The most valuable beetle to humans is the ladybug. There are over 350 species of ladybugs in North America. Ladybugs are red or orange with black spots or irregular marks. Some are even solid black or black with red spot. Their shiny bodies are dome shaped, oval, or convex. Ladybugs have short legs and short antennae. Their body size ranges from 1/16 inch to 3/8 inch long. Ladybugs have two pairs of wings, but only the rear pair is used for flying. The fore wings are usually hard and when closed form a protective covering for the more fragile rear wings. In flight these hard wings are used for balance.
Ladybugs live in trees, shrubs, fields, beaches, and in homes. In the fall they crawl to winter sites. A few to several hundred gather for the winter. The winter gathering spot may be at the base of a tree, along a fence row, under a fallen tree, or under a rock. In the mountains large numbers of up to 500 gallons of beetles may move in together for the winter..
Ladybugs eat many different soft bodied insects with aphids being their main food. An adult female may eat 75 aphids in a day. The smaller male may eat up to 40 aphids in a day. One larva may eat up to 350 aphids during its life span. More than 5,000 aphids may be eaten by a single adult in its lifetime.
Ladybugs have a complete metamorphosis cycle: egg, larval, pupal, and adult. The female lays the eggs. They are tiny light yellow eggs. Each mass has up to 12 eggs in it. These masses can be found under leaves. The eggs hatch in about a week. In a month they pupate. The pupal period lasts for one week. Then the adult comes out.