Twenty-five eggs of A. albopictus were exposed to concentrations ranging from 1 to 100 lg/ml of FE, HT and NC. The eggs were put into beakers containing the test solution (100 ml) of each above-mentioned concentration in triplicates. Tap water (100 ml)mixed with acetone (1 ml) served as control. The difference between the hatched and unhatched eggs was examined under a stereomicroscope (20_) and percent egg hatchability was calculated by dividing the number of larvae that emerged from the eggs,
24 h after treatment. Data were subjected to probit analysis software SYSTAT for enumerating effective concentration of the sample to inhibit egg viability (EC50 and EC90).