Comparison of N. californicus life table parameters on different diets revealed that the almond pollen (and after that the maize pollen) was a more suitable diet than the others. These findings will be useful in developing appropriate strategies for conservation of N. californicus to control spider mites. © 2016 Society of Chemical Industry.

No abstract

Long-term feeding effects of the almond pollen on the life table parameters of Neoseiulus californicus McGregor were assessed after 5, 10, and 20 generations after introduction in the rearing arena. Furthermore, to evaluate behavioral characteristics of the mass-reared predator (strain A) in face with the real prey, functional and numerical responses of the predator to different densities of the twospotted spider mite nymphs were determined, and the obtained data were compared with those reared on twospotted spider mite (strain T). Long-term rearing did not significantly affect total fecundity of N. californicus (ranged from 37.79 to 41.91 eggs). Nevertheless, preadult duration in the 5th generation was significantly longer than the 10th and 20th generations. The intrinsic rate of increase (r) in the 10th (0.2056 d-1) and 20th (0.2201 d-1) generations had not significant difference together. However, the r value slightly dropped in the 5th generation (0.1706 d-1) because of the irregular offering of fresh pollen to the rearing colonies before that. Both strains of N. californicus exhibited a type II functional response; however, the N. californicus reared on the almond pollen (strain A) had a higher attack rate (a) and shorter handling time (Th). The individuals reared on the almond pollen had a greater size than those reared on twospotted spider mite; its higher predation potential is probably due to this characteristic. Consequently, the rearing of N. californicus on the almond pollen positively affected its attributes including high survivorship, body size, and fecundity, and subsequently higher potential to control twospotted spider mite.

Supply of alternative food is generally thought to enhance the performance of generalist predatory mites. The effects of three different pollens (maize, date palm, and bee-collected pollen) as supplementary diets on the life table and predation capacity of Neoseiulus californicus McGregor (Acari: Phytoseiidae) on two-spotted spider mite (TSSM) were determined. Total fecundity on TSSM in the presence of the pollen was significantly higher than those on the pollen alone. The intrinsic rate of increase (r) on TSSM in the presence of the maize pollen (0.1409 day-1) was significantly higher than those on TSSM (as control) and/or the other diets. In addition, N. californicus consumed fewer prey in the presence of the maize pollen than the other pollen types. However, lower prey consumption in the presence of this pollen was compensated by an increase in reproduction and survive. In conclusion, the effectiveness of N. californicus on TSSM in the presence of the maize pollen was superior to the other pollens. However, although the other pollen types had no obvious positive effect on the performance of N. californicus, they might increase long-term persistence of the predator-prey system.

The study of interactions between host plant cultivars and biological control agents is important in integrated pest management programs. In this study, the life table parameters and predation rate of Typhlodromus bagdasarjani Wainstein & Arutunjan were determined on two-spotted spider mites reared on a susceptible (Isfahan) or a resistant (Neishabour) eggplant cultivar. All experiments were carried out under laboratory conditions, at 25 ± 1 °C, 60 ± 5 % RH and a photoperiod of 16:8 (L:D) h. A significant difference was observed between mean developmental time of immature stages of T. bagdasarjani on the two eggplant cultivars: 6.6 versus 7.5 days, on the susceptible and resistant cultivar, respectively. Net reproductive rate (R 0) of T. bagdasarjani did not differ between the cultivars. Doubling time on the susceptible and resistant cultivars was 3.48 versus 5.72 days, mean generation time (T) was 10.13 versus 16.08 days, respectively. Total fecundity was higher on susceptible than on resistant eggplants, the intrinsic rate of population increase (r) was 0.188 versus 0.119 day(-1), respectively. Daily and total prey consumption of various life stages of T. bagdasarjani on two-spotted spider mite reared on susceptible versus resistant eggplant differed; total consumption was higher on spider mites reared on the resistant cultivar. However, the lower intrinsic rate of increase and higher mortality of the predator on the resistant eggplant (Neishabour) revealed that more attention should be devoted to integrated control of spider mites using resistant cultivars and phytoseiid mites.