Five insecticides, acephate (780 mg/litre), imidacloprid (50, 100 or 150 mg/litre) and three experimental “organic” insecticides, YR55 (1.2 g/litre), YR65 (1 ml/litre) and YR70 (3.6 g/litre) as well as water control were applied three times (7-12 days apart) to pot plants of Asplenium bulbiferum (hen and chicken fern) infested with longtailed mealybugs (Pseudococcus longispinus). After three applications, the water-treated plants had 82% of fronds infested and a mean of 37 mealybugs on the youngest infested frond. The industry standard insecticide, acephate, reduced the mealybug populations to zero, while YR65 and imidacloprid reduced the infestation to 1-4% fronds infested and mean of 0.5-2.5 mealybugs on the youngest infested frond. In these treatments only old fronds were infested. YR55 and YR70 gave poor control and young fronds were infested.