When to Spray Peach Trees With Insecticide?
- If oriental fruit moth infests your tree and the tips of new shoots begin to wilt, they should be cut off and removed immediately. This will prevent the larvae from emerging and reaching adulthood. You can use an oriental fruit moth trap to determine when to apply insecticide, because it functions through the use of sex pheromones that attract the males. Place the lure in a sticky-bucket trap or cardboard box, and hang in the tree at bloom time. When the collection of moths reaches a peak, wait six days before spraying. For second and third generations of the moth, wait until three days after the peak of collection and spray again.
- If mites are a problem, a three-part plan works best. First, spray a horticultural oil on the green tips in early spring to prevent the mites from overwintering in the tree. Second, diazinon, malathion, or rotenone works on mites but should be applied sparingly, leaving the mites' natural predators to do most of the work. Apply this just as the buds begin to show. Last, use insecticidal soap alone or mixed with the insecticide after the petals fall.
- Peach tree borers are clear-winged moths whose larvae bore under the bark through wounds and cracks in the tree. An application of paradichlorobenzene (PDB) crystals around the base of the tree in the fall works as a good preventive. Do not let it come in contact with the trunk. Sprays containing lindane endosulfan or chlorpyrifos should be used in the first or second week of July. Let the mixture thoroughly wet the trunk and saturate the ground around the trunk. Apply a second coating in late August or early September.
- Peach twig borers are similar to peach tree borers. These are brown moths that overwinter in chimney-shaped cocoons on branches. An application of dormant oil at the first sign of bud break will suffocate the caterpillars before they can emerge. If tips droop after this, some borers have survived. Cut off the tips and dispose of them, or later generations of the caterpillar will bore into the fruit at the stem. Spraying should be done in mid-June using an insecticide containing endosulfan, phosmet, diazinon or methoxychlor.
