Expert: Nick McCann Date: 6/30/2008 Subject: Ruby Red
Question I have a Ruby Red grape fruit tree. It is about 15' tall and wide. The last two years it has gotten these little white bugs that leave black looking stuff on the leaves and fruit. It is also dropping some of it's fruit. I have sprayed a wax solution on the leaves but it doesn't bother them. It was in my back yard when I bought our house three years ago and our first crop was perfect. I do not water or fertilize it. I live near the beach in sandy soil in Biloxi, Mississippi. Thanks, Doug
Answer when small insects suck the juices of plants (your Grapefruit for instance) they secrete a sticky, sap like substance that is actually like a honeydew and it attracts an innocuous fungus called sooty mold; this sooty mold is harmless to the the plant and is feeding off the secretions from the insects. Go to Home Depot and purchase a "Horticultural Oil" follow the directions and spray it on during the evening (when the sun is down, because it is oil based) so it doesn't attract the heat from the sun; let it work over night killing the insects and loosening the sooty mold, the next morning, before that days heat from the sun materializes, wash it all off (dead insects and residual oil) with your hose. You may have to repeat that evening again. This will also loosen the mold, so after a few washes, it too will be gone. Nick
