Effect of different pollens on development, survivorship and reproduction of Euseius finlandicus (Acari: Phytoseiidae)

Development, imaginal survivorship, adult longevity and fecundity of the predatory phytoseiid mite Euseius (Amblyseius) finlandicus Oudemans reared on seven different plant pollens were determined in the laboratory. The rationale behind these experiments was to assess the nutritional value and the possible effect on development and population dynamics of the mite. Mites were kept individually on bean (Phaseolus vulgaris L.) leaf disks at 20 +/- 1 degrees C and a photoperiod of 16:8 (L:D) h, with a sufficient quantity of pollen of apple (Malus silvestris M.), pear (Pyrus communis L.), cherry (Prunus avium L.), peach (Prunus persica L.), apricot (Prunus armeniaca L.), walnut (Juglans regia L.), or poppy (Papaver rhoeas L.). Developmental time from neonate larva to adult emergence varied between the different pollens from 6.03 to 6.62 d for females and from 5.46 to 6.14 d for males. Survivorship during immature development varied from 67.2 to 95.9% with the lowest value recorded on peach pollen. The average life span of adult females reared on the different pollens varied from 18.2 to 56.2 d, whereas the respective total fecundity ranged from 2.5 to 46.5 eggs per female. The estimated values of the intrinsic rate of increase (r(m)) varied from 0.012 to 0.150. The analysis of these results show that cherry, peach, apricot, walnut, and poppy pollens are of higher nutritional value for E. finlandicus than apple and pear pollens and thus may play an important role in the field for sustaining and increasing the predator's population.