Susceptibility to contact insecticides of granary weevil Sitophilus granarius (L.) (Coleoptera: Curculionidae) originating from different locations in the former Yugoslavia

Variation in susceptibility of laboratory and field strains of three stored‐grain insect species to β‐cyfluthrin and chlorpyrifos‐methyl plus deltamethrin applied to concrete surfaces

“…The probit regression slopes were 1.2–3 times higher for grain assays indicating greater susceptibility than filter paper assays . Field strains of the granary weevil, Sitophilus granarius (L.), from different locations in the former Yugoslavia were 0.5 to 30 times less susceptible to the organophosphates dichlorvos, malathion, chlorpyrifos‐methyl, and pirimiphos‐methyl, and to the pyrethroids deltamethrin and cypermethrin than the laboratory strain based on discriminating‐dose tests with treated filter papers …”

“…All of the studies mentioned earlier were conducted using laboratory reared stored‐grain insects. Field collected insects may differ markedly from laboratory strains in their susceptibility to insecticides applied to empty bins and grains due to natural tolerance or resistance . To date, there are no published studies documenting effectiveness of β ‐cyfluthrin and chlorpyrifos‐methyl plus deltamethrin on concrete surfaces similar to that of empty bins against field strains of stored‐grain insect populations.…”

Residual efficacy of cypermethrin and pirimiphos-methyl against Sitophilus granarius (L.) and Plodia interpunctella (Hübner) on concrete surface

“…For example, exposing S. granarius insects from their laboratory population to treated filter paper for 48 h, Kljajić and Perić (2006) had found that 50% and 95% mortality of adults required cypermethrin application rates of 135 mg/m 2 and 732 mg/m 2 without the synergist piperonyl butoxide added. Collins (1990) had exposed a laboratory population of red flour beetles Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) to treated wheat grain for 26 days and measured cypermethrin toxicity of 0.34 mg/kg (LC 50 ) and 1.2 mg/kg (LC 95 ), while Athanassiou et al (2004) had tested residual efficacy of a cypermethrin isomer (alpha-cypermethrin) in wheat grain against rice weevils Sitophilus oryzae (L.) on 30-and 60-day old deposits after seven days of exposure and detected 33-50% efficacy of alpha-cypermethrin (0.25 mg/kg).…”

Pyrethroid Resistance in Populations of <I>Listronotus maculicollis</I> (Coleoptera: Curculionidae) From Southern New England Golf Courses

“…Mexican (Perez-Mendoza 1999) and Brazilian (Guedes et al 1995, Ribeiro et al 2003 populations of the maize weevil, Sitophilus zeamais Motschulsky, have been found to be resistant to deltamethrin and permethrin. Yugoslavian populations the grain weevil, Sitophilus granarius (L.), have demonstrated resistance to deltamethrin and cypermethrin (Kljajic and Peric 2006), and strains of the rice weevil, Sitophilus oryzae (L.), exhibit the ability to develop resistance to pyrethroids under laboratory conditions (Heather 1986).…”