Pear trees are a wonderful addition to almost any garden. As with any fruit tree, your pear requires some care to protect it from a variety of problems, including worms,. The most common worm that affects pears is the codling moth larva, which infects both pears as well as apples. The answer to your worm problem in pears is to spray at least once per season, once fruit has set.
Mix the insecticide according to the manufacturer's instructions. Use measuring instruments that are reserved for measuring insecticide and which will not be returned to the kitchen. Wear gloves and eye goggles whenever mixing chemicals.
Load the mixed insecticide into a garden sprayer. The following quantities of spray will be needed for the height and width of your tree: for a tree that is 5 feet high and 5 feet wide you will need 1 gallon of spray; for a tree that's 10 feet by 10 feet you will need 2 gallons of spray; for a tree that's 15 feet by 15 feet you will need 3 gallons of spray and for a tree that's 20 feet by 20 feet you will need 4 gallons of spray.
Choose a windless day approximately two weeks after petal fall, when fruit is just starting to set on the tree. Wear gloves, eye goggles and a breathing mask as you spray all leaves and fruit with your insecticide mixture. Use a ladder if necessary to reach all areas of your tree.
Spray a second time 10 days after the first application. Always spray on a windless day and do not spray if rain is expected within 24 hours.
Continue spraying every 10 days while fruit is growing if codling moths are still present.