Q: Something is eating up many leaves on my bougainvilleas, hibiscus, roses and some other plants. I have found some very small green worms on some leaves plus small white hard shell bugs.They are oblong in shape and the size of a pencil eraser and have a very hard shell. I have tried different store bug sprays and also made my own spray with Hot Sauce, soap, etc. Nothing has helped. Can you help me? Also, my hibiscus flowers have been falling off too easily, most of them as buds. I noticed this way before the bug problem. I have tried different food for hibiscus but that has not helped either. I need help badly, before I give up gardening. Mrs. Claudette Michael Margate, Florida
A: I think you have several different insect pests at work.The "white hard shell bug" sounds like a scale. This insect builds a shell over itself and sucks plant juices. Ordinary contact pesticides can't reach it and are ineffective. You need to use an oil spray that smothers it, such as Vegol Year-Round Pesticidal Oil. This organic product is made from canola oil.
Any number of insects could be chewing your plants, including caterpillars. For them, apply a combination rotenone-pyrethrin spray, which is made from chemicals found in plants. You can find both products I mentioned at www.planetnatural.com.
I'm not sure why the flower buds of your hibiscus keep dropping, but this often happens when the plant gets too dry in the summer. If the plant wilts badly, the buds turn yellow and fall.