Malachius aeneus (Linnaeus, 1758)
Scarlet Malachite Beetle
POLYPHAGA Emery, 1886
CLEROIDEA Latreille, 1802
Malachius Fabricius, 1775
This very widespread species occurs from lowland to low mountain altitudes (1150m) throughout Europe north to the Arctic Circle and east through Asia Minor to Siberia, it is also found all over the Middle East and, following introductions, is widespread in North America and Canada. Across much of this range, especially in Europe, there has been a severe decline in recent decades but it remains locally common in some parts of northern Europe. In the UK there has been a recent and drastic decline in its occurrence, it is now known from only a few sites in Essex, Hertfordshire, Bedfordshire, Surrey, Hampshire and Wiltshire and is listed as a priority species on the UK Biodiversity Action Plan; until the 1930s it was much more widespread with records as far north as Northumberland and extending in the south to Kent and Somerset. It is not clear why the species has become so rare but changes in farming practices, woodland management, water abstraction and habitat fragmentation are thought to have contributed. In the UK adults appear during May and June, on the continent a little later extending into July, they are short-lived, about 3 weeks, and in any given year the season lasts for about a month. They typically occur among long grass in flower meadows or along hedges bordering agricultural land, they are active in bright sun and visit a range of flowers e.g. Ranunculus, Brassicas and cereal ears, feeding upon pollen but they are also known to be predate other insects and their larvae on these flowers. Little is known of the biology but on the continent larvae occur in dry, decaying wood, under bark and in dry rot-holes, and in the UK they have been found under logs, which is typical of the family-in general malachid larvae develop in wood through the summer and then overwinter and pupate in the spring.
Among our UK fauna this species is quite distinct and should be obvious from the colour alone. 6-7mm. Head dark metallic green or blue with yellow mouthparts, pronotum dark metallic with pale anterior angles, elytra metallic green across the base and along the suture, otherwise red. Dorsal surface with fine semi-erect dark pubescence. Appendages dark metallic although the tarsi are often to some extent yellow. Antennae sexually dimorphic, the second and third segments expanded internally in the male.