Kissister mimimus (Laporte, 1840)
POLYPHAGA Emery, 1886
HYDROPHILOIDEA Latreille, 1802
DENDROPHILINAE Reitter, 1909
Kissister Marseul, 1862
This is a mostly western and central European species although it is also widespread across North Africa and occurs on Madeira and some of the Mediterranean islands, it extends from Portugal to Italy and Germany and north to the UK but has a rather patchy distribution and is likely to be under-recorded due to its small size and secluded lifestyle. In the UK it is very local and generally scarce; it occurs across East Anglia and the southeast below London and there are scattered records from the midlands but elsewhere it is mostly coastal, extending north to Anglesey. Adults are present year-round and are active over a long season from early spring, peaking in abundance during May and June. According to the literature they occur among plant roots, particularly Sheep’s Sorrel, Rumex acetosella L., and especially on dry sandy or stony soils, but this is only partly the case as we have recorded them from several locations in South Hertfordshire from winter Beech bark, Fagus sylvatica L.) and decaying heartwood samples, and during the spring and summer from bracket fungi on various broadleaved trees (including Trametes versicolor (L.) Lloyd (1920) on Beech) and extraction samples of mixed straw and horse manure, and in Spain and Morocco they are often associated with colonies of the ant Pheidole pallidula (Nylander, 1840) which is widespread in Mediterranean countries but is not known from northern Europe or the UK. Conversely we have swept them from long grass in our local Watford park during June, this site contains many mature broadleaved trees in various stages of decay and the specimens may have been dispersing from these trees by flight and settling among low vegetation. It seems likely that it is a more generalist species that develops among decaying organic matter, like many other members of the family, and that both adults and larvae are predatory, again like most other members of the family, and can exploit a range of biotopes. Adults may be swept from dry grassland and are also said to occur under stones etc among long dry grass, but in our experience the easiest way to find them is by sieving or extracting samples of old dry fungus and bark or samples of wood debris from tree hollows; at night they are sometimes active on the surface of trunks or fallen timber but they will need to be taken for examination as in the field they are easily mistaken for the common saproxylic species Abraeus perpusillus (Marsham, 1802).
Kissister minimus 1
Kissister minimus 2
1.0-1.8 mm. Broadly elongate-oval, convex and more or less continuous in outline, the small size and the form of the elytral striae will distinguish this species among the UK histerids. Body black or dark grey, appendages brown or reddish-brown. Head hypognathous and only narrowly visible from above, with transversely elongate eyes and short scrobes between the gena and the frons, antennae inserted in the scrobes near the lower margin of the eyes, 11-segmented with a short, curved scape, progressively more transverse funicular segments and an elongate oval and compact club. Pronotum transverse, broadest across the base and narrowed to slightly projecting anterior angles, anterior margin almost straight, basal margin gradually produced to the centre, surface evenly convex and very finely punctured. Prosternum with a projecting anterior lobe which is excavate laterally for the reception of the antennal scape, and cavities behind the coxae for the antennae club. Elytra slightly transverse, broadest about the middle and evenly curved laterally to a truncate apical margin which leaves the pygidium exposed, each with four striae which terminate before the apex; the innermost shorter than the others and curved at the base towards the suture, cuticle otherwise convex and finely punctured throughout. Legs long and robust with femora visible in normal setting. Front tibiae broadly expanded from the base, with four or five fine external teeth and a long and curved apical spur. Middle tibiae broadened from the base but much narrower than the front tibiae, usually with three or four external spines and two tiny curved apical spurs but these tend to get worn in life, hind tibiae weakly broadened in the apical half, usually with a single fine spine on the external margin towards the apex and two tiny apical spurs. Tarsi 5-segmented and simple.