|Sri lanka beetles are eating the leaves on my plants. How can I kill the beetles?|
|Sri Lanka weevils are amazingly resistant to most insecticides. The best way to get rid of them is to either hand pick them off your plants, (at night with a flashlight works best because they hide under the leaves during the day) or take out a big dark colored piece of cloth or a small tarp, spread it under the plants then shake the plants vigorously. The weevils will fall down onto it where you can collect them and drop into a cup of soapy water.
You'll probably have to repeat the process several times to get all the generations. New ones will hatch even if you get all the adults that are visible. They lay their eggs in the ground or mulch under the plants they are eating, so if you can break the life cycle by preventing them from dropping down and hiding in the ground, you will win.
I had good success just going out each night for a couple of weeks before bed time with a flashlight, and picking as many as I could see. After that I planted some Knockout roses nearby that became a "sacrificial" plant so whenever any weevils returned, I'd see them immediately and take care of them. They do love rose foliage.