SCRAPTIIDAE | uk beetles

SCRAPTIIDAE Gistel, 1848

False Flower Beetles

Anaspis includes some of the most common british beetles, and are abundant throughout spring and summer on flowers and other vegetation. Scraptia are less common saproxylic species.

POLYPHAGA Emery, 1886

TENEBRIONOIDEA Latreille, 1802

2-4.4mm

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Introduction

This is a cosmopolitan family of about 400 species of 30 genera divided into 2 subfamilies, Scraptiinae Mulsant, 1856 and Anaspidinae Mulsant, 1856, and various tribes although the classification has changed over the years; Scraptiinae has often been considered either as a group within the Melandryidae or as a distinct family, and Anaspidinae was formerly included in Mordellidae due to a superficial similarity in overall morphology. Each of the subfamilies are dominated by a single large genus which, together, typify the family as a whole; Scraptia Latreille, 1807 and Anaspis Geoffroy, 1762, but beyond this each is divided into several tribes. Of the Scraptiinae, Allopodini Mulsant, 1856 includes 3 genera, about 10 species and is restricted to north and Central America. Scraptiini Mulsant, 1856 is the largest tribe with 14 genera and is virtually cosmopolitan although, beyond Scraptia, they tend to be of restricted distribution e.g. Trotoma Kiesenwetter, 1851 (8 spp.) and Trotommidea Reitter, 1883 (3 spp.) from North Africa, Nothotelus Broun, 1914 (3 spp.) and the monotypic Phytilea Broun, 1893 from New Zealand, Canifa Leconte, 1866 (10 spp.) from the New World, and Biophida Pascoe, 1860 (18 spp.) from Africa while the monotypic Xylophilostenus Lea, 1917 occurs in Tasmania. Scraptia is a worldwide genus of about 160 species with the greatest diversity in warmer regions; only 2 occur in North America and 9 in Europe of which 3 have been recorded from the UK. Anaspidinae is divided into 4 tribes with the majority of species included in Anaspis. The monogeneric Anaspimordini Fransiscolo, 1954 includes 2 species from Tanzania and Belgium Congo and the monotypic Menuthianaspidini Fransiscolo, 1972 is from Madagascar. Pentariini Fransiscolo, 1954 includes 9 genera and is almost cosmopolitan with some predominantly New World genera e.g. Diclidia Leconte, 1862 and some restricted to the Old World e.g. the mostly Palaearctic Ectasiocnemis Fransiscolo, 1956. Anaspidini includes a few small genera e.g. the monotypic Striganaspis Ermisch, 1950 and Zioanaspis Fransiscolo, 1994 from Africa and Akentra Fransiscolo, 1954 with 4 species from India and Africa, but the majority of species are included in Anaspis Geoffroy, 1762, a widespread genus with the greatest diversity in Palaearctic and African regions but, with the exception of A. rufilabris (Gyllenhal, 1827) which has been introduced to New Zealand, absent from Australasia; 13 species have been recorded from the United States while the European fauna includes about 70 species, of a total scraptid fauna of just over 100 species, of which 14 extend to the UK.

Description

Our UK list includes only 14 species of 2 genera, but is representative of the family as a whole. They are small, 2.5-5.5mm, delicate and mostly rather shiny and drab beetles, black, brown, red or yellow though often bicoloured and maculate, with fine pubescence. The form is characteristically elongate-oval and moderately flattened to convex, the pronotum and elytra are continuous in outline and the head has a transverse basal ridge and so they are superficially similar to Mordellids but they lack the produced and spine-like pygidium of that family. Head convex with large and strongly emarginate eyes, short to medium length antennae inserted anterior to the eyes, and 4-segmented maxillary palpi which have the terminal segment expanded; triangular to securiform, Antennae 11-segmented with the basal segments elongate and narrow, the remainder variously moniliform, filiform or weakly serrate. In life the head is often deflexed in front of and under the prothorax, partly covering the anterior coxae. Pronotum quadrate to transverse; flat to moderately convex, with rounded lateral and anterior margins and a variously sinuate basal margin which is often produced in front of the scutellum, surface smooth and finely punctured or microsculptured, lacking major sculpture but sometimes with weakly developed basal depressions. Scutellum usually large and obvious, triangular to broadly tapering and truncate. Elytra long and weakly rounded or parallel-sided in outline, without prominent shoulders and usually separately rounded apically, without striae although there may be distinct rows of punctures towards the lateral margins, and with well-developed epipleura, at least in the basal half. Legs long and rather robust, especially the mid and hind legs, femora and tibiae long and flattened (Anaspis) or rounded (Scraptia). Tarsi 5-5-4, with long and narrow segments, especially hind tarsi, not obviously lobed or expanded although in many the pro-tarsi are dimorphic with the male having some segments widened, claws smooth and generally lacking a basal tooth. Identification can be very difficult and older works are unreliable, there is a temptation to name specimens in the field from the overall colour but many species occur in several colour forms and there are several all dark species and so this is generally unreliable, critical identification relies on sexing specimens first; as well as tarsal dimorphism most males have appendages on the terminal abdominal sternites and some have modified middle tibiae, once sexed specimens are generally straightforward to identify using colour etc. and, especially, a critical examination of the antennal segments. Very fortunately our UK fauna can be dealt with using the recent Royal Society Handbook by Brian Levey.

Larvae are long and slender, flattened to subcylindrical and weakly sclerotized with well-developed and 5-segmented legs, those of Anaspis posses a pair of simple urogomphi with a groove between them while those of Scraptia have a single rounded apical projection which may serve as a defence against predators as it can be re-grown if detached. Larval biology is only poorly understood but those of many temperate species occur under bark, among decaying wood or are associated with various fungal fruiting bodies, those of Anaspis pulicaria Costa, A., 1854 may develop in the stems of woody plants. Some exotic species have been found among lichens, leaf-litter or in bird nests.

Ecology

Species of Anaspis are diurnal, they are short-lived and have a short season during spring and early summer but may very abundant, they often occur on umbels and other flowers in large numbers where they may be observed mating, they fly readily but are easily sampled by sweeping or by tapping flowers into a net; this will also be effective at night when they tend to remain in the flowers. Sweeping foliage generally will also produce them and they are likely to turn up in flight-interception and yellow water traps. Adult Scraptia are also short lived but these will generally need to be searched for among decaying wood or around rot-holes of a range of broadleaf trees although they have been recorded from Crataegus blossom. Larvae develop among soft decaying xylem in old Oak, Beech and Hawthorne etc.