I noticed the other day that my rose bushes have aphids. Aphids, sometimes called plant lice, are very small sap sucking insects. There are many different species of aphids and they come in different sizes.
Aphids may be green, red, brown, black and sometimes a fuzzy white or gray. All plant lice no matter how small, have tiny pear-shaped bodies with long legs and antennae.
Aphids commonly begin to infest rose bushes this time of the year, especially when roses are side dressed with composted manure or are fertilized heavy. High levels of nitrogen encourage aphid reproduction and plant lice tend to do the most damage when temperatures are between 65° – 80°F.
During the hot summer months apples trees can suffer from wooly apple aphids, green apple aphids and rosy apple aphids.
Ants and plant lice are often partners in crime. If you see ants in large numbers crawling up a tree or a bush, you can be pretty sure that aphids are present. In some situations ants will watch over and protect aphids from predators because ants like to feed on the sticky “honeydew” that aphids excrete. Plant lice and ants go together like peas and carrots.
Aphids will not kill a large plant, rose bush or fruit tree, but a heavy infestation can cause leaves to curl, deform flowers and weaken plants.
Aphids do spread plant viruses and young plant seedlings are very susceptible to aphid damage. Cabbage, beets, melons, squashes, pumpkins, potatoes and beans often suffer from aphid transmitted viruses.
A FEW WAYS TO CONTROL APHIDS
Aphids are very easy to control and it seems that every gardener has their own personal favorite aphid remedy. For just a few plants and a light infestation, aphids can be removed by hand or sprayed off the plant/plants with a spray or stream of water from a garden hose. If you are going to control plant lice with a spray of water it is best to do it early in the day so the plants can dry off in the sun and thereby reduce the possibility of fungal diseases.
For more serious infestations especially in fruit trees, aphids can be controlled by means of a chemical control like malathion, permethrin and acephate .
For gardeners who prefer a more natural approach to pest control, soapy water delivered by means of a pressure tank sprayer or a small squirt or spray bottle works well.
For fruit trees I use a ¼ cup of Dawn dish detergent or Murphy Oil Soap in a 3-gallon spray tank of water. I spray only the trunk of the trees and never the leaves or fruit.
But take care and don’t use a soapy water spray on over stressed plants or when temperatures are above 90 F. because you’ll burn the leaves and do more harm than good.
No matter what type of spray you choose, be sure to spray the underside of the plant leaves.That where they tend to hide.
Aphids do have natural enemies and predators and sometimes biological controls can be effective in reducing aphid populations especially in small backyards.
Lady bugs, lace wings and syrphid flies are the best known predators of plant lice. Lady bugs can be ordered by mail and when properly handled can afford some relief to a heavy aphid infestation.