Evaluation of Natural and Factitious Food Sources for Pronematus ubiquitus on Tomato Plants

Abstract

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.

Potential of two omnivorous iolinid mites as predators of the tomato russet mite, Aculops lycopersici

“…Our results corroborate earlier reports that pollen is an excellent food source for H. anconai and P. ubiquitus (Duarte et al 2021;Flaherty et al 1971;Hessein et al 1988;Knop et al 1983). Duarte et al (2021) reported that pollen needs to be supplemented at least every other week to allow a sufficient population build-up of P. ubiquitus in tomatoes. Whether pollen supplementation needs to be continued even when A. lycopersici is present in the crop remains to be investigated in greenhouse conditions.…”

“…Hessein et al (1988) reported some reproduction of H. anconai on a plastic substrate when offered A. lycopersici alone or A. lycopersici with cattail pollen, but the availability of leaf tissue clearly enhanced population development. Duarte et al (2021) reported that P. ubiquitus females taken from the massrearing units and allowed to lay eggs for four days on a tomato leaf-only diet produced less than 0.5 eggs/female/day. However, this reproductive output may result from their food uptake during the rearing.…”

“…The preventive establishment of a predator to create a 'standing army' against A. lycopersici offers a solution to this problem (Pijnakker et al 2021). The suitability of pollen as a diet may increase the potential of biological control agents by enabling them to pre-establish well in the crop before the pest is present and to sustain their population when pest densities are low, as well as by making mass-production easier and cheaper (Duarte et al 2021;McGregor et al 2020). Our results corroborate earlier reports that pollen is an excellent food source for H. anconai and P. ubiquitus (Duarte et al 2021;Flaherty et al 1971;Hessein et al 1988;Knop et al 1983).…”

“…The suitability of pollen as a diet may increase the potential of biological control agents by enabling them to pre-establish well in the crop before the pest is present and to sustain their population when pest densities are low, as well as by making mass-production easier and cheaper (Duarte et al 2021;McGregor et al 2020). Our results corroborate earlier reports that pollen is an excellent food source for H. anconai and P. ubiquitus (Duarte et al 2021;Flaherty et al 1971;Hessein et al 1988;Knop et al 1983). Duarte et al (2021) reported that pollen needs to be supplemented at least every other week to allow a sufficient population build-up of P. ubiquitus in tomatoes.…”

Potential of two omnivorous iolinid mites as predators of the tomato russet mite, Aculops lycopersici

“…This difference could be related to the plastic substrate used in the study by Hessein et al (1988) reported some reproduction of H. anconai on a plastic substrate when offered A. lycopersici alone or A. lycopersici with cattail pollen, but the availability of leaf tissue clearly enhanced population development. Duarte et al (2021) reported that P. ubiquitus females taken from the mass-rearing units and allowed to lay eggs for four days on a tomato leaf-only diet produced less than 0.5 eggs/female/day. However, this reproductive output may be the result of their food uptake during the rearing.…”