Effect of long-term rearing of <i>Euseius scutalis</i> (Acari: Phytoseiidae) on cattail pollen on its functional and numerical responses fed on <i>Tetranychus turkestani</i> (Acari: Tetranychidae)

Predatory mites are important biological control agents of spider mites in various crops. Long-term mass rearing on alternative foods, such as plant pollen, may affect their predatory efficiency, but data on <i>Euseius scutalis</i> are scarce. Therefore, this study aimed to evaluate whether long-term rearing of <i>E. scutalis</i> on cattail pollen influences its functional response when fed on <i>Tetranychus turkestani</i>. Functional and numerical responses of the predatory mite <i>E. scutalis</i> reared on cattail (<i>Typha latifolia</i>) pollen over 30 generations on different densities (2, 4, 8, 16, 32, 64, and 128) of <i>T. turkestani</i> were evaluated. The results indicated a type II functional response for <i>E. scutalis</i> on <i>T. turkestani</i> in all generations (G1, G10, G20, and G30) tested. The attack rate (<i>a</i>) of <i>E. scutalis</i> increased as the number of generations increased. The handling time decreased as the number of generations increased from G1 (0.330 h) to G10 (0.318 h), then increased in G20 (0.572 h) and then decreased again in G30 (0.385 h). In G1 and G30, the number of eggs deposited by the predator increased as prey density increased. However, in G10 and G20, egg deposition increased up to 64 prey and then slightly decreased at 128 prey. The results indicated that the quality of <i>E. scutalis</i> did not lessen against <i>T. turkestani</i> after different periods of rearing on cattail pollen. Based on this study, we recommend cattail pollen as a good candidate for the large-scale rearing of <i>E. scutalis</i> for use in biological control programmes against <i>T. turkestani</i>.