![]() ![]() Ladybugs are generally considered useful insects as many species feed on aphids or scale insects, which are pests in gardens, agricultural fields, orchards, and similar places. Some species (e.g., Hippodamia convergens) gather into groups and move to higher land, such as a mountain, to enter diapause. As in many insects, ladybirds in temperate regions enter diapause during the winter. They also form large aggregations when they go into hibernation in winter (Honek et al. Some species are migratory and form large aggregations during the migratory period. The ratio of infertile to fertile eggs increases with scarcity of food at the time of egg laying (Perry and Roitberg 2005). These appear to provide a backup food source for the larvae when they hatch. Most ladybird species are univoltine, producing only one generation a year, although some are bivoltine.Ĭoccinellids lay extra infertile eggs with the fertile eggs. The entire life cycle of the Coccinellid is only for to seven weeks. This state lasts 10–15 days, and they then go into a pupal stage before becoming an adult coccinellid. In most species, these eggs hatch into a larval state within a week. Most coccinellids mate in spring or summer and the female lays a cluster of eggs (numbering from a few to a few hundred, depending on species) as near as possible to an aphid colony. Insects that undergo holometabolism pass through a larval stage, then enter an inactive state called pupa, and finally emerge as adults (imago). Complete metamorphosis, also called holometabolism and complex metamorphosis, is a term applied to those processes in which the larvae differ markedly from the adults. Ladybugs are endopterygotes-a superorder of insects of the subclass Pterygota that go through distinctive larval, pupal, and adult stages, or complete metamorphosis. The family name comes from its type genus, Coccinella. Since aphids and scale insects occur nearly everywhere in the world, ladybirds are also cosmopolitan. Ladybirds are usually found where aphids or scale insects are, and they lay their eggs near their prey to increase the likelihood the larvae will find the prey easily. While they are often used as biological control agents, introduced species of ladybugs (such as Harmonia axyridis or Coccinella septempunctata in North America) can outcompete and displace native coccinellids, and become pests in their own right. They are also known to eat certain plants and crops when no other food is present, making them a possible pest to farmers and gardeners. This becomes quite obvious when one handles a coccinellid roughly.Ĭoccinellids are typically predators on Hemiptera, such as aphids and scale insects, though members of the subfamily Epilachninae are herbivores, and can be very destructive agricultural pests (e.g., the Mexican bean beetle). Adult coccinellids are able to reflex-bleed hemolymph from their leg joints, releasing their oily yellow toxin with a strong repellent smell. However, a human would have to eat several hundred coccinellids before feeling any effects. In fact, most coccinellids are indeed poisonous to smaller predators, such as lizards and small birds. This defense works because most predators associate bright colors (especially orange and black or yellow and black) with poison and other unpleasant properties. It is believed that coccinellids are often brightly colored to ward away potential predators. ![]() (Conversely, there are many small beetles that are easily mistaken as ladybugs, such as tortoise beetles). ![]() A very large number of species are mostly or entirely black, gray, or brown, however, and may be difficult for non-entomologists to recognize as coccinellids. They are commonly yellow, orange, or scarlet with small black spots on their wing covers, with black legs, head and antennae. They have short legs and are nearly hemispheric dorsally. The elytra are not used in flying, but generally must be raised in order to move the hind wings.Ĭoccinellids are small insects, ranging from one to ten millimeters (0.04 to 0.4 inches). As beetles (order Coleoptera), they are characterized by a particularly hard exoskeleton, and the hard wing-cases (elytra) that tend to cover the hind part of the body and protect the second wings, the alae. As insects (Class Insecta), they have three pairs of jointed legs an abdomen that is divided into 11 segments and lacks any legs or wings ectognathous or exposed mouthparts, and a body separated into three parts (head, thorax, and abdomen), with one pair of antennae on the head. As arthropods (Phylum Arthropoda), ladybugs have jointed appendages, an exoskeleton (hard, external covering), segmented body, ventral nervous system, digestive system, and open circulatory system. ![]()
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