Abstract
The lifetime-dependent functional response and predation rate of Phytoseiulus persimilis Athias-Henriot on eggs of the two-spotted spider mite, Tetranychus urticae Koch was determined under laboratory conditions using cucumber leaf discs. Densities of 2, 4, 8, 16, 32, 64 and 128 prey were offered to 4 (protonymph), 5 (deutonymph), 6 (1-day-old adult), 10 (5-day-old adult), 15 (10-day-old adult), 20 (15-day-old adult), 25 (20-day-old adult), 30 (25-day-old adult), 35 (30-day-old adult) and 40 (35-day-old adult) P. persimilis individuals. The results of logistic regression analyses showed that on the 15th, 35th and 40th days of predator age, predation rate of T. urticae eggs increased, resulting in the type III functional response, while at the other ages, the functional response was type II. The Rogers model was used to estimate searching efficiency (a) and handling time (Th). The longest handling time was obtained in the protonymphal stage with 2.377 +/- 0.192 h. The shortest handling time and the highest value of estimated maximum attack rate (T/Th) were estimated at the age of 20 days (0.494 +/- 0.009 h and 48.57prey/day). At the highest prey density used (128 eggs), our findings showed that the highest number of prey was eaten by 15, 20, 25 and 30 days old P. persimilis (39.3, 41.7, 39.3 and 38.1 eggs per day, respectively). The results of this study revealed that P. persimilis especially at the middle and late ages has a good predation potential on T. urticae eggs at higher prey densities.
Highlights
Predatory mites in the family of Phytoseiidae have gained much attention, because of their important role in biological control of mite and insect pests, there are intensive studies about the distribution, biology, ecology and behavioral characteristics of mites of this family (Fathipour and Maleknia, 2016)
Our findings revealed P. persimilis can show both type II and type III functional responses depending on the age of the predator supporting the hypothesis that a single predator or parasitoid species is able to exhibit different responses depending on its age
Immature stages of P. persimilis had a type II functional response to the density of prey eggs. This was in line with the findings of Fernando & Hassell (1980) for protonymphs and deutonymphs of P. persimilis
Summary
The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is a cosmopolitan agricultural pest, feeding on more than 1100 plant species, of which more than 150 have economic value (Bolland et al, 1998; Migeon et al, 2011; Sedaratian et al, 2011; Khanamani et al, 2013; Maleknia et al, 2016a).Predatory mites in the family of Phytoseiidae have gained much attention, because of their important role in biological control of mite and insect pests, there are intensive studies about the distribution, biology, ecology and behavioral characteristics of mites of this family (Fathipour and Maleknia, 2016). The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is a cosmopolitan agricultural pest, feeding on more than 1100 plant species, of which more than 150 have economic value (Bolland et al, 1998; Migeon et al, 2011; Sedaratian et al, 2011; Khanamani et al, 2013; Maleknia et al, 2016a). Phytoseiulus persimilis Athias-Henriot is one of the most important phytoseiid species that has been known as a very efficient biological control agent of several species of spider mites How to cite this article Fathipour Y. et al (2018), Age-specific functional response and predation capacity of Phytoseiulus persimilis (Phytoseiidae) on the two-spotted spider mite. Owing to the ability of P. persimilis to control spider mites, it is being mass produced and sold by many commercial biological control companies
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