The effect of temperature on the functional response and prey consumption of phytoseius plumifer (Acari: Phytoseiidae) on the two-spotted spider mite

Abstract

The purpose of this study was to determine the relationship between prey density and consumption by the mated female of Phytoseius plumifer (functional response) and the voracity of different life stages. The Phytoseius plumifer females were fed on nymphal stages of Tetranychus urticae Koch at four different temperatures (15, 20, 25 and 30oC) and six prey densities (n=2, 4, 8, 16, 32 and 64) for 24 hours. The functional response and prey consumption experiments were carried out at six temperatures (15, 20, 25, 30, 35 and 37oC). The results showed that the functional response of P. plumifer to different densities of Ttetranycus urticae at all temperatures was type II (the proportion of preys consumed declines monotonically with a prey density). The maximum searching efficiency was observed at 25oC (a = 0.059 h-1) and the minimum handling time was observed at 30oC and was calculated as Th = 0.425 h. The number of preys consumed daily and totally by the protonymphal stage increased with increasing temperature from 15oC (0.71 and 3.97, respectively) to 25oC (2.37 and 5.44, respectively) and then decreased until 35oC. The daily prey consumption of the deutonymphs ranged from 1.30 to 5.46 at 15 and 35oC, respectively. The daily prey consumption of the females increased with temperature from 8.85 preys/ day at 15oC to 31.81 preys/ day at 35oC. The total female prey consumption increased with temperature from 218.30 preys at 15oC to 426.98 preys at 25oC.