Brown roofs for invertebrates
HEMIPTERA Stictopleurus abutilon (a rhopalid bug): this is a large pale greenish brown bug
found in dry open habitats. There were old confirmed records for Kent, Surrey, Hampshire and
Dorset, but until recently it was believed to be extinct in Britain, but was recorded from Essex in
1996 and from several locations in the south of England (Kirby 1997). In the last few years it has
been recorded widely in warm open flower rich grassland in the southeast, presumably in response
to climate change, on 'waste ground' or other unmanaged and sporadically disturbed habitat, but
the species seems far less common than Stictopleurus punctatonervosus.
HEMIPTERA Stictopleurus punctatonervosus (a rhopalid bug): this is a very similar bug to the
preceeding species, also found in dry open habitats. There were nineteenth century records of this
species from Surrey and Sussex, but until recently it was believed to be extinct in Britain (Bowdrey
1999). It is now recorded widely in warm open flower rich grassland in the southeast, presumably in
response to climate change, on 'waste ground' or other unmanaged and sporadically disturbed habitat.
HYMENOPTERA Andrena pilipes (=spectabilis) (a mining bee): this is a Nationally Scarce
mining bee in the carbonaria group, host to the Nationally Rare (RDB3) cuckoo bee Nomada
fulvicornis. It is mainly coastal in distribution, and is widespread along the East Thames Corridor.
It occurs in sandy areas of heathland, waste ground and sandpits, coastal grassland and landslips.
The bec requires patches of bare, sandy soil or short turf in warm, sunny situations for nesting. The
first brood is reported to collect pollen from Salix, Primus and Brassica, whilst the second brood
favours Rubus and thistles (Falk 1991).
HYMENOPTERA Bombus humilis (Brown-banded Carder Bee): this bumblebee is a UKBAP
species on the basis of major declines across Britain, especially inland. Bumblebee populations
appear to operate at a landscape scale and it is probable that viable individual populations require
minimum ranges of between ten to twenty sq. km of good matrix habitat within farmland (Edwards
1998). The East Thames Corridor region currently supports one of the most important remaining
metapopulations in the UK, but many sites are already lost or under direct threat of development.
The bumblebee occurs at least as far into London as the docklands, and suitable brown roof habitat
is almost certainly the only way its extinction here might be prevented.
Bombus humilis appeal's to be more able to utilise suitable small areas within a landscape than
Shrill Carder Bee, another bumblebee with a nationally important metapopulation in the region.
Observations suggest that large patches of flowers are used more frequently and are much more
important than widely distributed resources. Observations also indicate that the availability of suitable
forage (nectar and pollen) sources throughout the season from May to September is crucial. These
resources need to be provided by an abundance of specific key forage sources, all of which significantly
have very long flowering seasons as well as long corolla tubes that correspond to the long tongues of
the bumblebees. Important plant species used in early summer by queens include Fodder Vetch, Red
Clover Trifolium pratense and Broad-leaved Everlasting-pea Lathyrus latifolius. Workers forage on
the flowers of species such as bird's-foot trefoils Lotus spp., clovers, Black Horehound Ballota nigra.
Lucerne Medicago sativa and Red Bartsia Odondites verna (Harvey 2000b, Harvey 2001a).
However nesting and over wintering habitat are also obviously essential. These are not well
understood for B. humilis, and it although nesting may occur on brown roofs in open tall flower-
rich grassland, over wintering sites may be more difficult to accommodate.
HYMENOPTERA Ceratina cyanea (Blue Carpenter Bee): the Blue Carpenter Bee is a Red Data
Book (RDB3) bee confined to southern England, with most recent records from West Sussex and
Essex Naturalist (New Series) 21 (2004)
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