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The hydrodynamics of a continuous-flow stirred tank reactor (CFSTR) have been studied through RTD measurements, visual tracing, and CFD simulations, for an axial-flow and two radial-flow impellers (Mixel TT and Rushton and NS turbines), to investigate how the combination of impeller choice and operating conditions (flow rates, agitator speed) affect the vessel hydrodynamics and flow nonideality. The portion of the total vessel volume being perfectly mixed decreases considerably as the vessel utilization is forced by decreasing the vessel retention time; at the same time the amount of feed bypassing/short-circuiting increases, too, especially in the case of axial-flow impellers. Qualitative and quantitative results are obtained, leading to conclusions about the suitability of particular impeller−vessel configuration combinations.

Phytoseiid mites of the genus Phytoseius are natural enemies of tetranychid and eriophyid herbivorous mites mostly found on hairy plants where they feed on prey, as well as on pollen. Nevertheless, the nutritional ecology and the role of these predators in biological pest control are only rarely addressed. In the present study, we evaluated the potential of Phytoseius finitimus to feed and reproduce on three major greenhouse pests, the two-spotted spider mite, the greenhouse whitefly and the western flower thrips. Additionally, we estimated the effect of cattail pollen when provided to the predator alone or in mixed diets with prey. Contrary to thrips larvae, both spider mite larvae and whitefly crawlers sustained the development of P. finitimus. In addition, females consumed more spider mite eggs and larvae, as well as whitefly crawlers than thrips larvae, but laid eggs when feeding on all prey. When provided alone, cattail pollen sustained the development and reproduction of the predator. The addition of pollen in mixed diets with prey reduced prey consumption, though it increased the predator's egg production. We discuss the implications of our findings for biological pest control.

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