Pseudotriphyllus suturalis (Fabricius, 1801)

This generally rare species has a mainly southern distribution in Europe, extending from Spain, where it is known from only a few records, to the Balkans, Greece, Romania and Ukraine, and to the north extending to Germany, the UK and possibly Poland although records there are not confirmed. Across much of this range it is very rare e.g. it is classed as critically endangered in Germany and as near-threatened in Austria, but in the UK it is widespread and sometimes locally common in central and eastern England; it is absent from most of the southern coastal counties and the West Country and sporadic and very scarce further north to south-east Scotland. Our local park and woodland in Watford, South Hertfordshire, would therefore seem to be a hotspot for the species as it has been abundant here each year since 2005 and is probably the commonest local member of the family. Typical habitats are old established woodland and wooded parkland and pasture where the beetles occur among fruiting bodies of the fungus Laetiporus sulphureus (Bull.) Murrill (1920), usually on injured or decaying parts of oak or beech but sometimes on other broadleaf trees, adults are present year-round and may be abundant through the winter. Adults are nocturnal and attracted to the fungus in all stages of development and decay; they are easily observed at night on the surface of fruiting bodies or tapped into a net during the day, they often occur under bark near the fungus and they also remain on dry and crumbly parts of the fungus that have fallen to the ground in the summer, and when this becomes waterlogged and slimy through the winter the beetles remain in numbers among the decaying tissue or in surrounding leaf-litter. Adults often seem to be more abundant through the winter and unlike the rest of the year they are often the only beetle species present, extractions of suitable material almost always produce numbers of adults and they sometimes occur among extractions of other fungi. On the continent they have also been recorded from the following fungi, Cerioporus squamosus (Huds.) Quélet (1886), Fistulina hepatica (Schaeff.) With. (1792), Pleurotus ostreatus (Jacq. Ex Fr.) and Phallus impudicus L. (1753).