Although healthy trees can add to the value of your home, a tree with unhealthy leaves can detract from your property. One popular ornamental and fruit tree variety planted in many homes is the pear tree. Pears produce fruit that can be made into desserts, jam and jelly, while Bradford and other ornamental trees produce beautiful flowers and foliage. Diagnose the symptoms to troubleshoot diseases that plague these trees.
Inspect the leaves of a sickly pear tree closely. Often leaves are plagued by insects or diseases that cannot be seen by the naked eye. The only clue that these insects are affecting your pear tree is in the appearance of the leaves. Leaves that suddenly wilt, shrivel and turn black are a sign of fire blight. Leaves that develop red spots are a sign of the entomosporium bacteria. Purplish-black lesions on the leaves and fruit are a sign of fabraea leaf spot.
Inspect the tips of tree branches. Trees that suddenly lose their leaves or fail to produce leaves are a sign of tree dieback. Tree branches that suddenly bend in a shepherd's crook shape are a sign of fire blight. Fabraea leaf spot will also cause a tree to lose leaves during midsummer.
Place cuttings from your tree in a 1-gallon freezer bag. Transport the cutting to your local county extension office. Most land grant colleges with agricultural programs operate extension offices as a service of their community and continuing education program. An agent with the extension service may know what diseases and pests are affecting pear trees.