Effects of Citrullus colocynthis mediated silver nanoparticles against toxicity and demographic characteristics of the Oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae)

Bactrocera dorsalis is a major destructive pest in the Asia-Pacific regions because of its very broad range of host plants. Due to indiscriminate application of pesticides, the B. dorsalis has developed resistance to insecticides. The phytosynthesized AgNPs have potential for application as an alternative to synthetic pesticides in the management of B. dorsalis infestations. Therefore, in this study we examined the toxicity of Citrullus colocynthis-synthesized AgNPs against B. dorsalis and their effects on life table parameters. The results revealed that AgNPs are face-centric in nature, having an average size of 37 nm. Fourier transform infrared (FT-IR) analysis identified different bioactive compounds that helped in the reduction of Ag ions into AgNPs. The toxicity bioassay results confirmed that phytosynthesized Cc-AgNPs caused higher mortality than other tested treatment, and the LC₅₀ values of Cc-AgNPs were 0.270 g/L for larvae and 0.0.413 g/L for adults. These concentrations were subsequently applied in investigating the demographic profiles of B. dorsalis. In comparison with the control and standard trichlorfon treatment, immature duration and adult longevity were significantly increased by Cc-AgNPs. The key population parameters, such as intrinsic rate of increase (r = 0.1026 d⁻¹), finite rate of increase (λ = 1.1081 d⁻¹) and net reproductive rate (R_o = 121.12 offspring), were significantly lower in the Cc-AgNPs. In addition, the fecundity of female B. dorsalis was decreased considerably in Cc-AgNPs. In conclusion, phytosynthesized Cc-AgNPs exhibit potential as an innovative Integrated Pest Management (IPM) tool for controlling B. dorsalis populations.