ladybird beetle or ladybug, member of a cosmopolitan beetle beetle, common name for insects of the order Coleoptera, which, with more than 300,000 described species, is the largest of the insect orders. Beetles have chewing mouthparts and well-developed antennae.
..... Click the link for more information. family with over 4,000 species, including 350 species in the United States. Ladybird beetles are mostly under 1-4 in. (6 mm) long and are nearly hemispherical in shape, with very short legs. They are usually red or yellow with black spots, or black with red or yellow spots, the common species differing only in the number of spots. They have a bitter taste, and their bright coloration is thought to serve as a warning to predators. The name is believed to date from the Middle Ages, when these beneficial beetles were dedicated to the Virgin. Nearly all ladybird beetles, both larvae and adults, are predators on destructive, plant-eating insects. The eggs are laid on plants infested with aphids or scale insects, on which the larvae feed until they pupate in the remains of the last larval skin. The adults gather in large numbers in the fall, prior to winter hibernation, and are often collected at that time by farmers for use in pest control. The first outstanding demonstration of pest control by use of natural enemies occurred in the United States in 1889, when Australian ladybird beetles (Rhodolia cardinalis) were imported to wipe out the cottony-cushion scale, an insect that had accidentally been imported from Australia to California and there became a threat to citrus orchards. The Mexican bean beetle (Epilachna varivestis), which has spread through E North America, and the squash beetle (E. borealis) are the only North American ladybird beetles considered destructive. They are yellowish with black spots; adults and larvae feed on plants. Ladybird beetles are classified in the phylum Arthropoda Arthropoda (ärthrŏp`ədə) [Gr.,=jointed feet], largest and most diverse animal phylum.
..... Click the link for more information. , class Insecta, order Coleoptera, family Coccinellidae.

ladybug

or ladybird beetle

Any of the approximately 5,000 widely distributed beetles of the family Coccinellidae. The name originated in the Middle Ages, when the beetle was dedicated to the Virgin Mary and called “beetle of Our Lady.” Ladybugs are hemispheric and are usually 0.3–0.4 in. (8–10 mm) long. They have short legs and are usually brightly coloured with black, yellow, or reddish markings. Several generations are produced each summer. Ladybugs are often used to control such insect pests as aphids, scales, and mites, which they eat. Several species of ladybugs feed on plants.