Abstract
Simple SummaryBiocontrol practitioners have increasingly released generalist predators to control a variety of greenhouse pests. In this study, the effects of alternative food sources on the oviposition rate and the population dynamics of the mite Pronematus ubiquitus were assessed. The alternative food sources were selected among those the mite may encounter or be applied to the tomato crop.Pronematus ubiquitus (McGregor) is a small iolinid mite that is capable of establishing on tomato plants. Once established, this mite has been shown to control both tomato russet mite, Aculops lycopersici (Tryon) (Acari: Eriophyidae), and tomato powdery mildew (Oidium neolycopersici L. Kiss). In the present study, we explored the effects of a number of alternative food sources on the oviposition rate in the laboratory. First, we assessed the reproduction on food sources that P. ubiquitus can encounter on a tomato crop: tomato pollen and powdery mildew, along with tomato leaf and Typha angustifolia L. In a second laboratory experiment, we evaluated the oviposition rate on two prey mites: the astigmatid Carpoglyphus lactis L. (Acari: Carpoglyphidae) and the tarsonemid Tarsonemus fusarii Cooreman (Acari: Tarsonemidae). Powdery mildew and C. lactis did not support reproduction, whereas tomato pollen and T. fusarii did promote egg laying. However, T. angustifolia pollen resulted in a higher oviposition in both experiments. In a greenhouse trial on individual caged tomato plants, we evaluated the impact of pollen supplementation frequency on the establishment of P. ubiquitus. Here, a pollen addition frequency of every other week was required to allow populations of P. ubiquitus to establish.
Highlights
In contrast to the long-held conviction that specialist natural enemies are required to guarantee effective pest control [1], biocontrol practitioners have been increasingly releasing generalist predators to control a several of greenhouse pests [2,3]
Unlike on cucumber and pepper, phytoseiid predatory mites have difficulties building up populations on tomato crops, even when having access to prey food shown to be suitable in laboratory trials, such as the tomato russet mite (TRM), Aculops lycopersici (Tryon) (Acari: Eriophyidae), and several species of whiteflies [24–26]
The oviposition of P. ubiquitus was influenced by the different food sources (Figure 3: generalized linear models (GLMs), F2,39 = 100.8; p < 0.001)
Summary
In contrast to the long-held conviction that specialist natural enemies are required to guarantee effective pest control [1], biocontrol practitioners have been increasingly releasing generalist predators to control a several of greenhouse pests [2,3]. Generalist phytoseiid predatory mites, such as Amblyseius swirskii (Athias-Henriot), Neoseiulus californicus (McGregor), and Neoseiulus cucumeris (Oudemans), are among the most commercialized arthropod biocontrol agents worldwide [16,17], and have been introduced in a wide range of crops, mostly in protected cultivation. In protected crops such as pepper and cucumber, phytoseiids successfully control thrips, whiteflies, and spider mites [18–23]. In addition to plant-provided food sources and prey, these mites are known to feed on fungi [34,35] This predatory mite was found to effectively control two key problems on tomato crops: TRM, A. lycopersici, and powdery mildew This predatory mite can be pre-established and build up large populations by supplementing tomato plants with Typha sp. pollen [3,31]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
