Ablattaria laevigata (Fabricius, 1775)

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POLYPHAGA Emery, 1886

STAPHYLINOIDEA Latreille, 1802

SILPHIDAE Latreille, 1806

SILPHINAE Latreille, 1806

SILPHINI Latreille, 1807

Ablattaria Reitter, 1885

Often included in the genus Silpha Linnaeus, 1758, this is the only widespread European member of the present genus; two other species are present but both are restricted to Greece and the Near East. A. laevigata is a very local insect of southern and central Europe, extending from Spain to Ukraine and Turkey in the south, and north to the UK; it is present in Germany and Poland but otherwise absent from the Baltic counties and the UK seems to represent the northern limit of its distribution. Here it is mostly restricted to England south of the Wash; it is mostly coastal in the West Country and there are a few records further north as far as Nottingham and from the south Welsh coast. Typical habitats are open grassland or scrub with patchy vegetation, usually on light sandy or chalky soil and usually exposed to the sun or at least in sheltered warmer situations, adults live among tussocks or under debris etc. and are mostly nocturnal but in warm weather they become active and may be encountered as they roam the soil or climb grass stems; they are generally common in the South Buckinghamshire and South Hertfordshire Chilterns and we have often seen them on pathways and chalk escarpments and recorded them by sweeping long grass on sun-exposed hillsides, and we even found one on the steps of Watford Junction station (June 2013) when setting out on a recording trip. Adults are active from April until October but probably overwinter as we have found single specimens in January and they have been recorded in every month in southern Europe, they are specialist pulmonate snail predators and prey species include the white garden snail (Theba pisana (Muller, 1774) and species of Monacha Fitzinger, 1833, Xeropicta Monterosata, 1892 and Candidula Kobelt, 1871, and they have been observed to gnaw through shells and feed on the tissue of living snails. Mating pairs have been recorded in the spring and larvae develop rapidly in spring and early summer, they resemble large shiny black woodlice and are very active terrestrial snail predators although they also climb grass stems, but unlike the adults they curl around the outside of the shell, gripping it with their long and robust legs, and attack the snail through the opening, the larval head is elongate and equipped with long three-segmented antennae which they rapidly and constantly move when prey is detected. Having attacked a snail the larva will enter the shell and devour the entire contents, several snails will be consumed and the larva will rest and moult inside the shell before leaving to find further prey. Fully grown larvae enter the soil to pupate and pupae may be recognized as the developing pronotum, distinctive in the adult, is fully visible, adults eclose after a week or so but remain in the soil for a few days ; they are entirely dull orange before they begin to harden and darken prior to emergence.

Abblataria laevigata 1

Abblataria laevigata 1

Abblataria laevigata 2

Abblataria laevigata 2

Ablattaria laevigata 3

Ablattaria laevigata 3

Adults are easily recognized among our fauna by the large size, elongate head and smooth elytra. 10-18mm. Entirely dull black, head and pronotum finely and densely punctured, elytra more strongly and less densely so. Head flattened between moderately large and convex eyes, temples long and converging and frons broad and produced, labrum transverse and curved inwards anteriorly mandibles robust, curved and with a strong internal tooth. Antennae 11-segmented and gradually broadened from a very elongate basal segment, segments 8-11 transverse but not forming a club. Pronotum continuously rounded from a widely sinuate basal margin, surface evenly punctured and smooth, without structure although sometimes indistinctly undulating, lateral margins narrowly bordered. Scutellum large and triangular, lateral margins sinuate and apex perpendicular or nearly so, surface punctures stronger than those on the pronotum and denser than those on the surrounding elytra. Elytra long-oval, almost parallel-sided and continuously curved apically, margins deeply and narrowly explanate and strongly punctured to just before the apex, surface smooth, very finely microsculptured (although this varies and can be quite strong) and evenly punctured, without striae but sometimes with two or three longitudinal finely raised lines. Front tibiae curved internally towards the apex and with a small terminal spur, middle and hind tibiae with a much longer spur on the inner apical angle. Tarsi 5-segmented, the basal pro-tarsomeres lobed in the male and cylindrical in the female.