Worcestershire Record No. 3 November 1997 p. 3

LYCOPERDINA BOVISTAE (ENDOMYCHIDAE)

New Beetle National Rarity On A Different Fungus Than Usual

I visited the newly acquired Cruise Hill Wood reserve, near the Knapp and Papermill reserve at Alfrick, in October for photographs, and searched in leaf-litter for to-be-overwintering beetles and flies and snails, finding also a single earth star fungus that was just poking above the leaf litter, disconnected from the ground but supported upright by its down-curled, star-point lobes. I took the fungus home (it was eventually identified as sessile earthstar Geastrum fimbriatum by John Meiklejohn after we had checked the spore diameter) then left it indoors on a cool window ledge in a tall-sided, open margarine container. Three days later, two shiny dark brown beetles (photo, drawing), that were new to me, with a rather pointed elytra (wing cases), were running trapped in the container. They had exited the drying globular body of the fungus, because they were irritated by reduced humidity, and possibly the rise in temperature as evaporation stopped. I mean "irritated" in a the biological sense, of when an organism reacts to a physical stimulus. The habits of beetles are very much influenced by humidity.

After microscopic examination of the beetles, the British beetle identification key, Joy 1932, the most modern key available for the family, indicated this beetle was Lycoperdina bovistae (of family Endomychidae). Beetle check list, Pope (1977) showed no taxonomic changes to the genus Lycoperdina since Joy (1932); neither did Hodge and Jones (1995), the now standard reference work listing beetle species not in Joy. With this particular species the risk of identification error seemed low, as it is of very characteristic body shape, has an indented longitudinal line on each side that may be seen in the illustrations, the antennae are slightly and evenly widened towards the tip, the elytra (wing cases) have no black marking, and the apex of the elytra is rather pointed. It is described in Fowler (1889) as a "curious looking and conspicuous insect". But since Fowler (1889) another similar rarer British species, one with less pointed elytra and transversely black marked elytra, has been discovered for the genus. Joy describes both species. There are more modern British keys to many other beetle families - the German language many-volumed beetle keys Die Käffer Mitteleuropas by Freude et al are often used in Britain especially when there is no modern British key; but despite being 66 years old, more readable two-volumed old Joy remains useful so it has just been reprinted. Essential was Paul F. Whitehead as a long-term beetle specialist, who was able to confirm my identification.

The beetle I found is listed in Hyman (1994) as a nationally rare (RDB 3), very local, recorded in only three vice counties since 1970; but by old records previously widely spread in some southern counties, and as far north as Leicestershire, but never recorded in Worcestershire. Paul Whitehead, who has been very active in Worcestershire confirmed its newness. Worcestershire BRC have no previous record. Of additional interest, the beetle is associated with certain puffball fungi rather than earthstars.

To investigate how numerous the beetle was at Crews Hill, and to see if it could be found there in puffballs as the usual fungus, I revisited the wood a week later. Entering on the well-used north end public footpath, I discovered I was walking over many common earthstars Geastrum triplex partly hidden in leaf-litter. Pulling some of their onion-shaped bodies apart, inside a strong outer membrane they were damp and powdery. Close examination with a lens revealed Lycoperdina bovistae beetles embedded within. Nearby, a patch of clusters of common puffballs Lycoperdon perlatum, and stump puffball L. pyriforme on rotten wood, contained more as well, indicating that there are plentiful numbers of the beetle in the wood - because these fungi are so common, and my initial find of the beetle was distant. Fowler (1889) remarks that the beetle is very local, but generally found in numbers. (The fungi species are all well described in Pegler et al 1995)

Coincidentally at the nearby Knapp and Papermill reserve, interest in various species of earthstars by the wardens (Stuart and Tina Corbett, see Worcestershire Wildlife News January 1997) resulted in the beetle appearing in insect boxes in which earthstars were contained. So it is likely the population may extend to further local woodland and beyond, in total forming a northerly local population relative to the rest of the British populations in S. Hampshire, E. Sussex, W. Norfolk.

The beetle is a nationally significant addition to the recorded Worcestershire fauna.

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