Suitability of food resources for Proprioseiopsis mexicanus, a potentially important natural enemy in eastern USA agroecosystems

The phytoseiid Proprioseiopsis mexicanus has been collected from a wide range of plants in the western hemisphere, including many cucurbit agroecosystems in South Carolina, USA. Our aim was to characterize the lifestyle of P. mexicanus and its potential as a natural enemy of Tetranychus urticae, a common pest in cucurbits. We determined developmental time, pre-oviposition time, and fecundity of females on pollen-only diets from a commercial Typha spp. supplement source, Citrullus lanatus, Cucurbita maxima, Cucurbita moschata, Cucurbita pepo, Delosperma cooperi, Trifolium incarnatum, and on T. urticae and a combination of T. urticae and Typha spp. pollen. Female development time differed based on diet-development was fastest on C. lanatus and D. cooperi diets (ca. 3 days) and slowest on Typha pollen diet (ca. 5 days). Pre-oviposition time was shorter for females fed C. lanatus and T. incarnatum (1.6 days) and longest when fed Typha pollen (3.1 days). Citrullus lanatus, T. incarnatum, and D. cooperi pollen diets resulted in more eggs/day compared to other diets. Cucurbita moschata pollen resulted in the lowest oviposition rate (0.69 eggs/day). Because these pollens varied in size, we examined pollen size as a factor in developmental and reproductive success. With the exception of Typha pollen, small-pollen diets (C. lanatus, D. cooperi, and T. incarnatum) resulted in faster development, shorter pre-oviposition time, and higher fecundity than large-pollen diets (Cucurbita spp.). We concluded that P. mexicanus is a generalist predator that may require pollen for survival and reproduction, but alone this species may not be an effective predator of T. urticae.

Automated summary

The study found that the phytoseiid Proprioseiopsis mexicanus responds differently to different types of pollen, with some pollen diets improving its egg-laying ability, particularly small-pollen diets. However, when it comes to preying on Tetranychus urticae, Proprioseiopsis mexicanus may not be very effective as a predator.