Aphids

Tiny greenish or reddish bugs that fix themselves to the bottoms of apple, pear, and plum leaves and suck plant juices.  Leaves may curl.  Aphids also produce a sticky honeydew that attracts ants and sometimes forms a black mold.  Woolly apple aphids leave white, cottony puffs along twigs.  Spray with dormant oil in late winter, then follow a regular program of all-purpose spray throughout the season.  For severe infestations, spray with malathion, carbaryl, or diazinon following  direcions on the label.  Encourage or import lacewings, ladybugs, or trichogamma wasps.