Beetles are a group of insects that form the order Coleoptera, in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, distinguishing them from most other insects; the Coleoptera, with about 400,000 species, is the largest of all orders, constituting 40% of described insects and 25% of all known animal life-forms. The largest of all families, the Curculionidae with some 70,000 member species, belongs to this order. Found in every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles feed on plants and fungi, break down animal and plant debris, eat other invertebrates; some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae eat aphids, scale insects and other plant-sucking insects that damage crops. Beetles have a hard exoskeleton including the elytra, though some such as the rove beetles have short elytra while blister beetles have softer elytra; the general anatomy of a beetle is quite uniform and typical of insects, although there are several examples of novelty, such as adaptations in water beetles which trap air bubbles under the elytra for use while diving.
Beetles are endopterygotes, which means that they undergo complete metamorphosis, with a series of conspicuous and abrupt changes in body structure between hatching and becoming adult after a immobile pupal stage. Some, such as stag beetles, have a marked sexual dimorphism, the males possessing enormously enlarged mandibles which they use to fight other males. Many beetles are aposematic, with bright colours and patterns warning of their toxicity, while others are harmless Batesian mimics of such insects. Many beetles, including those that live in sandy places, have effective camouflage. Beetles are prominent in human culture, from the sacred scarabs of ancient Egypt to beetlewing art and use as pets or fighting insects for entertainment and gambling. Many beetle groups are brightly and attractively coloured making them objects of collection and decorative displays. Over 300 species are used as food as larvae. However, the major impact of beetles on human life is as agricultural and horticultural pests.
Serious pests include the boll weevil of cotton, the Colorado potato beetle, the coconut hispine beetle, the mountain pine beetle. Most beetles, however, do not cause economic damage and many, such as the lady beetles and dung beetles are beneficial by helping to control insect pests; the name of the taxonomic order, comes from the Greek koleopteros, given to the group by Aristotle for their elytra, hardened shield-like forewings, from koleos and pteron, wing. The English name beetle comes from the Old English word bitela, little biter, related to bītan, leading to Middle English betylle. Another Old English name for beetle is ċeafor, used in names such as cockchafer, from the Proto-Germanic *kebrô. Beetles are by far the largest order of insects: the 400,000 species make up about 40% of all insect species so far described, about 25% of all animals. A 2015 study provided four independent estimates of the total number of beetle species, giving a mean estimate of some 1.5 million with a "surprisingly narrow range" spanning all four estimates from a minimum of 0.9 to a maximum of 2.1 million beetle species.
The four estimates made use of host-specificity relationships, ratios with other taxa, plant:beetle ratios, extrapolations based on body size by year of description. Beetles are found in nearly all habitats, including freshwater and coastal habitats, wherever vegetative foliage is found, from trees and their bark to flowers and underground near roots - inside plants in galls, in every plant tissue, including dead or decaying ones; the heaviest beetle, indeed the heaviest insect stage, is the larva of the goliath beetle, Goliathus goliatus, which can attain a mass of at least 115 g and a length of 11.5 cm. Adult male goliath beetles are the heaviest beetle in its adult stage, weighing 70–100 g and measuring up to 11 cm. Adult elephant beetles, Megasoma elephas and Megasoma actaeon reach 50 g and 10 cm; the longest beetle is the Hercules beetle Dynastes hercules, with a maximum overall length of at least 16.7 cm including the long pronotal horn. The smallest recorded beetle and the smallest free-living insect, is the featherwing beetle Scydosella musawasensis which may measure as little as 325 µm in length.
The oldest known fossil insect that unequivocally resembles a Coleopteran is from the Lower Permian Period about 270 million years ago, though these members of the family Tshekardocoleidae have 13-segmented antennae, elytra with more developed venation and more irregular longitudinal ribbing, abdomen and ovipositor extending beyond the apex of the elytra. In the Permian–Triassic extinction event at the end of the Permian, some 30% of all insect species became extinct, so the fossil record of insects only includes beetles from the Lower Triassic 220 mya. Around this time, during the Late Triassic, fungus-feeding species such as Cupedidae appear in the fossil record. In the stages of the Upper Triassic, alga-feeding insects such as Triaplidae and Hydrophilidae begin to appear, alongside predatory water beetles; the first weevils, including the Obrienidae, appear alongside the first rove beetles, which resemb
The rice weevil is a stored product pest which attacks several crops, including wheat and maize. The adults are around 2 mm long with a long snout; the body color appears to be brown/black, but on close examination, four orange/red spots are arranged in a cross on the wing covers. It is confused with the similar looking maize weevil, but there are several distinguishing features: Adult rice weevils are able to fly, can live for up to two years. Females lay up to 300 over their lifetime; the female uses strong mandibles to chew a hole into a grain kernel after which she deposits a single egg within the hole, sealing it with secretions from her ovipositor. The larva develops within the grain, it pupates within the grain kernel and emerges 2–4 days after eclosion. Male S. orzyae produce an aggregation pheromone to which females are drawn. A synthetic version is available which attracts maize weevils and grain weevils. Females produce a pheromone. Control of weevils involves locating and removing all infected food sources.
Rice weevils in all stages of development can be killed by freezing infected food below 0 °F for a period of three days, or heating to 60 °C for a period of 15 minutes. Granary weevil Maize weevil
Pierre André Latreille
Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, only regained his freedom after recognising a rare beetle species he found in the prison, Necrobia ruficollis, he published his first important work in 1796, was employed by the Muséum National d'Histoire Naturelle. His foresighted work on arthropod systematics and taxonomy gained him respect and accolades, including being asked to write the volume on arthropods for George Cuvier's monumental work, Le Règne Animal, the only part not by Cuvier himself. Latreille was considered the foremost entomologist of his time, was described by one of his pupils as "the prince of entomologists". Pierre André Latreille was born on 29 November 1762 in the town of Brive in the province of Limousin, as the illegitimate child of Jean Joseph Sahuguet d'Amarzit, général baron d'Espagnac, who never recognzed him, an unknown mother, who abandoned him at birth.
Latreille orphaned from his earliest age, but had influential protectors – first a physician a merchant from Brive, a baron and his family, who brought him to Paris in 1778. He studied in Brive and in Paris at the Collège du Cardinal-Lemoine attached to the University of Paris to become a priest, he entered the Grand Séminaire of Limoges in 1780, left as a deacon in 1786. Despite being qualified to preach, Latreille wrote that he had never carried out his functions as a minister, although for a few years he signed the letters he wrote "l'Abbé Latreille" or "Latreille, Prêtre". During his studies, Latreille had taken on an interest in natural history, visiting the Jardin du Roi planted by Georges-Louis Leclerc, Comte de Buffon, catching insects around Paris, he received lessons on botany from René Just Haüy, which brought him in contact with Jean-Baptiste Lamarck. After the fall of the Ancien Régime and the start of the French Revolution, the Civil Constitution of the Clergy was declared in 1790, which required priests to swear an oath of allegiance to the state.
Latreille was therefore imprisoned in November 1793 under threat of execution. When the prison's doctor inspected the prisoners, he was surprised to find Latreille scrutinising a beetle on the dungeon floor; when Latreille explained that it was a rare insect, the physician was impressed, sent the insect to a 15-year-old local naturalist, Jean Baptiste Bory de Saint-Vincent. Bory de St.-Vincent knew Latreille's work, managed to obtain the release of Latreille and one of his cell-mates. All the other inmates were dead within one month; the beetle had been described by Johan Christian Fabricius in 1775, but recognising it had saved Latreille's life. Thereafter, Latreille lived as a teacher and corresponded with various entomologists, including Fabricius. In 1796, with Fabricius' encouragement, Latreille published his Précis des caractères génériques des insectes at his own expense, he was placed under house arrest in 1797, his books were confiscated, but the influence of Georges Cuvier, Bernard Germain de Lacépède and Jean-Baptiste Lamarck succeeded in freeing Latreille.
In 1798, Latreille was appointed to the museum, where he worked alongside Lamarck, curating the arthropod collections, published a number of zoological works. Following the death of Guillaume-Antoine Olivier in 1814, Latreille succeeded him as titular member of the Académie des sciences de l'Institut de France. In the following few years, Latreille was productive, producing important papers for the Mémoires du Muséum, all of the volume on arthropods for George Cuvier's Le Règne Animal, hundreds of entries in the Nouveau Dictionnaire d'Histoire Naturelle on entomological subjects; as Lamarck became blind, Latreille took on an increasing proportion of his teaching and research work. In 1821, Latreille was made a knight of the Légion d'honneur. In 1829 he succeeded Lamarck as professor of entomology. From 1824, Latreille's health deteriorated, he handed his lectures over to Jean Victoire Audouin and took on several assistants for his research work, including Amédée Louis Michel Lepeletier, Jean Guillaume Audinet-Serville and Félix Édouard Guérin-Méneville.
He was instrumental in the founding of the Société entomologique de France, served as its honorary president. Latreille's wife died in May of that year, he resigned his position at the museum on 10 April 1832, in order to move to the country and thereby avoid the cholera epidemic. He returned to Paris in November, died of bladder disease on 6 February 1833, he was survived by a niece whom he had adopted. The Société entomologique raised the money to pay for a monument to Latreille; this was erected over Latreille's grave at Père Lachaise Cemetery, comprised a 9-foot obelisk with various inscriptions, including one to the beetle which had saved Latreille's life: "Necrobia ruficollis Latreillii salvator". As testimony to the high esteem in which Latreille was held, many books were dedicated to him, up to 163 species were named in his honour between 1798 and 1850. Taxa commemorating Latreille include: Lumbrineris latreilli Audouin & H. Milne-Edwards, 183
The drugstore beetle known as the bread beetle or biscuit beetle, is a tiny, brown beetle that can be found infesting a wide variety of dried plant products, where it is among the most common non-weevils to be found. It is the only member of the monotypic genus Stegobium; the drugstore beetle has a worldwide distribution. It is similar in appearance to the cigarette beetle, but is larger. Additionally, drugstore beetles have antennae ending in 3-segmented clubs, while cigarette beetles have serrated antennae; the drugstore beetle has grooves running longitudinally along the elytra, whereas the cigarette beetle is smooth. The drugstore beetle's larvae are small, white grubs, that can be distinguished from the grubs of the cigarette beetle by their shorter hair; the female can lay up to 75 eggs at once, the larval period lasts up to several months depending on the food source. It is the larvae; the drugstore beetle lives in obligatory symbiosis with a yeast fungus, passed on to the offspring by covering the eggs with it.
As its name suggests, the drugstore beetle has a tendency to feed on pharmacological products. This is from plant material sometimes used as drugs, it can feed on a diverse range of dried foods and spices, as well as hair, leather and museum specimens. It can bore in some cases tin foil or sheets of lead; the drugstore beetle is known as the biscuit or bread beetle since it can live on biscuit or bread crumbs. The most effective method of ridding a home of this beetle is to try to discover the source of the infestation. Drugstore beetles enter a home in bulk items like bird seed, grass seed, or dry pet food, where several generations of beetles can develop unnoticed until some of the adults leave to infest new locations. Telltale signs of infested items are shot-like holes puncturing the outside packaging of food items and pockmarking solid items like crackers and pasta, as well as loose powder at the bottom of storage bags. While adult beetles do not feed, they are adept at chewing holes. Once inside the home, the adult beetles will lay their eggs on a variety of foods including whole grains, processed grains and vegetative material.
Food sources which can become infested include grains, bread, seeds, pasta, bird seed, grass seed, spices and tobacco. While they are adept at chewing out of cardboard and plastic film to escape the package in which they have undergone metamorphosis to adults, they are somewhat less to eat into a sealed, airtight foil or plastic bag. Ideally, all open packages should be discarded in an infested home. Food storage areas like pantries and cabinets need to be vacuumed including the crevices between floor boards, the corners of cabinets, areas where mice may have hoarded things like dry dog food. A bird nest within a home can provide a haven for drugstore beetles, a professional may need to be consulted to address this. Lowering home humidity levels can be helpful as well. While the use of chemical insecticides may be undesirable in food storage areas, Food Grade diatomaceous earth can be useful sprinkled in corners or mixed into bird seed. Cornell University Insect Diagnostic Lab Factsheets drugstore beetle on the UF / IFAS Featured Creatures Web site
The Curculionidae are the family of the "true" weevils. They are one of the largest animal families, with 6,800 genera and 83,000 species described worldwide, they include the bark beetles as subfamily Scolytinae, which are modified in shape in accordance with their wood-boring lifestyle. They do not much resemble other weevils, so they were traditionally considered a distinct family, Scolytidae; the family includes the ambrosia beetles, of which the present-day subfamily Platypodinae was considered the distinct family Platypodidae. They are recognized by their distinctive long snouts and geniculate antennae with small clubs. With so many species to classify and over 400 genera, the taxonomy of this family is quite complicated, authors disagree on the number and placement of various subfamilies and subtribes; the phylogeny of the group is complex. A 1997 analysis attempted to construct a phylogeny based on larval characteristics. Recent work on the phylogenetic relationships in weevils mentions the two subfamily groups Adelognatha and Phanerognatha for the species of Curculionidae.
Two dozen subfamilies are recognized by some authors when merging those that are invalid. Others, recognize a lesser number – the only subfamilies that are universally considered valid are the Baridinae, Curculioninae, Entiminae, Molytinae and Scolytinae; the various proposed taxonomic schemes recognize as many additional subfamilies again, but little agreement is seen between authorities about which. In particular, the delimitation of the Molytinae has proven difficult; the subfamilies considered valid by at least some authors today: Bagoinae Baridinae Brachycerinae Conoderinae Cossoninae Cryptorhynchinae Acalles Curculioninae – flower weevils and nut weevils Cyclominae Dryophthorinae Entiminae – broad-nosed weevils Hyperinae Lixinae Mesoptiliinae Molytinae Orobitidinae Platypodinae – typical ambrosia beetles Raymondionyminae Scolytinae – bark beetles Xiphaspidinae Black vine weevil Boll weevil Pecan weevil Wheat weevil Hylobius Scolytoplatypus Pests and diseases of roses Media related to Curculionidae at Wikimedia Commons Data related to Curculionidae at Wikispecies Images of Curculionidae species found in New ZealandOn the University of Florida / Institute of Food and Agricultural Sciences Featured Creatures website: Anthonomus eugenii, pepper weevil Cylas formicarius, sweetpotato weevil Chalcodermus aeneus, cowpea curculio Cosmopolites sordidus, banana root borer Eudociminus mannerheimii, cypress weevil Eurhinus magnificus Gerstaeckeria spp.
Metamasius callizona, Mexican bromeliad weevil Metamasius hemipterus sericeus, silky cane weevil, Metamasius mosieri, Florida bromeliad weevil Naupactus spp. whitefringed beetles Oxyops vitiosa, melaleuca weevil Pantomorus cervinus, Fuller rose weevil Pseudocneorhinus bifasciatus, twobanded Japanese weevil Rhynchophorus cruentatus, palmetto weevil Sphenophorus venatus, hunting billbugOther University web pages on economically important curculids: Conotrachelus nenuphar, plum curculio from the Ohio State University Orchestes pallicornis, apple flea weevil from Michigan State University
Ptinidae is a family of beetles in the superfamily Bostrichoidea. There are 2,200 described species in Ptinidae worldwide; the family includes spider beetles and deathwatch beetles. There are three main groups in the superfamily Bostrichoidea: Bostrichidae and Ptinidae; these have undergone frequent changes in hierarchical classification since their inception. They have been treated as a single family, three independent families, the two families Bostrichidae and Anobiidae, or the two families Bostrichidae and Ptinidae. More recent literature treats these as the two families Bostrichidae and Ptinidae, with Anobiidae a subfamily of Ptinidae. Spider beetles are so named; some species have long legs, antennae that can seem like an additional pair of legs, a body shape that may appear superficially like that of a spider. Deathwatch beetles are named because of a clicking noise that two species tend to make in the walls of houses and other buildings; this clicking noise is designed to communicate with potential mates, but has caused fear of impending death during times of plague and sickness.
The larvae of a number of Ptinidae species tend to bore into wood, earning them the name "woodworm" or "wood borer". Several species are pests, causing damage to wooden furniture, house structures and dried food products; the deathwatch beetles Xestobium rufovillosum, Hemicoelus carinatus, Hemicoelus gibbicollis are economically significant pests, damaging flooring and other timber in housing. The "furniture beetle", Anobium punctatum, is a species, found emerging from in-home wood furnishings; the "drugstore beetle", Stegobium paniceum, is known to infest a variety of stored materials, including bread, cereal, prescription drugs, strychnine powder, packaged foods, Egyptian tombs. The "Cigarette beetle," Lasioderma serricornea, is a widespread and destructive pest of harvested and manufactured tobacco. Damage and economic losses from Lasioderma serricornea infestations were estimated by the USDA to be 0.7% of the total warehoused tobacco commodity in 1971. List of Ptinidae genera
Insects or Insecta are hexapod invertebrates and the largest group within the arthropod phylum. Definitions and circumscriptions vary; as used here, the term Insecta is synonymous with Ectognatha. Insects have a chitinous exoskeleton, a three-part body, three pairs of jointed legs, compound eyes and one pair of antennae. Insects are the most diverse group of animals; the total number of extant species is estimated at between ten million. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans. Nearly all insects hatch from eggs. Insect growth is constrained by the inelastic exoskeleton and development involves a series of molts; the immature stages differ from the adults in structure and habitat, can include a passive pupal stage in those groups that undergo four-stage metamorphosis. Insects that undergo three-stage metamorphosis lack a pupal stage and adults develop through a series of nymphal stages.
The higher level relationship of the insects is unclear. Fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonflies with wingspans of 55 to 70 cm; the most diverse insect groups appear to have coevolved with flowering plants. Adult insects move about by walking, flying, or sometimes swimming; as it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles, composed of the front & rear on one side with the middle on the other side. Insects are the only invertebrates to have evolved flight, all flying insects derive from one common ancestor. Many insects spend at least part of their lives under water, with larval adaptations that include gills, some adult insects are aquatic and have adaptations for swimming; some species, such as water striders, are capable of walking on the surface of water. Insects are solitary, but some, such as certain bees and termites, are social and live in large, well-organized colonies.
Some insects, such as earwigs, show maternal care, guarding their eggs and young. Insects can communicate with each other in a variety of ways. Male moths can sense the pheromones of female moths over great distances. Other species communicate with sounds: crickets stridulate, or rub their wings together, to attract a mate and repel other males. Lampyrid beetles communicate with light. Humans regard certain insects as pests, attempt to control them using insecticides, a host of other techniques; some insects damage crops by feeding on sap, fruits, or wood. Some species are parasitic, may vector diseases; some insects perform complex ecological roles. Insect pollinators are essential to the life cycle of many flowering plant species on which most organisms, including humans, are at least dependent. Many insects are considered ecologically beneficial as predators and a few provide direct economic benefit. Silkworms produce silk and honey bees produce honey and both have been domesticated by humans.
Insects are consumed as food in 80% of the world's nations, by people in 3000 ethnic groups. Human activities have effects on insect biodiversity; the word "insect" comes from the Latin word insectum, meaning "with a notched or divided body", or "cut into", from the neuter singular perfect passive participle of insectare, "to cut into, to cut up", from in- "into" and secare "to cut". A calque of Greek ἔντομον, "cut into sections", Pliny the Elder introduced the Latin designation as a loan-translation of the Greek word ἔντομος or "insect", Aristotle's term for this class of life in reference to their "notched" bodies. "Insect" first appears documented in English in 1601 in Holland's translation of Pliny. Translations of Aristotle's term form the usual word for "insect" in Welsh, Serbo-Croatian, etc; the precise definition of the taxon Insecta and the equivalent English name "insect" varies. In the broadest circumscription, Insecta sensu lato consists of all hexapods. Traditionally, insects defined in this way were divided into "Apterygota" —the wingless insects—and Pterygota—the winged insects.
However, modern phylogenetic studies have shown that "Apterygota" is not monophyletic, so does not form a good taxon. A narrower circumscription restricts insects to those hexapods with external mouthparts, comprises only the last three groups in the table. In this sense, Insecta sensu stricto is equivalent to Ectognatha. In the narrowest circumscription, insects are restricted to hexapods that are either winged or descended from winged ancestors. Insecta sensu strictissimo is equivalent to Pterygota. For the purposes of this article, the middle definition is used; the evolutionary relationship of insects to other animal groups remains unclear. Although traditionally grouped with millipedes and centiped