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The Fauna Of Tunbridge Wells And Rusthall Commons - Part 7

along with containers for storing food. Her first offspring are workers, sterile females which assist in the development of the colony and take over the work of gathering nectar and pollen. The Buff-tailed (Bombus terrestris), White-tailed (B. lucorum), Garden (B. hortorum), Early (B. pratorum) and Red-tailed (B. lapidarius) Bumblebee are all familiar visitors to flowers on the Commons, as is the distinctive brown Common Carder Bee (B. pascuorum). Lone queens seen flying low in the early months of the year are engaged in their search for suitable nest sites. Honey-bees are regularly seen on the Commons too, but these are visitors from domestic hives. Social wasps recorded on the Commons comprise the two familiar urban species Vespula vulgaris and V. germanica, along with the Tree Wasp (Dolichovespula sylvestris) and two related species which have recently colonized southern Britain from the Continent (D. media and D. saxonica).

The other social insects found on the Commons are the ants, one of which contributes a major feature to the landscape in the form of the prominent earthen mounds to be seen in areas of acid grassland such as that around Highbury. These are constructed by the Yellow Meadow Ant (Lasius flavus), and may be many decades old. The ants themselves remain below the surface and are unlikely to be seen unless one of their nests is disturbed. Sections of these old nest mounds are sometimes occupied by colonies of the brown ant Myrmica scabrinodis. Unlike the meadow ant, this and its relative M. ruginodis are commonly seen actively foraging, often high up on grassland vegetation. Most widespread of all, found both in open spots and in woodland, are the subterranean nesting Lasius niger, the familiar garden black ant, and the larger long-legged Formica fusca. It is the latter two species whose winged females are most likely to be noticed by the general public as swarms of ‘flying ants’ on hot days in high summer. These are newly emerged queens engaged, along with the much smaller males, in their annual synchronised courtship flight, after which they shed their wings to retreat underground as founders of new colonies.

Numerous as they are, bees, wasps and ants form only part of Britain’s largest order of insects, the Hymenoptera. The other members of the order are also well represented on the Commons, but most are small and inconspicuous. Several species of sawflies, however, are quite large and brightly coloured, and may be seen visiting flowers. Their name derives from the females' saw-like ovipositor, used to insert their eggs within plant tissues. Many sawflies have larvae which feed openly on leaves and resemble the caterpillars of moths and butterflies, but others develop inside galls which their foodplant produces in response to the larva’s presence. Galls, which take distinctive forms according to the insect species that causes them, are also produced by the Cynipidae or gall wasps, and in this case they are much easier to identify than the minute insects themselves. Many cynipid galls can be found on the Commons, including the familiar oak-apple, the marble and spangle galls, also on oak, and the robin’s pincushion on rose. Another important group of Hymenoptera are the ichneumon flies, whose larvae feed as parasites inside caterpillars or other insects. The females are generally armed with a conspicuous ovipositor, and some of the larger species are brightly patterned in yellow and black or red and black. They are most often seen running about on sunlit foliage, or flying around bushes and low vegetation in search of suitable hosts.

Translucent Hoverfly

Among the most prominent of the two-winged flies or Diptera are the hoverflies, named for their aerial skills which allow them to hang motionless in mid-air. They are also effective mimics of bees and wasps. Young birds soon learn that insects patterned in yellow and black or red and black are either distasteful or capable of stinging, and many harmless insects gain protection by having a similar appearance. Around sixty species of hoverflies are to be found on the Commons, most of them visiting flowers along with their models. The largest British species belong to the genus Volucella, and the impressive V. zonaria, a migrant species, has occasionally been recorded on the Commons. More likely to be seen is V. pellucens, which regularly hovers along woodland paths; its black and white colouration, unusual among hoverflies, is shared by the smaller spring-flying Leucozona lucorum. The slender-bodied members of the genus Xylota are to be seen on sunlit leaves rather than flowers: they include the red-banded X. segnis and the beautiful gold-banded X. sylvarum. The droneflies, of which six species are found on the Commons, are bee mimics, and include the very common Eristalis tenax, which is notable for hibernating as an adult and appearing on sunny days all through the year. This species and the similar E. pertinax resemble honey-bees, while E. intricarius is a furry bumblebee mimic. Many of the Commons’ hoverflies have variations on the standard wasp pattern of yellow and black stripes. These include the common Syrphus ribesii, the distinctive Helophilus pendulus with vertical stripes on the thorax as well as the usual horizontal ones on the abdomen, and the latter’s larger and scarcer relative H. trivittatus.



Page last updated: 22/01/07