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Keywords
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phytoseiid mite, predation rate, foraging behavior, searching efficiency, handling time
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Abstract
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The age-specific functional and numerical responses of Neoseiulus cucumeris Oudemans (Mesostigmata
Phytoseiidae) on eggs of the two-spotted spider mite, Tetranychus urticae Koch (Prostigmata: Tetranychidae),
were assessed in the laboratory using bean leaf discs. Densities of 2, 4, 8, 16, 32, 64, and 128 prey were provided to 4- (protonymph), 6- (deutonymph), 8-, 13-, 18-, 23-, 28-, 33-, and 40-d-old N. cucumeris individuals.
The functional response of 28- and 40-d-old N. cucumeris fitted type II, whereas the other ages displayed a
type III functional response. The longest handling time observed at the age of 4 d was 0.515 h, whereas the
shortest handling time and highest value of maximum attack rate (T/Th) were associated with the age of the
28-d-old treatment (0.261 h and 91.95 prey/d, respectively). The numerical response of N. cucumeris showed a
significant increase with increasing prey density, but its rate gradually decreased at higher densities. Therefore,
the efficiency of conversion of ingested food was relatively higher at low two-spotted spider mite densities,
whereas it was reduced at high two-spotted spider mite densities. The stronger functional response and predation capacity of N. cucumeris on two-spotted spider mite eggs indicated the high potential of this predatory
mite as an effective biological control agent against two-spotted spider mite especially at its early and middle
ages and also when higher prey densities are present.
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