Pests -- Aphids

Aphids are usually found on the underside of leaves and stems of plants. They are small usually green insects that are oval, pear or egg shaped. However, aphids can be many colors from light green, yellow, brown to red. They may or may not have wings and are often found in clusters.  All aphids have little tubes that stick out their back end called cornicles. If you have a magnifying lens you may notice that each time they molt, they leave a white case behind. Aphids secrete a waste product called honey dew. This will make leaves shiny or sticky and is a great place for molds to grow that will damage or kill your plants. Older leaves start to curl and young leaves may grow deformed with an infestation. Aphids reproduce at a tremendous rate. They can kill a plant in weeks. They also can help transmit viruses and mold which also can kill your plant. Some aphids reproduce parthenogenetically. This means there are no boys. The girls give birth to other girls that are pregnant with girls etc. This means a single female left behind after you clean the plants can result in thousands of aphids in a few weeks.

Aphids are not too difficult to control if you catch them early. If you see a section of the plant containing aphids galore, snip it off and dispose of it. It doesn’t cure the problem but it will slow the advance. This is true for spider mites and white flies too. Washing the plant with a mixture of one teaspoon dish soap or laundry soap per gallon should wash off the aphids or at least wash off their outer cuticle so that they will then dehydrate. I have read that you can spray your plants with an oil mixture (vegetable oil) this will clog the aphids breathing tubes and kill many of them. I should mention that if you have ants growing in the garden you need to get rid of them because they are “farming’ the aphids and will move them around and help them to survive in your garden. Ants follow a trail of chemicals so you should be able to find their colony and treat it. If they are in your soil you should not use chemical ant sprays since if the chemical is in the growth medium it is in the plants too. If you are not going to eat your plants soon, you could try pyrethrum which is effective on most aphids.

There is of course a non chemical biological solution. Lady bugs and green lacewings are bugs that eat aphids. I have never used the green lace wings but lady bugs are easy to buy and use online. As with the white fly predator wasps the lady bugs will keep the aphids in check but might not control the problem forever. If you can start over after you harvest, you need to sterilize the grow area, sterilize or get new growth medium and start over without aphids.

I have some good informaion that might help under my root aphids post

Good Growing,
Dr. E.R. Myers