Demographic and predatory parameters of a thelytokous phytoseiid mite as a biocontrol agent for spider mites

The phytoseiid mite Neoseiulus agrestis (Karg) was recently collected from tetranychid-damaged maize plants in northwest China. The demographic parameters and functional response of N. agrestis were studied to evaluate its potential against spider mites.

Starting with the capture of a solitary female mite, a laboratory population of N. agrestis was successfully established over multiple generations without any males being found. The life table experiment confirmed that N. agrestis indeed reproduced through thelytokous parthenogenesis and exhibited high fitness levels in both development and reproduction on four different diets consisting of spider mites Tetranychus urticae Koch and T. truncatus Ehara, astigmatid mites Aleuroglyphus ovatus (Tropeau), and cattail pollen Typha sp. The predator that preyed on two natural prey species exhibited a higher intrinsic rate of increase (T. urticae: 0.2501 day^-1; T. truncatus: 0.2464 day^-1). The functional responses of N. agrestis to different immature stages of T. urticae showed significantly higher average consumption rates (24.56 prey day^-1) for larvae compared to other stages. Logistic regression analysis revealed that N. agrestis displayed a type II functional response across all immature stages of T. urticae, with the consumption rate increasing as prey density increased, until reaching a peak and eventually stabilizing at the plateau.

The enhanced fitness of N. agrestis on both prey and pollen, along with its high consumption rate on tetranychid mites, highlights the potential of this thelytokous predator as a promising biocontrol agent and provides a novel approach for the management of spider mites in China. © 2025 Society of Chemical Industry.