The insects of the beetle family Chrysomelidae are commonly known as leaf beetles, and include over 37,000 (and probably at least 50,000) 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 only some of them are listed below. 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 4th tarsal segment is very small and hidden by the 3rd. As with many taxa, there is no single character that defines the Chrysomelidae; instead it is delineated by a set of characters. 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, and all species are fully herbivorous. 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), 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.
|Scarlet lily beetle Lilioceris lilii in Oxfordshire, UK|
Latreille, 1802 
The imagos of leaf beetles are small to medium-sized, i.e. most species range from 1 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 elongate), 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 beatles 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.
The family includes the following 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, Synetinae, and Hispinae).
The Aderidae, sometimes called ant-like leaf beetles, are a family of beetles that bear some resemblance to ants. The family consists of about 1,000 species in about 50 genera, of which most are tropical, although overall distribution is worldwide.
As with the Anthicidae, their heads constrict just in front of the pronotum, forming a neck, although the posterior end of the pronotum is not usually as narrow. The eyes are hairy with a granular appearance. The first two abdominal sternites are fused, and in only some groups is a suture even visible. Sizes are 1–4 mm.
As the name suggests, most adults are found on the undersides of the leaves of shrubs and trees, while larvae have found in rotting wood, leaf litter, and nests of other insects.
As of 2002, the last publication of a world catalog of the family was that of Maurice Pic in 1910.
Synonyms of the family include:
Xylophilidae Shuckard 1840
Euglenesidae or Euglenidae Seidlitz 1875
Hylophilidae Pic 1900Cereal leaf beetle
The cereal leaf beetle (Oulema melanopus) is a significant crop pest, described by Carl Linnaeus in 1758.Chrysolina cerealis
Chrysolina cerealis, the rainbow leaf beetle or Snowdon beetle, is a beetle belonging to the family Chrysomelidae.Chrysomela
Chrysomela is a genus of leaf beetles found almost throughout the world, but missing from Australia. It contains around 40 species, including 7 in eastern and northern Europe. It also includes at least 17 species in North America, including the cottonwood leaf beetle Chrysomela scripta.Downham Woodland Walk
Downham Woodland Walk is a linear park and local nature reserve in Downham in the London Borough of Lewisham. It is also a Site of Borough Importance for Nature Conservation, Grade 1. The site is owned and managed by Lewisham Council.The walk dates back to the nineteenth century, and with the construction of the Downham housing estate in the 1920 it became an important green space for local residents. The eastern section between Moorside Road and Downderry Road existed in 1805, and it has a number of species indicative of ancient woodland, such as wood anemone and dog's mercury. West of Downderry Road the walk is narrower and the flora less diverse. The walk has a good variety of birds and a number of rare invertebrates, such as the leaf beetle Chrysolina oricalcia and the ant Lasius brunneus, while hawthorns have a population of the nationally scarce jewel beetle Agrilus sinuatus.The walk runs west from Moorside Road, opposite Undershaw Road, to cross Downderry Road, and then turns south to Oakridge Road. It then runs west again to finish at the junction of Oakridge Road and Bromley Road.Elm leaf beetle
Xanthogaleruca luteola, commonly known as the elm-leaf beetle, is an invasive beetle pest species in the family Chrysomelidae.Milkweed leaf beetle
The milkweed leaf beetle (Labidomera clivicollis) is a species of beetle from the family Chrysomelidae. Its range extends from the Rocky Mountains to eastern Maritimes Provinces and eastern United States.Neochlamisus
Leaf beetles of the genus Neochlamisus are sometimes known as the warty leaf beetles. 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. 17, sometimes 18 species are presently accepted in this genus, all of them occurring in North America (including Mexico; some were previously in the genus Chlamisus).Northern tamarisk beetle
Diorhabda carinulata is a species of leaf beetle known as the northern tamarisk beetle, which feeds on tamarisk trees from southern Russia and Iran to Mongolia and western China. This beetle is used in North America as a biological pest control agent against saltcedar or tamarisk (Tamarix spp.), an invasive species in arid and semiarid ecosystems (where D. carinulata and its closely related sibling species are also less accurately referred to as the 'saltcedar beetle', 'saltcedar leaf beetle', 'salt cedar leaf beetle', or 'tamarisk leaf beetle').Paraivongius motoensis
Paraivongius motoensis is a species of leaf beetle of the Democratic Republic of the Congo, observed by Burgeon in 1941.Scarlet lily beetle
The scarlet lily beetle, red lily beetle, or lily leaf beetle (Lilioceris lilii), is a leaf beetle that eats the leaves, stem, buds, and flower, of lilies, fritillaries and other members of the family Liliaceae. It lays its eggs most often on Lilium and Fritillaria species. In the absence of Lilium and Fritillaria species, there are fewer eggs laid and the survival rate of eggs and larvae is reduced. It is now a pest in most temperate climates where lilies are cultivated.Scelolyperus lecontii
Scelolyperus lecontii is a species of leaf beetle in the family Chrysomelidae. It is found in North America.Ulmus americana 'Iowa State'
The American Elm cultivar Ulmus americana 'Iowa State' was cloned from a tree discovered by Professor Alexander (Sandy) McNabb of Iowa State University as the sole survivor in 40 acres (16 ha) of diseased elm at Burlington.Ulmus americana 'Jackson'
The American Elm cultivar Ulmus americana 'Jackson' was cloned from a selection made at Wichita, Kansas, which had reputedly shewn no signs of Dutch elm disease damage at >50 years of age.Ulmus americana 'L'Assomption'
The American Elm cultivar Ulmus americana 'L'Assomption' was selected from seedlings grown from X-irradiated seed at the eponymous experimental station in Quebec before 1965.Ulmus americana 'Lake City'
The American Elm cultivar Ulmus americana 'Lake City' was first described by Wyman in Trees Magazine 3 (4): 13, 1940.Ulmus americana 'Littleford'
The American Elm cultivar Ulmus americana 'Littleford' was cloned from a tree in Hinsdale, Illinois, circa 1915 and first released in 1927.Ulmus americana 'Patmore'
The American Elm cultivar Ulmus americana 'Patmore' was selected and raised by R. H. Patmore from a native tree in Brandon, Manitoba, Canada. It may be synonymous with another cultivar from the same source, known as 'Brandon'.Viburnum leaf beetle
Pyrrhalta viburni is a species of leaf beetle native to Europe and Asia, commonly known as the viburnum leaf beetle. It was first detected in North America in 1947
in Ontario, Canada. However, specimens had been collected in Annapolis Royal, Nova Scotia in 1924.
In 1996 it was discovered in a park in New York, where native plantings of arrowwood (Viburnum dentatum complex) were found to be heavily damaged by larval feeding. The UK-based Royal Horticultural Society stated that its members reported Pyrrhalta viburni as the "number one pest species" in 2010. Female beetles burrow into viburnum terminal twigs and create 'spaces' in pith tissue. Then they lay eggs in clusters and cover them with frass. Eggs overwinter in these cavities where they are protected from water loss and predation.The spined soldier bug, Podisus maculiventris is used and developed as a biological control agent against the beetle.