تاثیر ده نسل تغذیه از گرده زعفران بر کارآیی کنه شکارگر Neoseiulus californicus (Acari: Phytoseiidae)

Generalist predatory mites of the family Phytoseiidae are important biocontrol agents of mites, thrips, whiteflies and other small insects in different crops, which need to be mass reared for augmentative biological control programs. Although alternative diets may facilitate their cost-effective rearing, the quality of an alternative diet such as pollen grains is critical for the mass rearing of natural enemies and influences on the efficiency and quality of natural enemy products. Since, the effects of long-term feeding on pollen grains on the predator performance needs to be evaluated, the performance of Neoseiulus californicus (McGregor) as a generalist biocontrol agent of spider mites was evaluated up to 10 generations (G1 and G10) fed on the saffron pollen. All experiments were conducted under laboratory conditions at 25±1°C, 60±5% RH, and a photoperiod of 16:8 (L: D) h. The developmental time and total pre-oviposition period (TPOP) had no significant difference between the first and 10th generations tested. The values of the total life span, oviposition days, and fecundity of the reared individuals on saffron pollen in G1 were significantly higher than those in G10. Furthermore, the intrinsic rate of increase (r) of N. californicus was 0.163 day-1 when fed at the first generation which was significantly higher than that in 10th generation (0.037 day-1). The values of the net reproductive rate (R0) in G1 (22 eggs/individual/generation) were significantly higher than that in G10 (2 eggs/individual/generation). Based on the results, the saffron pollen could not be considered as a suitable diet for long-term rearing of N. californicus, because feeding on this diet had adverse effects on the predator’s performance. Totally, spraying the saffron pollen on greenhouse plants, or using it as a banker plant for maintenance of the population of the predator in the absence of the prey is recommended.