Apion haematodes Kirby, 1808

This western Palaearctic species is generally abundant throughout Europe and across North Africa, extending east into Asia Minor and central Russia, and north into Fennoscandia and the UK. Here it is locally common and often abundant throughout England, Wales and Ireland, becoming less so and more local to the far north of Scotland including the Western Isles, Orkney and Shetland. Typical habitats are areas of dry grassland, moorland and wasteland, often on light sandy or chalky soils or in dry peaty areas, but they also occur on roadsides and agricultural borders etc. where the host plants are common. The species is very narrowly oligophagous on various Polygonaceae; the usual host is sheep’s sorrel (Rumex acetosella L.) but common sorrel (R. acetosa L.) and herb patience (R. patientia L.) have also been recorded hosting the species. Adults are present throughout the year; they overwinter in the soil or among litter near to host plants and become active during the first warm days of March or April although specimens may occasionally occur in samples or by sweeping during the winter, and remain active through the summer. Mating occurs after a period of feeding during the spring and continues into early summer, females oviposit in stems or roots near the ground and larvae develop in the upper, thicker parts of roots; they tunnel through root tissue but do not form galls and contrary to some accounts, do not develop in petioles or leaf veins. Development is rapid; pupation occurs within the roots and new generation adults occur from late June. Sweeping suitable foliage during the summer is the easiest way to sample this species and in certain years, when huge local populations may occur, a single sweep may produce hundreds of adults.