Bulbs Flower Basics Flower Beds & Specialty Gardens Flower Garden Garden Furniture Garden Gnomes Garden Seeds Garden Sheds Garden Statues Garden Tools & Supplies Gardening Basics Green & Organic Groundcovers & Vines Growing Annuals Growing Basil Growing Beans Growing Berries Growing Blueberries Growing Cactus Growing Corn Growing Cotton Growing Edibles Growing Flowers Growing Garlic Growing Grapes Growing Grass Growing Herbs Growing Jasmine Growing Mint Growing Mushrooms Orchids Growing Peanuts Growing Perennials Growing Plants Growing Rosemary Growing Roses Growing Strawberries Growing Sunflowers Growing Thyme Growing Tomatoes Growing Tulips Growing Vegetables Herb Basics Herb Garden Indoor Growing Landscaping Basics Landscaping Patios Landscaping Plants Landscaping Shrubs Landscaping Trees Landscaping Walks & Pathways Lawn Basics Lawn Maintenance Lawn Mowers Lawn Ornaments Lawn Planting Lawn Tools Outdoor Growing Overall Landscape Planning Pests, Weeds & Problems Plant Basics Rock Garden Rose Garden Shrubs Soil Specialty Gardens Trees Vegetable Garden Yard Maintenance

Fruit Trees & Ants

Fruit Trees & Ants

Fruit Trees & Ants. Seeing a long trail of ants going up the trunk of your fruit tree and congregating on a particular branch can cause you to run for the ant spray, but, according to the University of California at Davis, the ants themselves do not damage fruit trees. It is the tiny aphids they are tending that cause the leaves to curl up and...

Seeing a long trail of ants going up the trunk of your fruit tree and congregating on a particular branch can cause you to run for the ant spray, but, according to the University of California at Davis, the ants themselves do not damage fruit trees. It is the tiny aphids they are tending that cause the leaves to curl up and turn brown, so you must manage both pests to prevent damage to your fruit trees. You are most likely to notice an infestation in early summer, when new shoot growth is at its height.
Identification
Aphids are 2 mm in size, and have soft, pear-shaped bodies; they may be green, brown, black, yellow or red. Aphids are not host-specific, so the same species may attack your cherry, plum and apple trees. They suck liquids from the underside of the leaves, usually the young, tender shoot tips. Other indicators of aphids, besides the ants, are curling leaves, stunted shoot growth, and a sticky substance on the leaves.
Ant-Aphid Relationship
The University of Washington Botanical Gardens explains that ants and aphids have a symbiotic relationship. Aphids digest leaf juices and excrete this sweet, sticky substance called honeydew, which then attracts the ants who eat it. Ants "milk" the aphids to have them excrete the honeydew, and they "tend" the aphids by protecting them from natural predators, including ladybugs, lacewings and wasps.
Possible Damage
Feeding damage to mature trees is usually minor and self-limiting, but young trees may be overcome if the infestation is extensive since defoliation can occur. Once the leaves are curled, they do not recover after pests are controlled, so it is important to identify the problem early. Aphids can carry diseases from one tree to another. The honeydew itself may cause black sooty mold to develop, which reduces photosynthesis in the leaves, and both can reduce fruit quality.
Prevention
Prevention begins in late winter with the use of dormant oil sprays, which smother the overwintering aphid eggs. You should follow the product directions exactly for the desired results. Using dormant oil spray when the tree is not dormant can cause extensive damage to the tree. Use a lower nitrogen or slow-release nitrogen fertilizer to slow shoot growth that attracts aphids in the spring.
Managing Aphids
You will have the best results from managing both the aphid and ant populations. For aphids on small young trees or localized infestations, wipe them off by hand or prune off the shoot tips where they are congregating. On larger trees, wash off aphids with water sprayed from the hose. Spraying the affected trees with insecticidal soap is the least-toxic way to kill aphids, but its effect is temporary and may need to be repeated every few days.
Managing Ants
To keep ants off trees, band them with heavy paper or tree paper, 2 to 3 inches wide, and paint it with Tanglefoot, or other similar product that is sticky, to trap the ants. Do not paint it directly onto the bark, as this will damage the tree. Check the paper every week or so and replace it when it becomes so covered with ants and debris that other ants can walk across the trap. You may use ant bait stations near the bases of trees to kill the entire ant colony.

Check out these related posts