Life table parameters of the coccinellid Hyperaspis polita, a native predator in Iran, feeding on the invasive mealybug Phenacoccus solenopsis

Abstract

Hyperaspis polita Weise (Coleoptera: Coccinellidae) is one of the most important predators of the cotton mealybug, Phenacoccus solenopsis Tinsley (Sternorrhyncha: Coccoidea: Pseudococcidae), in southern Iran. The development, survivorship, longevity, reproduction, and life table parameters of this predator were evaluated at 25, 30, and 35±1°C, 65±5% RH and a photoperiod of 14L:10D. The duration of total pre-adult stage in males and females decreased from 32.63 and 30.06 at 25°C to 19.96 and 19.37days at 35°C, respectively. The oviposition period of females was significantly affected by temperature that was, 47.73, 68.66 and 27.65days with average egg production of 207.37, 505.50, and 151.03 at 25, 30, and 35°C, respectively. According to the age-stage, two-sex life table, the highest values of the intrinsic rate of increase rm were obtained at 30 (0.112d−1) and 35°C (0.120d−1) with no significant difference. The finite rate of increase (λ) was the highest at 30 (1.130d−1) and 35°C (1.146d−1) with no significant difference. The net reproductive rate was the highest at 30°C (R0=204.240 offspring) and the mean generation time was shortest at 35°C (T=29.87d). The results indicate that suitable temperature for population development and fecundity of H. polita is around 30°C, which could be a result of adaptation of this coccinellid predator to the warm climate of southwestern Iran.