Leaf beetles Temporal range: | |
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Scarlet lily beetle Lilioceris lilii in Oxfordshire, UK | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Coleoptera |
Infraorder: | Cucujiformia |
Superfamily: | Chrysomeloidea |
Family: | Chrysomelidae Latreille, 1802 [1] |
Subfamilies | |
See text |
The insects of the beetle family Chrysomelidae are commonly known as leaf beetles, and include over 37,000 (and probably at least 50,000)[ citation needed ] species in more than 2,500 genera, making up one of the largest and most commonly encountered of all beetle families. Numerous subfamilies are recognized, but the precise taxonomy and systematics are likely to change with ongoing research.
Leaf beetles are partially recognizable by their tarsal formula, which appears to be 4-4-4, but is actually 5-5-5 as the fourth tarsal segment is very small and hidden by the third. [2] As with many taxa, no single character defines the Chrysomelidae; instead, the family is delineated by a set of characters. [3] Some lineages are only distinguished with difficulty from longhorn beetles (family Cerambycidae), namely by the antennae not arising from frontal tubercles.
Adult and larval leaf beetles feed on all sorts of plant tissue. Many are serious pests of cultivated plants, for example the Colorado potato beetle (Leptinotarsa decemlineata), the asparagus beetle (Crioceris asparagi), the cereal leaf beetle (Oulema melanopus), the mustard beetle (Phaedon cochleariae) and various flea beetles, and a few act as vectors of plant diseases. Others are beneficial due to their use in biocontrol of invasive weeds. Some Chrysomelidae are conspicuously colored, typically in glossy yellow to red or metallic blue-green hues, and some (especially Cassidinae) have spectacularly bizarre shapes. Thus, they are highly popular among insect collectors.
The imagos of leaf beetles are small to medium-sized, i.e. most species range from 1.0 to 18 mm in length, excluding appendages, with just a few larger species such as Alurnus humeralis, which reaches 35 mm. The bodies of most species are domed, and oval in dorsal view (though some are round or elongated), and they often possess a metallic luster or multiple colors. In most specimens, the antennae are notably shorter than head, thorax, and abdomen, i.e. not more than half their combined length. The second antennal segment is of normal size (which differentiates leaf beetles from the closely related longhorn beetles). In most species, the antennal segments are of a more or less equal shape, at most they gradually widen towards the tip, although some Galerucinae in particular have modified segments, mainly in males. The first segment of the antenna in most cases is larger than the following ones. The pronotum of leaf beetles varies between species. In most, it is slightly to highly domed and trapezoidal to rounded-squarish in dorsal view. In some subfamilies such as the Cassidinae and to a lesser extent the Cryptocephalinae, the head is covered by the pronotum and thus not visible from above. The first three sternites are not fused, instead being linked by mobile sutures. Most species possess wings, although the level of development and thus flight ability varies widely, including within a single species, and some are flightless with fused elytra. [4]
The family includes these subfamilies:
Until recently, the subfamily Bruchinae was considered a separate family, while two former subfamilies are presently considered families (Orsodacnidae and Megalopodidae). Other commonly recognized subfamilies have recently been grouped with other subfamilies, usually reducing them to tribal rank (e.g., the former Alticinae, Chlamisinae, Clytrinae, and Hispinae). The extinct subfamily Protoscelidinae, containing fossils described from the Middle to Late Jurassic Karabastau Formation, Kazakhstan, has been transferred to the family Anthribidae. [5]
Chrysomelidae in general are herbivorous. Adults mostly feed on leaves and flowers of angiosperm plants, while larval diets are diverse. [6]
A Finnish researcher published an exhaustive paper describing the natural enemies of the alder leaf beetle Plagiosterna aenea and other species of leaf beetles observed in the field. [18] Predators of chrysomelid eggs include true bugs such as Anthocorus nemorum and Orthotylus marginalis. [19] Hoverflies (e.g. Parasyrphus nigritarsis ) sometimes lay eggs adjacent to beetle egg clutches and when the fly larva hatches it consumes beetle eggs and young larvae. [19] Larval predators include A. nemorum, the bug Rhacognathus punctatus , [19] and the wasp Symmorphus bifasciatus . [20] Some species of wasps, such as Polistes carolina , have been known to prey upon Chrysomelidae larvae after the eggs are laid in flowers. [21] Adult beetles are consumed by R. punctatus. [19] More information about natural enemies can be found in the articles about the chrysomelid beetles Chrysomela aeneicollis, Phratora laticollis and Phratora vitellinae.
The tansy beetle is a species of leaf beetle. The common name derives from its main foodplant, Tansy, but it can also use other wetland plants such as Gypsywort and Water Mint. It measures 7.7–10.5 mm in length and has a characteristic bright metallic green colouration, with pitted elytra and a coppery tinge. In addition to the nominotypical subspecies, which repeats the specific name, C. graminis graminis, there are five further distinct subspecies of Tansy beetle, which, collectively, have a Palearctic distribution, although in the majority of countries where it is found the species is declining. In the United Kingdom it is designated as 'Nationally Rare'. The stronghold population here is located along the banks of the river Ouse in York, North Yorkshire. Other, small, fenland populations exist at Woodwalton Fen and at Welney Wildfowl and Wetlands Trust (WWT) reserve.
The flea beetle is a small, jumping beetle of the leaf beetle family (Chrysomelidae), that makes up the tribe Alticini which is part of the subfamily Galerucinae. Historically the flea beetles were classified as their own subfamily.
Neochlamisus is a genus of leaf beetles in the tribe Fulcidacini. They are members of the case-bearing leaf beetle group, the Camptosomata. Measuring 3–4 millimeters in length as adults, they are cryptic, superficially resembling caterpillar frass. Seventeen, sometimes 18 species are presently accepted in this genus, all of them occurring in North America.
The Chrysomelinae are a subfamily of leaf beetles (Chrysomelidae), commonly known as broad-bodied leaf beetles or broad-shouldered leaf beetles. It includes some 3,000 species around the world.
The Cryptocephalinae are a subfamily of the leaf beetles (Chrysomelidae), and belong to the group of case-bearing leaf beetles called the Camptosomata. The cases are made from the feces of larvae, passed from one instar to the next, and ultimately serves as a pupation chamber.
The Eumolpinae are a subfamily of the leaf beetles, or Chrysomelidae. It is one of the largest subfamilies of leaf beetles, including more than 500 genera and 7000 species. They are oval, and convex in form, and measure up to 10 mm in size. Typical coloration for this subfamily of beetles ranges from bright yellow to dark red. Many species are iridescent or brilliantly metallic blue or green in appearance.
The Cassidinae are a subfamily of the leaf beetles, or Chrysomelidae. The antennae arise close to each other and some members have the pronotal and elytral edges extended to the side and covering the legs so as to give them the common name of tortoise beetles. Some members, such as in the tribe Hispini, are notable for the spiny outgrowths to the pronotum and elytra.
The Megalopodidae are a small family of leaf beetles, previously included as a subfamily within the Chrysomelidae. One of its constituent subfamilies, Zeugophorinae, has also frequently been treated as a subfamily within Chrysomelidae. The family contains approximately 30 genera worldwide, primarily in the nominate subfamily Megalopodinae, and mostly circumtropical.
Camptosomata are the case-bearing leaf beetles or camptosomates, named for their larval habit of carrying a case of waste material. This group consists of two subfamilies of Chrysomelidae : Lamprosomatinae and Cryptocephalinae.
Samarendra Nath Maulik was an Indian entomologist who worked at the Natural History Museum, London and specialized in the systematics of the leaf beetles. He worked briefly at the University of Calcutta as a professor of Zoology. A structure on the hind femur, particularly of flea beetles, and used in their leaping motion has sometimes been called as "Maulik's organ".
Chrysolina americana, common name rosemary beetle, is a species of beetle belonging to the family Chrysomelidae.
The thistle tortoise beetle is a species of beetle in the subfamily Cassidinae and the genus Cassida. The thistle tortoise beetle can be recognized by its green, rounded back and it can be found on thistle plants in many regions of North America and Europe. The thistle tortioise beetle was first discovered in 1902 in Lévis, Quebec. In 1931, Nellie F. Paterson was the first to document the mature larva. Later, the instar larva of this species was first recorded in 2004 by Jolanta Świętojańska. The thistle tortoise beetle exhibits multiple defense behaviors, such as a flexible shield, providing a barrier against the mandibles of predators, and an excretion that protects the eggs as well.
The fecal shield is a structure formed by the larvae of many species of beetles in the leaf beetle family, Chrysomelidae. It is composed of the frass of the insect and often its exuviae, or bits of shed exoskeleton. The beetle may carry the shield on its back or wield it upon its posterior end. The main function of the fecal shield is defense against predators. Other terms for the fecal shield noted in the literature include "larval clothing", "kotanhang", "faecal mask", "faecal pad", and "exuvio-faecal annex".
Phratora vitellinae, the brassy leaf beetle, formerly Phyllodecta vitellinae, is a beetle of the family Chrysomelidae found in Europe and Asia. It feeds on Populus and Salix species. The evolution of its host plant preferences and the mechanism by which it uses host plant chemicals to make a larval defensive secretion have been the subject of intense study by research groups in Europe and the Nordic countries.
Chrysolina coerulans, also known as the blue mint beetle or blue mint leaf beetle, is a species of beetle in the family Chrysomelidae. It is a member of the subgenus Synerga of the genus Chrysolina. It is native to a wide range of countries between mid and eastern Europe and lives alongside rivers and in meadows, it feeds on various plant members of the mint family.
Phratora laticollis is a species of leaf beetle found in Europe and Asia. This beetle is found on Populus species and the chemistry and production of its larval defensive secretions and host plant relationships have been studied extensively.
Brachycoryna is a genus of tortoise beetles and hispines in the family Chrysomelidae. There are seven described species in Brachycoryna.
Shinsaku Kimoto was a Japanese entomologist specialising in the Leaf beetle family (Chrysomelidae).
Parasyrphus melanderi is a flower fly that is best known as a larval predator on the leaf beetle Chrysomela aeneicollis in the Sierra Nevada range of California.
Phratora tibialis is a species of leaf beetle found in Europe and parts of Asia. This beetle is found on willows and the chemistry and production of its larval defensive secretions and host plant relationships have been studied extensively.