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Abstract
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Compatibility of pesticides and biological control agents is the main
concern of Integrated Pest Management (IPM) programs. The present study focused
on the side effects of spirotetramat and chlorpyrifos on the demographic parameters of
Aenasius bambawalei Hayat (Hym: Encyrtidae). Adult parasitoids were exposed to one
ppm of chlorpyrifos and 7.5 ppm of spirotetramat for 24 hours. Then, they were released
on the third instar nymphs of the mealybug Phenacoccus solenopsis Tinsley (Hem.
Pseudococcidae) and their demography was investigated. The results showed that
oviposition period, fecundity, and female and male longevities adversely were affected
by both insecticides. However, the adult pre-oviposition period (APOP), the total preoviposition period (TPOP), and the number of daily eggs of insect females were not
affected significantly. The intrinsic rate of increase (r) was calculated to be 0.16, 0.13,
and 0.12 day-1
for control, spirotetramat, and chlorpyrifos treatments, respectively. The
results of this study revealed that chlorpyrifos at sublethal concentrations have more
negative effects on A. bamabawalei than spirotetramat and need to be applied with
caution in IPM programs.
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