drastically; with 700 species Meligethes included the majority of the species. The subfamily occurs worldwide but the widest diversity is in Afrotropical, Australasian and Oriental regions and the western Palaearctic region, including the UK, has a rich fauna. All species are anthophagous, occurring within the flowers of a wide range of herbaceous plants, shrubs and trees, adults tend to occur on flowers generally while the larvae are often oligophagous or monophagous. Epuraeinae Kirejtshuk, 1986 includes more than 400 species in 20 genera and two tribes; Epuraeini Kirejtshuk, 1986 12 genera and Taenioncini Kirejtshuk, 1998 with 8 genera. The group is widespread throughout the Old World but only poorly represented in the Americas e.g. the Nearctic fauna includes 32 species of the single genus Epuraea Erichson, 1843. The greatest diversity is in eastern Palaearctic and Oriental regions e.g. Epuraea includes almost 300 species in 17 subgenera, and of the 55 species of the subgenus Micruria Reitter, 1875 most occur in China and Japan while only a single species extends to Europe including the UK. The subgenus Epuraea Erichson, 1843 includes more than 200 species and is almost cosmopolitan. Formerly included within the Carpophilinae, they are distinctive elongate-oval and flattened species associated with a wide range of habitats and include mycetophagous, saprophagous and anthophagous species. The following two subfamilies include the majority of the species and, in temperate regions, display the widest morphological diversity. Cryptarchinae Thomson, 1859 is a relatively small group of >300 species in 16 genera and 4 tribes with a cosmopolitan distribution, they are abundantly distinct and distinguished from the other subfamilies by the following combination of characters: the labrum and frons are fused, the procoxae open, the tegmen without lateral lobes, the vertex bearing one row of stridulatory files and the vertex sometimes expanded over the antennal insertions. The group includes some of the most distinctive species e.g. in the UK the genera Glischrochilus Reitter, 1873 and Pityophagus Shuckard, 1839. Nitidulinae Latreille, 1802 is by far the most diverse subfamily with about 110 genera in 6 tribes and is cosmopolitan in distribution. Distinguished from the previous subfamily by the free labrum and from other subfamilies by the abbreviated elytra which reach at least some way across the propygidium (in Carpophilinae they are much shorter, exposing 2 or 3 tergites), the pygidium lacking impressed lines at the base (Meligethinae) and from Epuraeinae by a combination of morphological characters as well as the (generally) well-sclerotized genitalia-in Epuraea they are only slightly sclerotized.

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Description

Members are morphologically very diverse, they range from about 1mm to 20mm in length, although in temperate regions they rarely exceed 5mm, and vary from very elongate or oval and flattened to globose and convex species, many are pubescent and this varies from fine recumbent hairs to stiff and dense erect setae, colouration is generally rather drab but many have red or yellow markings and some are brilliantly coloured and metallic. The dorsal surface is usually finely and uniformly punctured and only a very few have distinct elytral striae or carinae, typically they are evenly convex and lack major structures, tubercles or depressions and in most the elytra are abbreviated leaving various abdominal segments exposed. All possess rather short antennae with a compact and distinct club, and this is often the best clue to the family. The following description covers the family generally-there are exceptions in exotic genera- but our UK fauna is diverse and a familiarity will allow much of the northern temperate fauna (and much else) to be recognized to family level; nitidulids are a diverse group that are difficult to key to the family level or encapsulate within a description but rather straightforward to become familiar with through looking at pictures or a reference collection. Head usually transverse and devoid of major structure; prognathous to moderately declined and with moderately to strongly convex and entire to weakly emarginate eyes, and temples that converge towards the base. Clypeus truncate to emarginate, frontoclypeal suture weakly impressed or absent, and the labrum is free (except in Cryptarchinae), transverse and apically bilobed. Mandibles usually unidentate; lacking dorsal cavities or tubercles but with a well-developed molar and subapical tooth. Mentum transverse and apically emarginate. Apical segment of labial palpi fusiform. Antennae 11-segmented with a short and broad basal segment and well-defined and compact 3-segmented club, usually mounted laterally in front of the eyes, the insertions often concealed by a lateral expansion of the frons. Pronotum transverse to quadrate, only rarely elongate, widest at the middle or towards the base and as broad as the elytra across the shoulders, laterally bordered and often explanate, sometimes very widely so. Pronotal angles usually well-defined; anterior angles often produced forward, posterior angles rounded to slightly acute, basal margin straight, weakly rounded or bisinuate. Surface weakly to strongly convex and without major structure although in many there are basal fovea or weakly depressed or flatted areas. Prosternum about as long as a procoxal cavity, with a well-developed and diverse process, procoxal cavities round or nearly so and closely to widely separated and generally closed although open in Cryptarchinae and Amphicrossinae. Scutellum usually relatively large, flat and apically acute or rounded. Elytra transverse to elongate (up to 2X longer than wide), strongly to weakly rounded laterally and continuously or separately rounded or truncate apically so leaving the at least the pygidium exposed. Epipleurs usually strongly developed towards the base but often incomplete, disc usually randomly punctured but in some with up to 10 punctured striae, but without a scutellary striole, these sometimes alternating with variously developed longitudinal carinae. Hind wings in most cases are well-developed although usually with a reduced venation. Abdomen with 5 free ventrites, the basal 2 subequal in length, intercoxal process acute to broadly rounded and sometimes with curved or angled post-coxal lines. Legs short and robust; procoxae round and variously projecting, mesocoxae transverse and usually broadly separated, metacoxae transverse and widely separated, trocanters exposed and obliquely joined to broad femora and unarmed femora, tibiae moderately to strongly broadened towards the apex; pro- and mesotibiae variously crenulate or toothed externally, in Meligethes the protibial teeth afford excellent identification characters . Tarsi 5-segmented in both sexes; the basal segments usually dilated and setose ventrally, in e.g. Pocadius Erichson, 1843 and Soronia Erichson, 1843 they are simple, the fourth segment almost always the smallest but not enclosed by the lobes of the third., claws simple or with a basal tooth.

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Ecology

Many species are attracted to the sap exuded by trees in response to local damage on areas of otherwise healthy bark, they are attracted by various volatiles and tend to remain for long periods, often feeding in numbers where the sap runs along crevices, and very often several species will be present alongside one another. Otherwise the habits are varied and species will be found under bark, on flowers, especially blossom in the spring, on fruit, decaying fungi, among decaying vegetation or at any fermenting plant tissue and a few (e.g. species of Nitidula Fabricius, 1775 or Omosita Erichson, 1843) occur at carrion. Only a few species have become pests of crops or stored products, they are generally a only a nuisance but large numbers can prove economically damaging because of the adult and larval feeding habits and also because they are recognized as vectors of pathogenic fungi; among the most notorious of these are various Carpophilus and Glischrochilus which occur sporadically among stored fruits etc. the strawberry sap beetle, Stelidota geminata (Say, 1825) and the yellowish-brown sap beetle Epuraea luteolus (Erichson, 1843) attack both dried and growing fruits whereas the dried fruit beetle, Carpophilus hemipterus (Linnaeus, 1758) attacks stored fruit and various Carpophilus attack stored as well as growing grains etc.  The small hive beetle, Aethina tumida Murray, 1867, is a destructive pest in honey-bee hives and also ruins stored honey, the destruction is caused by larvae which destroy combs and caps, ruin honey by defacation and leaving discarded moultings etc. and by introducing fungi which may ferment the honey, other species are also becoming invasive in hives but predation is rare among Nitidulids; many fungivorous species have been observed to consume larvae etc. under bark but it is unknown among larvae and among the few known exclusively predatory adults are various Pityophagus Schuckard, 1839 which predate bark-beetle larvae, Cychramtodes murrayi Reitter predates the coccid Cryptes baccatus (Maskell, 1892), and Amphicrossus japonicus Reitter, 1873 breeds in water-filled bamboo stems where it predates mosquito larvae. A very few species are associated with ants and termites.

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