Aphodius sphacelatus (Panzer, 1798)
Widespread and common throughout England, Wales and Scotland in various types of dung, also in decaying vegetable matter and decaying fruiting fungi. Very often found (in dung) with Aphodius prodromus (Brahm) with which it may be confused. In the field A.sphacelatus appears smaller when the two are found together, especially in numbers. Abundant in the spring; during warm days in early March they are on the wing throughout Whippendell Wood and by April samples of horse dung contain them, along with A.prodromus, by the hundred. They remain abundant until at least May when numbers decline rapidly. Winter grass tussock samples from the wood sometimes contain them, as does flood refuse in Cassiobury park. Adults reappear in the autumn; by October cattle dung on Croxley moor contains adults but not, it seems, anywhere near the numbers seen in spring.

4-6mm. Head microsculptured and punctate, black, obtusely projecting in front of eyes and with frontoclypeal suture usually distinct. Palpi brown to black, antennae brown club darker. Pronotum shining, with large and small punctures (X20), finely bordered laterally and posteriorly. Front angles broadly yellow, lateral and basal margins yellow but sometimes very narrowly so across base. Scutellum equilateral. Elytra distinctly patterned although this is often evanescent, in male pubescent apically to beyond middle laterally, in female apically only but sometimes appearing glabrous at X20. Eighth stria continues almost to base where it joins the seventh as a series of punctures. Where the frontoclypeal suture is indistinct (if necessary view transversely across the head in strong light, it usually helps) the continuation of the eighth stria seems the most distinctive and decisive character.

Description from 6 Watford specimens at X20

See ID Aids A.prodromus/A.sphacelatus