Apple trees are frequently infested by a large number of insect larvae that bore into the fruit and feed until they are ready to mature into adults. You can prevent these larval worms from damaging your apple crop by applying a spray pesticide to your apple tree. Several types of insecticides are safe and effective to use on apple trees to prevent worms from ruining your apples.
Insecticide sprays for preventing worms generally contain a number of different chemicals that also treat fungal problems and mites, according to the University of Arkansas. Common ingredients include the insecticides malathion, sevin and sulphur. The dosage and volume of spray for your apple trees varies greatly based on the concentration of each component in the spray. Always read and follow directions as labelled for best results.
Proper timing is an integral part of applying pesticide sprays on apple trees. For best results, apply a pesticide before the insect begins to reproduce during the growing season to prevent the larval worms from attacking apples. Pesticide sprays often need to be reapplied periodically; follow label directions carefully.
Proper care and sanitation practices that maintain the vigour of your apple tree will help prevent worms from becoming a serious problem. Healthy apple trees are less prone to insect infestations than sickly trees. Maintain a regular fertiliser regimen and water your apple trees as needed to maintain soil moisture and promote healthy growth through the growing season. Remove any apples that prematurely fall to the ground in summer. Fallen apples are a perfect place for worms to develop and mature into adult insects that can then spawn more worms to infest your apple tree, according to Utah State University.
Worms vary greatly in size, colour and longevity based on species. Apple maggots, also known as the railroad worm, are small, legless larvae that tunnel through apples leaving brown tracks that ruin the fruit. Infested apples usually fall to the ground and appear shrivelled. The codling moth is a serious worm pest of apple trees and can have two to three generations in a single season, according to Colorado State University. Insecticide sprays, applied regularly, help prevent apple maggots and codling moths from penetrating apple fruits and reproducing on your property.