Brown roofs for invertebrates Species that might benefit There are many examples of invertebrate species that might benefit from suitably designed brown roofs. Some are discussed below: ARACHNIDA Bianor aurocinctus (a jumping spider); most records of Bianor aurocinctus are from the south-eastern part of England, and this Nationally Scarce spider is most frequent in Britain in the East Thames Corridor (Harvey et al. 2002). It is found on dry sparsely vegetated ground in a variety of habitats, but always among short vegetation or in stony areas. ARACHNIDA Zodarion italicum (an ant-eating spider): the centre of distribution in Britain is the East Thames Corridor in south Essex and north Kent (Harvey et al. 2002). This pScarce A species is recorded from only 16 ten-kilometre squares in Britain, and many of its habitats are threatened by development. The spider is strongly associated with dry, warm, sunny open habitats containing a proportion of bare ground. The spider makes an 'igloo'-like retreat and feeds on ants such as the common black ant Lasius niger. DIPTERA Cheilosia velutina (a hoverfly): the larvae of this Nationally Scarce species may mine the stems of Cirsium palustre (Ball & Morris 2000), and adults arc often found at the flowers of white umbels such as Daucus carota. It has been found to be relatively frequent in suitable habitat in the East Thames Corridor, but the species remains poorly known with very few confirmed records, mainly on the eastern side of Britain. DIPTERA Gymnosoma nitens (a parasitic fly): this fly is a Red Data Book parasite on the nationally scarce shieldbug Sciocoris cursitans, a species of dry sandy and calcareous places. Most British records of G nitens arc recent, from waste ground and open unmanaged or sporadically managed grasslands in the East Thames region (Harvey 2002b). Both the fly and its host might benefit from suitably designed and managed brown roofs. Other related tachinids, such as Catharosia pygmaea, known from several brownfield sites in south Essex near the Thames, might also benefit. DIPTERA Triglymus primus (a hoverfly): this Nationally Scarce species is rather scarce and local in south-east Britain from around Dorset and Wiltshire eastwards, and north to about a line between the Mersey and the Humber. The larvae arc aphidophagous, and appear to be specific to the galls induced by Cryptosiphum artimisae. on Artemisia vulgaris. Adults are elusive, but tend to be found visiting flowers such as white umbels or resting on sunny foliage in the sorts of places that Artemisia grows (Ball & Morris 2000). HEMIPTERA Asiraca clavicornis (a planthopper): this Nationally Scarce species has distinctive expanded front legs and antennae. It has a strongly south-eastern distribution, and is quite frequent in some parts of its range, such as in suitable habitat in the East Thames Corridor. It is found low down in dry grassland, including sparse grassland of recent origin on derelict land. HEMIPTERA Lygus pratensis (a capsid bug): this Red Data Book (RDB3) species used to be thought of as a rare woodland ride and edge species. On the continent, though, it has apparently always been a polyphagous species in weedy places, and there has been the occasional British record definitely not connected with old woodland (P. Kirby, pers. comm.). In the last few years, the bug has been recorded in the south-east, Hampshire to Kent to Essex to Berkshire. The scattered old colonies may have spread, or there may have been a secondary wave of continental immigration. 84 Essex Naturalist (New Series) 21 (2004)