Let's look this week at a few of the more common pests that we are encountering. There are many, many out there. But please keep in mind that at least 90% of the insects we have are BENEFICIAL and we should not take aggressive action against all of them.
1. Flea Beetles-Are your potatoes showing signs of an insect eating holes in the leaves? Mine are! This is a sign of flea beetles, which cause tiny, but numerous, holes in the leaves of some of the common vegetable plants: broccoli, eggplant, beets, peppers, radishes, spinach and, yes, even tomatoes. How are we to control these pests when they are attacking our food crops? The best soultion is pyrethrum, an organic liquid that comes in a concentrate. Add water (read the label carefully) and spray the plants, especially the underside of the leaves. You can also use Neem or a hot pepper spray. They all will wash off in the rain so you will need to repeat your treatment.
2.Another pest that emerges with the warm weather is whitefly. This pest will attack most fruits and vegetables. They are cleary visible, though very tiny, on the leaves, usually on the underside. They can severely weaken the plant and cause the leaves to die off. You will often find a shiny, sticky honeydew which is seceted by the whitefly. The best organic treatment is insecticidal soap. This very common insect treatment is available at most garden centers and comes in a pump spray. It is very easy to use. Again be sure to spray the UNDERSIDE of the leaves and repeat spraying after it rains. Repeat spraying every 3 days or so for 2 weeks.
3. Are the leaves of your deciduous trees (those that produce new leaves each year) showing shot holes? Usually this is a sign of winter moth. Unfortunately there is little to be done at this time of the year. The winter moth infestation has been followed southward from Nova Scotia over the years and it arrived in Rhode Island a couple of years ago. Sometimes you will see the larvae stage of the winter moth-a little green worm hanging from a string on the tree. The best treatment for this pest is a dormant oil spray in early spring. You'll need a temperatre of 45 degrees to spray. Dormant oil use in the later spring or summer will not help. Winter moth larvae eat into leaf buds just before they open and feed on the leaves. The leaves then emerge with many holes. Winter moth will not kill a tree in one season but if the infestation continues for, say, four years, it could cause the mortality of the tree.
These are a few of the common pests around. Needless to say we'll have more to talk about others in future blogs.
For the answer to any gardening question, visit the URI Master Gardener Kiosk at Paradise Park (Paradise & Prospect Avenues) in Middletown every Sunday, noon till 2 pm. We will do our best to provide you with useful answers to your questions regarding pests, weeds, perennials, lawns, trees and vegetables. For further information contact us at firstname.lastname@example.org.