Comparison of natural prey Tetranychus turkestani, date palm pollen, and bee pollen diets on development, reproduction, and life table parameters of the predator Amblyseius swirskii

Authors: RAHMANI PIYANI, A - Shahid Chamran University Of Ahvaz; SHISHEHBOR, PARVIZ - Shahid Chamran University Of Ahvaz; KOCHEILI, FARHAN - Shahid Chamran University Of Ahvaz; Riddick, Eric

Submitted to: Acarologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2021
Publication Date: 10/21/2021
Citation: Rahmani Piyani, A., Shishehbor, P., Kocheili, F., Riddick, E.W. 2021. Comparison of natural prey Tetranychus turkestani, date palm pollen, and bee pollen diets on development, reproduction, and life table parameters of the predator Amblyseius swirskii. Acarologia. 61(4):890-900. https://doi.org/10.24349/G9ed-QB9h.
DOI: https://doi.org/10.24349/G9ed-QB9h

Interpretive Summary: One of the greatest challenges to continued growth of the biological control industry is the development of cost-effective diets to mass produce natural enemies (predators and parasitoids) to control plant pests (natural prey). Ongoing research is exploring the potential of using plant pollen-based diets to mass produce predatory mites. Pollen diets are considerably less expensive than natural prey diets. In this study, laboratory experiments tested the effects of natural prey (Tetranychus turkestani) and two pollen diets, i.e., date palm pollen and commercial bee pollen, on development and reproduction of the predatory mite Amblyseius swirskii. Results indicated that total development time was less for predators fed date palm pollen. However, adult longevity and fecundity were greatest for predators fed natural prey. A life table analysis confirmed these results but the intrinsic rate of natural increase was greater for predators fed date palm pollen. Mean generation time and population doubling time were shorter for predators fed date palm pollen. These observations suggest that predators will require less time to increase population size when fed the date palm pollen diet. In conclusion, this study indicates that date palm pollen would be the preferred diet to support cost-effective mass rearing of the predator. Date palm pollen is easily collected, harvested, stored, and inexpensive to purchase. Using the natural prey diet to mass rear the predator would not be cost-effective because maintaining host plants and space to cultivate them as food for natural prey would be prohibitive. This research should benefit the biological control industry by providing an effective plant pollen diet to rear predatory mites such as Amblyseius swirskii.

Technical Abstract: The predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is produced commercially for biological control of tetranychids (spider mites) on crop plants around the world. The aim of this study was to compare the effects of a diet of natural prey, Tetranychus turkestani Ugarov and Nikolskii (Acari: Tetranychidae), date palm pollen, or bee-collected pollen on A. swirskii development, reproduction, and life table parameters. Completely randomized, no-choice experiments were conducted in replicated experimental units, i.e., 3 x 3 cm plastic sheets inside Petri dishes. A life table analysis was also conducted. Results indicated that diet type did not affect A. swirskii preimaginal survival; it ranged from 97-100% on T. turkestani and both pollen diets. However, total development time was significantly shorter for A. swirskii females fed date palm pollen than T. turkestani or bee pollen. Adult females fed T. turkestani lived longer, had longer oviposition periods, and produced more eggs. The intrinsic rate of natural increase (0.396 d-1) was higher for A. swirskii fed date palm pollen than T. turkestani or bee pollen. The finite rate of increase, net reproductive rate, and gross reproductive rate did not differ significantly between A. swirskii fed date palm pollen or T. turkestani. Mean generation time (7.56 d) and population doubling time (1.043 d) were shorter for A. swirskii fed date palm pollen than T. turkestani or bee pollen. This study suggests that the T. turkestani diet or date palm pollen diet is suitable for A. swirskii. Date palm pollen has great potential as a cost effective diet to mass produce A. swirskii in the absence of natural prey. Future research could determine whether long-term rearing on date palm pollen reduces the ability of A. swirskii to locate, capture, and consume T. turkestani or other Tetranychus species on crop plants.