How to Kill Mealybugs
If you're dealing with a small mealybug infestation, soak a cotton swab in 70-percent isopropyl rubbing alcohol and rub it over the surface of the infested plant. If there's a larger infestation, try spraying the plant with a mixture of water, 1 teaspoon of neem oil, and 2-3 drops of dish soap. You may need to resort to ornamental pesticides if the infestation persists.
Dip a cotton swab in 70-percent isopropyl rubbing alcohol. Avoid using other kinds of alcohol or you could damage the plant you're treating. Rub the cotton swab over the surface of the infested plant. Make sure you get underneath the leaves and inside the crevices on the branches. Mealybugs tend to hide in hard-to-reach places, so it's important you completely cover the plant you're treating with the rubbing alcohol. Use a spray bottle to apply rubbing alcohol to large plants. Fill the spray bottle with rubbing alcohol and spray it over the surface of large plants that are infested with mealybugs. Remove any mealybugs you see on the plant. Mealybugs look like small, white bugs with a waxy coating. Pick the mealybugs off with your hand and dispose of them in the trash. Mealybugs don't bite, but you may want to wear gardening gloves so you don't get their waxy coating on your fingers. Repeat weekly until the mealybugs are gone. Since mealybugs are good at hiding in hard to reach places, you'll likely need to do multiple applications of rubbing alcohol before they're all killed. Even if you don't see anymore mealybugs, it's a good idea to do a few more applications just in case there are some lingering bugs. You'll know the mealybugs are gone when you can't see anymore on the plant and the plant remains healthy and green. Mix together water, liquid dish soap, and neem oil in a spray bottle. Use 1 teaspoon (4.9 mL) of neem oil and 2-3 drops of dish soap. Neem oil is a vegetable oil that comes from neem trees that can be used to kill mealybugs. Spray the plant you’re treating until it’s soaked. Make sure you spray underneath the leaves, at the base of the branches, and over the top of the soil the plant is in. You want the mealybugs to be completely smothered with the neem oil mixture. Move the plant to a shaded area to dry. Don't keep the plant in direct sunlight or extreme heat or it could burn. If you're spraying outdoor plants that are rooted in the ground, wait for a shady day when it's below 85 °F (29 °C) out. Spray the plant weekly until the mealybugs are gone. One application of neem oil probably won't kill all the mealybugs on the plant. Because mealybugs have a rapid lifecycle, you'll need to routinely kill the newly-hatched bugs every week until all of the mealybugs have been killed off. If the plant looks healthy and you don't see anymore mealybugs on it, they're most likely gone. Prune off any infested branches before you apply an insecticide. Infested branches will have a waxy, white coating on them. Pruning will help get rid of some of the mealybugs, and it will make the insecticide more effective because there will be fewer places for the mealybugs to take shelter. Use an insecticide that's designed for ornamental plants. Check the label on the insecticide if you're not sure. Avoid using insecticides that aren't made for ornamental plants or you could damage the plant you're treating. Some ornamental insecticides you could use to kill mealybugs are acephate, malathion, carbaryl, and diazinon. Spray the plant with the insecticide until it's soaked. The leaves and branches of the plant should be dripping with insecticide. Make sure you get underneath the leaves and at the base of the branches on the plant. Follow the application instructions that came with your insecticide for the best results. Do regular insecticide applications until the mealybugs are all killed. It may take more than one application to remove all the mealybugs on the plant. Check the instructions that came with your insecticide to see how frequently you can use it without damaging the plant. If the plant is thriving and you can't see anymore mealybugs on it, you've likely killed all of the mealybugs. Inspect new plants for mealybugs before you introduce them to your garden. Look for small, round, wax-covered insects that have a white color. If you find mealybugs on a new plant, pick them off and dispose of them. If there are a lot of mealybugs on the plant, you may need to throw it away or return it to where you bought it from. Never introduce a mealybug-infested plant to your garden or the infestation will spread to your other plants. Check your plants for mealybugs regularly. It's easier to prevent a big mealybug infestation if you routinely eliminate small outbreaks. If you discover mealybugs on one of your plants, pick them off by hand. If the plant if heavily infested, remove it from your garden so the infestation doesn't spread. Throw away garden tools that are infested with mealybugs. Mealybugs can gather on garden tools like shovels, plant clips, and pots. Always check your tools for mealybugs and avoid using them if you find any or the bugs could spread to your other plants. Avoid fertilizing your plants with nitrogen if possible. High levels of nitrogen can cause mealybugs to reproduce faster. If your plants don't need a nitrogen fertilizer, use a non-nitrogen fertilizer instead. 
Dip a cotton swab in 70-percent isopropyl rubbing alcohol. Rub the cotton swab over the surface of the infested plant. Use a spray bottle to apply rubbing alcohol to large plants. Remove any mealybugs you see on the plant. Repeat weekly until the mealybugs are gone. Mix together water, liquid dish soap, and neem oil in a spray bottle. Spray the plant you’re treating until it’s soaked. Move the plant to a shaded area to dry. Spray the plant weekly until the mealybugs are gone. Prune off any infested branches before you apply an insecticide. Use an insecticide that's designed for ornamental plants. Spray the plant with the insecticide until it's soaked. Do regular insecticide applications until the mealybugs are all killed. Inspect new plants for mealybugs before you introduce them to your garden. Check your plants for mealybugs regularly. Throw away garden tools that are infested with mealybugs. Avoid fertilizing your plants with nitrogen if possible. 