3.  Lacewings
Lacewings are beneficial insects that belong to a group called nerve-winged insects. The adults are up to ¾ inch long, have long antennae, and transparent green or brown lacy wings held over the body in a rooflike position. The green species has iridescent red-gold eyes and, in its adult form, is one of the most beautiful insects. The larvae are small (up to ½ inch), flat, spindle-shaped insects resembling miniature alligators. They are yellow to gray with reddish brown markings and sickle-shaped jaws for capturing their prey. The larvae suck the body fluids from aphids, mealybugs, scales, and other small insects. Some species carry the remains of their victims on their backs. The larvae are such voracious eaters that they are commonly called aphid lions. The female green lacewings lay their eggs singly on top of a delicate, hairlike stalk projecting from the surface of a leaf or twig. This prevents the hatching larvae from devouring other unhatched eggs. At night, the adult lacewings are attracted to bright lights, and may cling to screen doors. Green lacewings can be purchased from insectaries, companies that raise insect predators and parasites. Because they don't survive the winter well, they should be reintroduced each spring.