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 degrees 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 (r(m)) 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 (lambda) was also significantly (p < 0.05) greater for C. noacki (1.173) than for A. floccosus (1.079). The larger values of r(m) and lambda recorded for C. noacki under experimental conditions indicate that this aphelinid has the potential to decrease populations of A. floccosus.