Life table parameters of the woolly whitefly Aleurothrixus floccosus (Hemiptera: Aleyrodidae) and its parasitoid Cales noacki (Hymenoptera: Aphelinidae)

Abstract

Biological parameters of the woolly whitefly Aleurothrixus floccosus (Hemiptera: Aleyrodidae) and its parasitoid Cales noacki (Hymenoptera: Aphelinidae) were determined at 25.0 ± 2.0°C, 50.0 ± 10.0% RH and a photoperiod of 14L : 10D on three different Citrus host plants. The percentage survival of A. floccosus ranged between 40.23 and 44.44%. The highest mortality was recorded in the first nymphal instar with mortalities ranging between 36.36 and 39.39%. On C. aurantifolia the total development time was 39.83 ± 0.68 days and the pre-oviposition, oviposition and post-oviposition periods 2.45, 10.68 and 1.68 days, respectively. Adult longevity was 15.0 days and average fecundity 73.27 ± 9.07 eggs. For C. noacki the pre-oviposition period was 0.8 days, oviposition period 4.38 days and post-oviposition period < 1 day. Adult longevity of C. noacki was 5.18 days and average fecundity 31.25 ± 2.87 eggs. The intrinsic growth rate (rm ) of C. noacki (0.160) was significantly greater ( p < 0.05) than that of A. floccosus (0.076). The value of the finite rate of growth (λ) was also significantly ( p < 0.05) greater for C. noacki (1.173) than for A. floccosus (1.079). The larger values of rm and λ recorded for C. noacki under experimental conditions indicate that this aphelinid has the potential to decrease populations of A. floccosus.

Keywords

• hymenoptera
• aphelinidae
• cales noacki
• parasitism
• life table
• biological control
• woolly whitefly
• population ecology