Temperature-dependent functional response of Aenasius bambawalei (Hymenoptera: Encyrtidae) to different population densities of the cotton mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae)

The functional response of Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) to different population densities of Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) was investigated under laboratory conditions of 65 ± 5% R.H., a photoperiod of 14L : 10D and at temperatures of 25, 30 and 35 ± 1°C. Two, 4, 6, 8, 16, 32 and 64 third instar nymphs of P solenopsis were exposed to newly emerged mated female parasitoids for 24 h. The parasitoid exhibited a type II functional response at all temperatures. The searching effi ciencies (a) and handling times (Th) were 0.1818 h-1 and 5.0012 h at 25°C, 0.1382 h-1 and 3.2807 h at 30°C, and 0.2097 h-1 and 2.3635 h at 35°C, respectively. The maximum attack rates (T/Th) were 4.8, 7.3 and 10.2 nymphs at 25, 30 and 35°C, respectively. This indicates that A. bambawalei is more likely to be an effective biological control agent of P. solenopsis in warm seasons.