Daily consumption and predation rate of differentStethorus punctilluminstars feeding onTetranychus urticae

Laboratory experiments were conducted to evaluate the prey stage preference and the daily consumption of each stage of the coccinellid predatorStethorus punctillumWeise (Coleoptera: Coccinellidae) feeding on the two-spotted spider miteTetranychus urticae(Koch) (Acari: Tetranychidae). Groups of different life stages of the prey were offered (eggs, larvae, nymphs and adults). The prey preference varied with the stage ofS. punctillum. First larval instars had no significant preference among theT. urticaestages offered. Second larval instars consumed significantly more spider mite larvae in comparison with nymphs. In contrast, third larval instars indicated a strong preference for mite eggs. Significantly fewerT. urticaelarvae were consumed by the fourth larval instars ofS. punctillum, in comparison with the three other mite stages. Finally, adult predators consumed significantly more mite eggs than the other stages offered. This preferential trend was similar for all adults tested, whether during the pre-oviposition or the oviposition period.