Login | Create Account (DAF staff only)

Development of a Quick Knockdown Test for Diagnosing Resistance to Phosphine in Sitophilus oryzae (Coleoptera: Curculionidae), a Major Pest of Stored Products

Nayak, M. K., Daglish, G. J., Pavic, H., Jagadeesan, R., Kaur, R. and Phillips, T. W. (2019) Development of a Quick Knockdown Test for Diagnosing Resistance to Phosphine in Sitophilus oryzae (Coleoptera: Curculionidae), a Major Pest of Stored Products. Journal of Economic Entomology, 112 (4). pp. 1975-1982.

Full text not currently attached. Access may be available via the Publisher's website or OpenAccess link.

Article Link(s): https://doi.org/10.1093/jee/toz085

Abstract

A key component in the management of resistance to fumigant phosphine in stored products pests is their early detection and implementation of control strategies. Currently, resistance testing involves exposing adults to a specific discriminating concentration over a fixed time period (20–48 h). Although it is widely adopted, this test takes significant time for assay preparation (up to 4 wk) as well as diagnosis (1–2 wk). To address these lacunae, we have established a ‘quick knockdown test’ using a key grain insect pest, rice weevil, Sitophilus oryzae (L.). Susceptible, weakly and strongly phosphine-resistant reference strains were exposed to a threshold concentration of phosphine over short exposure periods (min to h). The time to knockdown (KT) responses to phosphine were characterized at 2 (1,440 ppm) and 5 mg/liter (3,600 ppm). The time to 99.9% KT (KT99.9) at 2 mg/liter was 12.52 min for the susceptible adults, compared with 167.9 and 1,510 min in the case of weakly and strongly resistant phenotypes, respectively. As anticipated, increasing the concentration of phosphine to 5 mg/liter halved the KT99.9 (81.57 min) to separate weakly and strongly resistant populations than it was required at 2 mg/liter. We validated the KT99.9 value for the 5 mg/liter against field-derived populations of S. oryzae. The results were aligned with the existing Food and Agriculture Organization approach, confirming that the proposed ‘quick test’ is a reliable tool to rapidly diagnose resistance in this species.

Item Type:Article
Business groups:Crop and Food Science
Keywords:strong resistance, rapid assay, discriminating dose, fumigation bioassay
Subjects:Plant culture > Field crops > Grain. Cereals
Plant pests and diseases > Economic entomology
Plant pests and diseases > Pest control and treatment of diseases. Plant protection
Deposited On:09 May 2019 01:48
Last Modified:02 Sep 2019 05:47

Repository Staff Only: item control page