Multiple Pesticide Resistance in Rust-Red Flour Beetle (Tribolium castaneum, Herbst 1797) from Northern Nigeria Is Probably Driven by Metabolic Mechanisms

Abstract

There is a severe lack of information about molecular mechanisms of pesticide resistance in the rust-red flour beetle, a major pest destroying grains and flour across Nigeria, hindering evidence-based control. Here, we identified to the species level three populations of the red flour beetle from Kano, Nigeria, as Tribolium castaneum (Herbst 1797) and investigated the mechanism driving their insecticide resistance. The IRAC susceptibility bioassays established cypermethrin resistance, with LC50s of 4.35–5.46 mg/mL in the three populations, NNFM, R/Zaki and Yankaba. DDT and malathion resistance were observed in NNFM, with LC50s of 15.32 mg/mL and 3.71 mg/mL, respectively. High susceptibility was observed towards dichlorvos in all three populations with LC50s of 0.17–0.35 mg/mL. The synergist bioassay with piperonylbutoxide significantly restored cypermethrin susceptibility, with mortality increasing almost threefold, from 24.8% obtained with 1.5 mg/mL of cypermethrin to 63.3% in the synergised group (p = 0.013), suggesting a preeminent role of P450s. The two major knockdown resistance (kdr) mutations, T929I and L1014F, in the IIS4 and IIS6 fragments of the voltage-gated sodium channel were not detected in both cypermethrin-alive and cypermethrin-dead beetles, suggesting a lesser role of target-site insensitivity mechanisms. These findings highlight the need to explore alternative control tools for this pest and/or utilise synergists, such as piperonyl butoxide, as additional chemistries in pesticide formulations to improve their efficacy.

Biosynthesis of Copper Nanoparticles from Acacia cornigera and Annona purpurea and Their Insecticidal Effect against Tribolium castaneum

“…On the other hand, multiple resistance towards two different classes of insecticides (pyrethroid and organophosphate) has been reported in the Brazilian population of the red flour beetle [8]. Similar results have been reported in the Nigerian population, which was resistant to dichlorvos, cypermethrin, DDT, and malathion [9]. This resistance involves the presence of different mechanisms of insecticide resistance, for example, T. castaneum treated with malathion showed that the induction of the antioxidant enzyme catalase could have helped to withstand oxidative stresses, contributing to increased immunity of the insecticide [10].…”

“…For the biosynthesis of metallic nanoparticles, aqueous solution from each plant was mixed with 10 mM copper sulfate (CuSO4) and water relation 1:4 v/v [16]. To evaluate the effect of temperature (30,40, 50 • C), pH (5,7,9), concentration of extract of each plant (50, 75, 100%), and reaction time (20, 30, and 40 min) in the bio reduction process of CuNPs, an orthogonal experimental was designed (Table 1). The variable considered for the optimal conditions was the T. castaneum mortality response.…”