Comparative age-stage, two-sex life table analysis of native and abamectin and bifenazate-resistant populations of amblyseius swirskii athias-henriot (Acari: Phytoseiidae) under laboratory conditions

Abstract

Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is an effective biocontrol agent used against whiteflies, thrips, and spider mites in crops. This study assessed the effects of an acaricide of abamectin + bifenazate mixture on the life tables of native (NP) and acaricide-resistant (S6) populations of A. swirskii under controlled conditions in growth chambers set to 28 +/- 1 degrees C, 80 +/- 5 % relative humidity, and a 16:8 h light:dark photoperiod. The S6 population, with 25-fold resistance to abamectin+bifenazate, was developed from NP through six selections. Life history and population growth parameters were analyzed under untreated and acaricide-treated conditions at the recommended concentration. Under untreated conditions, developmental durations were similar between S6 and NP, but S6 females had longer lifespans, higher fecundity, and longer oviposition periods. The intrinsic rate of increase (r), net reproductive rate (R0), and finite rate of increase (7) were not significantly different between S6 and NP. Under acaricide-treated conditions, S6 females had longer lifespans and oviposition periods, with significantly higher fecundity. The reproductive parameters R0, r, and 7 were higher in S6 than NP. These results suggest that resistance to abamectin and bifenazate did not negatively impact the fitness components of A. swirskii, providing valuable insights for integrated pest management (IPM) programs.