Padworth Common Emperor Moth Field Trip

The field trip to Padworth Common on Saturday 25th April was another successful and enjoyable outing for the Berkshire Moth Group.

Padworth Common is designated a Local Nature Reserve and Wildlife Heritage Site. It comprises a variety of habitats including heathland, Oak and Pine woodland , ponds and alder woodland gullies across an area of about 30 hectares.

When the trip was originally planned in the winter the target species were to be Emperor Moth (Saturnia pavonia) and the Orange Underwings - Orange Underwing (Archiearis parthenias) and Light Orange Underwing (Archiearis notha). In the event, the season was early with Orange Underwings having being seen nearly a month previous at other sites, so the main target of the trip was agreed to be the Emperor Moth with eyes peeled for Orange Underwings more in hope than expectation.

After a morning of unsettled and changeable weather, the group were pleased to be greeted by sunshine upon arrival at the assembly location.

Les showed some moths from the previous night's trapping from his garden including a Lime Hawk-moth and a Mullein Moth and then the group set off across the Common led by trip leader Grahame. Initially, all was quiet moth-wise but other fauna including a deer, rabbit and common lizard and a few butterflies added to the interest as the group enjoyed chatting while strolling the Common.

Some moths were soon seen flying and once netted they were identified as Common Heath.

Having headed upwind and selected a suitable location, Mark produced an unmated female Emperor Moth which was placed in a freestanding netting cage for the purpose of assembling male Emperor Moths. The breeze quickly encouraged the female to "call" by extruding her pheromone-producing organ. A male was on the scene within 30 seconds! After observing its behaviour for a while the male was contained and placed in the shade. Within only a few minutes a second male had arrived. Success already!

The female was moved around the Common to three further locations and on each occasion a male arrived very quickly.

The birch trees were scanned for Orange Underwings but without luck. There was one possible sighting but it was not possible to confirm it.

Meanwhile, Roger, armed with a saw, took samples of two-year-old birch stumps which showed the characteristic signs of occupancy by the White-barred Clearwing (Synanthedon spheciformis). These will be placed into damp sand in the hope that they may contain pupa.

Grahame then led the group back to his house, which borders the Common, for tea and cakes which was very much appreciated by all. While there, the female Emperor Moth was placed in the back garden in her cage where she attracted two more male Emperors - a first for Grahame's garden.