• EUPARIINI SCHMIDT, 1910 is a worldwide group of about 350 species in 31 genera but they are very close to other tribes e.g. Psammodiini Mulsant, 1842, many genera are not well understood and so the number of genera and species will be found to vary. The group is well-represented in temperate regions although only 2 species of the single genus Saprosites Redtenbacher, 1858, a worldwide group of 130 species, occur in the UK.

• ODOCHILINI RAKOVIĈ, 1987 includes 17 Asian and southeast Asian species of the single genus Odochilus Harold, 1877.

• ODONTOCHILINI STEBNICKA & HOWDEN, 1996 is a small tropical group of 33 species in 7 genera, they occur in Australia, Africa and the New World.

• PROCTOPHANINI STEBNICKA & HOWDEN, 1995 is a small group of 30 species in 5 genera, the distribution is mostly Old World tropical regions and only a single species, the African Australaphodius frenchi (Blackburn, 1892) which has been introduced into Australia and Chile, occurs in the New World.

• PSAMMODIINI MULSANT, 1842 is a worldwide group of 90 species in 15 genera, it is well-represented in northern temperate regions and 7 species of 6 genera are included in the UK list.

• RHYPARINI SCHMIDT, 1910 is a pantropical group of about 80 species in 11 genera although only one occurs in Africa; it is mostly Old World with only 17 species of 5 genera occurring in tropical America. They are highly modified species associated with termites and have formerly been considered as a distinct subfamily.

• STEREOMERINI HOWDEN & STOREY, 1992. Includes 17 species of 7 genera distributed around Southeast Asia, Indonesia and Australasia, the there is a single New World species from Peru. They are all small and flattened species associated, so far as is known, with termites.

• TERMITODERINI includes a few species of the African genus Termitoderus Mateu, 1966 and the Peruvian monogeneric Termitaxis Krikken, 1970. All are highly modified species associated with termites. Termitaxis is often included within the Stereomerini and its placement is questionable but the single known specimen from which it was described is now missing.

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While the status of the subfamily is sound the relationships between the tribes are far from settled and it does not help that new material from relatively unexplored regions regularly appears. The status, or rather the extent, of the Aphodiini is unclear and various other tribes e.g. Didactyliini and Proctophanini are often combined into single tribes or considered as subtribes of the Aphodiini.

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Collecting

The subfamily provides a satisfying group of beetles for study as they are diverse and many are abundant although as with all such groups there are a number of rare or very local species, they are readily collected by the most basic methods of pulling apart dung etc. or by netting them in flight, they can be sampled using various baited water traps or a whole dung sample can be easily assessed by dropping it into water and capturing the beetles as they escape. Many species will come to light and they are common in flight-interception traps, they will regularly turn up in extraction samples and flood refuse through the winter and will occasionally occur when working compost etc. Further advantages of working the group are the ready availability of larvae from host material, the ease of setting and working with relatively large specimens and the availability of really good keys for the UK fauna. With experience many of our species will become obvious in the field and most of the UK species are easy to identify, a reference collection can quickly be assembled but even difficult species will soon become straightforward.

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Biology

Most species are of a typical elongate-oval and rather parallel-sided form, they are convex and generally lack the adornments seen in some other scarabaeiod groups although sexual dimorphism is common and usually expressed as tubercles to the head or pronotum of males. The dorsal surface may be glabrous or finely pubescent, often only in part, and while many are dark coloured or drab there are also brightly coloured or patterned species. Members of the Aphodiini are generally smoothly convex although the elytral striae may be deeply impressed or strongly punctured and the interstices strongly convex or carinate, and while the subfamily lacks the extremes of development seen in some groups of Scarabaeidae there are some morphologically interesting species, especially among those associated with termites but even among the UK fauna there are some interesting species e.g. Oxyomus sylvestris (Scopoli, 1833) and Diastictus vulneratus (Sturm, 1805) have the pronotum longitudinally impressed and in both Psammodius asper (Fabricius, 1775) and Brindalus porcicollis (Illiger, 1803) the pronotum has very strong transverse sculpture.  Briefly, the group is characterized by the following combination of characters: Head with mandibles reduced and covered by an expanded clypeus, maxillae with lacinia and galea separate, antennae 9-segmented with a short and pubescent 3-segmented club. Mesocoxae usually almost contiguous. Tibiae with well-developed external teeth, metatibiae usually with 2 apical spurs. Abdomen with 6 ventrites, the pygidium at most only partly visible beyond the elytral apex. Tarsi 5-segmented and simple; without expanded segments and usually with distinct claws. Among the UK fauna only members of the Aegialiinae Laporte, 1840 might be confused with the present subfamily; here the labrum is visible in front of the clypeus and the eyes are hidden when the specimen is viewed from above, in Aphodiinae the eyes are usually clearly visible and the labrum hidden when viewed from above. Members of the Aegialiinae do not occur in dung but are associated with decomposing vegetation on dry and sandy soils, usually at or near the coast.

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The group includes mostly small beetles, typically between 3 and 10mm in length, and only a few exotic species exceed 15mm, otherwise the common name is rather misleading because while a good proportion, probably the majority, develop in dung they are otherwise very diverse in habitats and ecology; many are detritivores as well as dung feeders, some are saprophagous or fungivores, while some may be predatory and there are many inquilines with ants and termites. Some adults have reduced mandibles and are thought to feed primarily on yeast- or bacteria-rich fluids in dung and decaying organic material. Habitats are typically those with a concentration of host material e.g. dung pasture or rabbit-grazed grassland but many occur among dung in woodland or on sand dunes etc. and, typical of such ephemeral situations where competition for food is often fierce, several or many species often occur together, conversely some are specialized, occurring in only certain habitats or on certain soil types or utilizing the dung of only certain animals. An idea of habitat diversity can be gained from a recent survey of Neotropical species where they were found in coastal sand dunes, sub-Antarctic beech forest, Patagonian steppe, high altitude Andean grassland and temperate and tropical rainforest. Of those species developing in dung the vast majority will be found in that of herbivores, probably because this is by far the most abundant and reliable host material. Many species are seasonal; the majority will be found during the warmer months, either continuously through the season or with well-defined spring, summer or autumn periods of adult occurrence but many overwinter in the soil as adults and a few are may only be found in the autumn and winter. Adults fly well and disperse more or less continuously through the season, as would be expected from the lifestyle, most are diurnal but a few, in the UK most notably Acrossus rufipes (Linnaeus, 1758), are crepuscular or nocturnal and occur regularly at light. Most species occur in large or very large populations and are abundant where they occur but they may be very local and many factors may influence their choice of habitat e.g. dung type or the availability of dung at a certain stage of drying out or decomposition, weather conditions or exposure, aspect, soil type and moisture content or competition from other coprophages.  Members do not burrow or bury dung although adults may occur in the soil during adverse conditions in the summer, most species-so called endocoprids-complete their life-cycle and spend most of their time within or among the host material, typically dung or decomposing vegetable material although some are known to be parasitic, entering the burrows of dung-burying species such as Geotrupes and laying eggs so that their larvae may develop within the dung provided by the host for their offspring. Adults are attracted to dung of a certain age, often freshly deposited, and they soon arrive in numbers by flight; a good demonstration of this can be had by disturbing a dung pat which is not colonized and fairly fresh on a warm summer day as at least some species will generally turn up within a few minutes, sometimes they remain in flight around the pat and form impressive swarms and sometimes they alight and sit on the surface waiting for mates or dive in within seconds. Some species may be observed swarming in apparently unsuitable habitats e.g. in woodland or marginal situations in the spring and sometimes the host material may not be obvious e.g. we once found huge numbers of Euorodalus coenosus (Panzer, 1798) by breaking open apparently dry rabbit droppings from shaded woodland borders in the New Forest, some droppings were crammed with 5 or 6 beetles and it was difficult to imagine this as a suitable environment for larval development, and nearby was one of the few UK sites for Liothorax niger (Illiger, 1798): an area of waterlogged meadow around a cattle pond exposed to the sun; two very different habitats! Males compete and signal for mates on the substrate and mating occurs either on the substrate or on the ground nearby. Females lay small batches of eggs within the substrate and often visit several sites to oviposit, larvae develop and pupate within the substrate or in the ground beneath and adults generally eclose within days, or at most a week or two, development is usually rapid and in temperate regions most species are univoltine and seasonal, often appearing in spring and/or autumn and sometimes aestivating in the soil during the warmest periods of summer.