Prey suitability and life table analysis of Amblyseius swirskii and Amblyseius aerialis (Parasitiformes: Phytoseiidae) on Panonychus citri (Acariformes: Tetranychidae) and Phyllocoptruta oleivora (Acariformes: Eriophyidae)

Abstract

Phytoseiid mites are important predators of several pests including mites and are widely used in enclosed and open crop production systems. We evaluated two phytoseiid species, one that is commercially available (Amblyseius swirskii), and a species found in Florida citrus (A. aerialis), against pest mites Panonychus citri and Phyllocoptruta oleivora. These pests cause significant losses to citrus grown in traditional orchards and enclosed systems such as Citrus Under Protective Screen (CUPS). CUPS is a new undercover system being implemented to produce citrus free of Huanglongbing (HLB) disease and its vector psyllid. Development period, longevity, reproduction, and life table parameters of the two predatory mites were evaluated under laboratory conditions at 22 ± 2 °C and 60 ± 5% RH. Phyllocoptruta oleivora was not suitable for both predatory mites even to complete development through protonymph stage. When fed on P. citri, A. swirskii developed faster than A. aerialis, (8.9 vs. 10.2 days, respectively) and exhibited a shorter pre-oviposition period than A. aerialis (3.6 vs. 5.5 days, respectively) and a longer oviposition period (31.9 vs. 24.1 days, respectively). Fecundity and oviposition rate were also higher for A. swirskii than A. aerialis averaging 43.4 vs. 17.3 eggs/female, respectively, and 1.4 vs. 0.7 eggs/female/day, respectively. The positive effects of feeding on P. citri also improved several life table parameters of A. swirskii compared to A. aerialis. The intrinsic rate of increase, finite rate of increase, and net reproductive rate were all significantly higher for A. swirskii (1.173, 0.16, and 32.52, respectively) than A. aerialis (1.105, 0.10, and 10.71, respectively). Findings suggest that both predatory mites benefited from feeding on P. citri and will be useful for their production and implementation in citrus pest management particularly against P. citri.