Life table parameters of the predatory mite, Blattisocius mali Oudemans (Mesostigmata: Blattisociidae), fed on eggs and larvae of the stored product mite, Tyrophagus putrescentiae (Schrank)

Background The predatory mite, Blattisocius mali Oudemans (Mesostigmata: Blattisociidae), feeds on various species of storage mites such as Tyrophagous putresentiae (Schrank). In this study, life table parameters and consumption rates of B. mali were determined when fed on the eggs and larvae of T. putrescentiae as the prey under laboratory conditions. Results Based on the age-stage two-sex life table analysis, the total pre-ovipositional period (TPOP) of the predator was considerably lower by feeding on host larvae than that on eggs. Also, mean fecundity (eggs/female) of the B. mali was 2.60-fold higher on host larvae than its eggs. Moreover, the intrinsic rate of increase (r), as the most important parameter was 0.272 and 0.357 day(-1), respectively, by host mite eggs and larvae as food. This showed the significantly greater influence of T. putrescentiae larvae than eggs on mass production of the predatory mite. The same trend was observed in finite rate of increase (lambda), net reproductive rate (R-0), gross reproductive rate. But mean generation times (T) were statistically the same by feeding both host stages. Maximum longevity of male and female individuals was, respectively, 21 and 22 days when eggs were fed. By feeding on larvae as prey, maximum longevity was lowered to 20 days in both predator sexes. However, the net predation rate (C-0) and transformation rate from prey population to predator offspring (Q(P)) were significantly higher by feeding on host eggs (97.420 and 3.049) than its larvae (41.3936 and 0.5575), respectively. Conclusion From practical biocontrol view, both eggs and larvae of T. putrescentiae can be consumed and therefore controlled by the predatory mite, B. mali. From mass production view, larvae of T. putrescentiae produced a better fitness in the predatory mite than its eggs and can be used in augmentation programs of B. mali.