Assessing compatibility of Hippodamia variegata and resistant rose cultivar in the management of Macrosiphum rosae

Integrated management with emphasis on combination of biocontrol agents and resistant varieties can be one of the efficient strategies to manage the pests. In this study, the effect of susceptible ('Orange') and resistant ('Tea') rose cultivars on demographic parameters of the rose aphid, Macrosiphum rosae (L.) (Hem.: Aphididae), and its predatory lady beetle Hippodamia variegata (Goeze) (Col.: Coccinellidae) was determined under laboratory conditions. The obtained data were analysed according to the age-stage, two-sex life table theory, the means, as well as the standard errors of all parameters, were estimated by the bootstrap procedure. Mean developmental time of immature stages (nymphal period) of the aphid on the resistant cultivar (15.20 days) was significantly higher than the susceptible one (9.53 days). The intrinsic rate of increase (r) of the rose aphid on the susceptible and resistant cultivars was 0.330 and 0.115 day-1, respectively. Furthermore, the values of the intrinsic rate of increase (r) of the predator fed on the aphids reared on the susceptible and resistant cultivars was 0.145 versus 0.126 day-1, respectively. The total pre-oviposition period (TPOP) of the lady beetle on the resistant cultivar (26.66 days) was significantly longer than that on the susceptible one (23.83 days), but total fecundity on the resistant cultivar (370.34 eggs/female) was significantly lower than that on the susceptible cultivar (451.65 eggs/female). According to obtained results, considering the lower intrinsic rate of increase (r) and fecundity of the predator on the resistant rose cultivar ('Tea'), more attention should be devoted for integrated control of rose aphids using resistant cultivars and predatory lady beetles.