Ampedus balteatus (Linnaeus, 1758)
This very widespread and generally common species occurs from lowland to mountain altitudes throughout most of the Palaearctic region; in Europe from France south to northern Italy and Bulgaria, north to the UK and above the Arctic Circle in Fennoscandia, and extending east through Kazakhstan and Russia to northern Mongolia and eastern China. Here it is locally common across Wales and southern and central England, more local and sporadic north to the Scottish border and there are isolated groups of records in the northern Scottish Highlands. The typical habitats are coniferous and mixed woodland and parkland but they also occur among isolated groups of trees on moorland and around peat bogs. Adults are active from May until July or August, they are diurnal and may be seen on warm days at rest on foliage or standing or fallen timber, and they also fly well and readily and visit a wide range of flowers. Adults mate early in the season and females oviposit in bark or among soft decaying wood, usually in conifers and especially pine, but also in broadleaf trees, especially birch and oak, but only when these occur in mixed woodland. The predatory larvae, which also consume decaying plant material, develop under loose bark on dead or dying trees and stumps or among soft decaying xylem and have also been found at the base of trunks among accumulated soil and wood fragments. They develop through the summer, overwinter in situ and complete their development over the following summer although at higher latitudes the larval stage may take longer to complete. Pupation occurs in a cell under loose bark or among rotting wood in late July and August, and adults are fully formed by the autumn but they remain in the pupal cell until the following spring when they emerge and become active when the temperature exceeds ten degrees Celsius. Adults are easily sampled early in the year by searching among loose bark, later in the spring they may be swept from tree foliage, especially from pine, or various flowers or spotted resting on timber or fence-posts etc.
This medium sized elaterid is distinctive due to the bicoloured elytra and should not be confused with any other UK species. 7.5-9.0. Head, pronotum and scutellum black, elytra red with the apical third black. Head and pronotum densely and finely punctured, with short dark pubescence which may be, rarely, pale. Antennae black. Pronotum smoothly convex, with a raised keel above the produced posterior angles. Elytra parallel-sided to the apical third then narrowed to a continuously rounded apex striae well-impressed and punctured, interstices weakly convex and finely punctured. Legs black with pale tarsi. Male antennae a little longer than the pronotum, female antennae about as long as the pronotum. Very rarely continental specimens occur with entirely pale elytra.