Australia and an unselected field strain from China with a much stronger resistance. Fumigations were carried out at 25 °C on adults and mixed‐age cultures. For adults of all three strains and mixed‐age cultures of the susceptible and resistant Australian strains, the relationship between concentration and time could be described by equations of the form Cnt = k. In all cases n