fruit trees, roses, winter vegetables and other landscape plants. They love
cool nights but warm day time temperatures for feeding and breeding. Their
feeding causes new leaves to curl on the edges and glistening, sugary sap on
leaves.
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| Shininess from aphid honeydew dropping on the leaves |
Opening these
curls with your fingers, you will see adults and “babies”. The mother aphid survived
the winter on this plant just below the soil or on neighboring weeds, then
migrated to the new growth when it appeared. Mother aphids don’t need a mate.
They can have babies on their own.
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| Plum leaf curl due to aphid feeding on the inside of the curl |
If protected
inside leaf curls then they are difficult to control without chemicals applied
to the soil and transported to the leaves from the roots called systemic
insecticides. Personally, I would not apply these types of chemicals to plants
that provide food such as vegetables or fruit trees. They are fine if used on
ornamentals like roses, shrubs and trees.
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| Insects overwinter on weeds. Get rid of the weeds and keep a clean garden! |
Other “organic”
options are to make repeat, weekly applications of soap and water sprays or use
oils. Neem oil is safe to use on all vegetables or fruit trees now if they are
not flowering. Or apply dormant oil used during the winter on fruit trees and
ornamentals.
Dormant oils are
okay to use until the weather gets hot. Never apply soap and water, oils or any
insecticide when plants have flowers. Wait until the flowers have passed and
then apply them to protect honeybees.
Some ants pick up
aphids and distribute them to tender, new leaves for feeding. They are the
cattle ranchers of the insect world. You will see the entrance to ant nests being
created now in dry soils near to where aphids are feeding. These are 4 to 6-inch
diameter mounds with a hole in the center.
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| Aphids and ants on apricot leaves. They work together! |
If you find an
entrance to an ant nest you will probably find aphids feeding in nearby plants.
Ants love the sugary “sap” that comes from the aphids. So do bees. Ants protect
aphids if they are threatened and may even transport them to safety.
Controlling in nests helps control
aphids. My favorite method for controlling ants is to lightly sprinkle a poisonous
bait they take back to their underground nest. Products like Amdro work within
24 hours when applied to the entrance of a nest provided the entrance is dry
when it is applied. Read the label of any pesticide before applying it.