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The Fauna Of Tunbridge Wells And Rusthall Commons - Part 4

The lemon yellow males of the Brimstone are a familiar sight on the Commons in early spring. They hibernate as adults and generally appear at the same time as the Small Tortoiseshell, Peacock and Comma, ranging over a wide area. The Large White and Small White are also highly mobile species, their British populations regularly augmented by migration across the Channel. Both are frequently seen on the Commons, and the latter may sometimes breed there on wild members of the cabbage family. The familiar Red Admiral, patterned in white and scarlet on black, is similar to the Small Tortoiseshell and Peacock in its habits and also breeds on nettles, but as it rarely survives the English winter it is not a permanent resident. Its population too is reinforced each year by migrants. The salmon pink Painted Lady is a much less regular migrant, although in favourable summers it has been recorded on the Commons in considerable numbers.

Day-flying moths can often be confused with butterflies, and some are surprisingly brightly coloured. A characteristically early species is the Orange Underwing, which flies in March and April, sunning itself with outspread wings on the ground in the wider footpaths or feeding at sallow catkins. May sees the appearance of the Small Yellow Underwing, a grassland species. The brilliant red and black Cinnabar moth is occasionally seen on the Commons, as is its distinctive orange and black striped caterpillar feeding on ragwort. In high summer, the Six-spot Burnet can sometimes be found flying in open grassland on both Commons, together with various butterflies. This moth has a similar colour scheme to the Cinnabar, but it is distinguished by the array of red spots on a forewing that is black with metallic reflections. These patterns are examples of warning colouration, which vertebrate predators learn to associate with creatures that are distasteful. The Silver Y is a much duller coloured insect, although its intricate pattern incorporating the metallic mark from which it takes its name is attractive on close inspection. Although sharing the nocturnal flight pattern of the majority of moths, the Silver Y is often active during the day as well, feeding at heather and other flowers. The metallic Green Longhorn and its relatives are much smaller insects, but the males with their astonishingly long antennae make themselves conspicuous in spring by flying in dancing swarms around sunlit trees and bushes.

The majority of the moths which live and breed on the Commons are purely nocturnal, and are therefore rarely or never seen by the general public. However, the use of a light trap at a number of locations, mainly on Tunbridge Wells Common, on several nights through 1992 produced a list of over one hundred and fifty species. It is certain that further and more regular trapping would increase the list considerably, and it is likely that most of the six hundred or so moth species recorded from Tunbridge Wells in modern times could be found on the Commons. Although moths have a reputation for being drab and nondescript insects, they are actually extremely diverse in colour and pattern, and a number of those recorded from the Commons are visually impressive creatures. Among the largest are the hawk moths, including the delicately patterned green Lime Hawk, the Poplar Hawk, and the brilliantly coloured pink and green Elephant Hawk. The latter takes its name from the resemblance of its caterpillar, found on willowherb, to an elephant’s trunk. As its name suggests, the White Ermine is pure white with scattered black spots, while its relative, the Buff Ermine, has a similar pattern but different ground colour. The Buff-tip has a remarkable resemblance to a broken silver birch twig when its wings are folded, while the relateallow Prominent and Lesser Swallow Prominent have streamlined wings with an elegant white and brown pattern. The Brimstone moth, with bright yellow wings, shares its name with a butterfly, as does the Swallow-tailed, a large broad-winged insect of a delicate yellowish shade. Other strikingly coloured species include the Peach Blossom, the Light Emerald, and the bright metallic Burnished Brass.

Brighton Lake, Fir Tree Pond and Bracken Cottage Pond (on Tunbridge Wells Common) and the Marl Pits (on Rusthall Common) all support breeding colonies of dragonflies, although the larger spring-fed Brighton Lake is the most productive. The early stages or nymphs of these insects live as predators underwater, and adult females can often be seen laying their eggs by dipping the tip of their abdomen into the water. Regular breeding species include a number of damselflies, the smaller members of the dragonfly order, of which the most numerous are the distinctive Large Red, first to appear in spring, the Blue-tailed, and the Common Blue and Azure, which resemble each other very closely. The scarce White-legged Damselfly, creamy white in colour, is less often seen. Damselflies fly together, often in large numbers, as does the medium-sized.

Page last updated: 22/01/07