To the amateur naturalist moths can be a fascinating subject to study. They are an incredibly diverse group with over 2,500 different species recorded in the UK (71 species of butterfly recorded in the UK seems meagre in comparison!). Though often dismissed as brown and drab, many moths are quite the opposite, showing just as brightly coloured wings and a great deal more variance in terms of shape and body size than butterflies.
What makes moths such an interesting group to study? Well, for me it is the fact that a large diversity of species can be observed in a small area, such as an ordinary back garden. The most effective way to assess the moth population of a site is to run a ‘light trap’ overnight. This technique attracts moths in large numbers by exploiting their tendency to become disorientated by bright light. Moths enter the trap where they rest on egg trays and are unable to get out. The next morning, the ‘catch’ can be studied and once identified and recorded the moths are released unharmed. Using this method to date I have recorded over 400 species of moths in my north Cambridge garden.
|Actinic Mercury Vapour
There are many spectacular and beautiful moths to be found in the Cambridge study area. The most impressive group are the Hawkmoths, which are medium to large moths, often brightly coloured. There are seven species which can be regularly recorded in Cambridge city which include the enormous Privet Hawkmoth (as large as a mouse!), bright pink Elephant Hawkmoth and stunning Eyed Hawkmoth. Late May to July is the best time to look for Hawkmoths and this year has been particularly good with a larger than normal number recorded.
|Elephant Hawkmoth||Eyed Hawkmoth||Buff Tip (upside down!)|
On an average night at this time of year one could expect to catch at least 50 species, even in urban areas. Intriguing moths such as the Buff Tip (which perfectly mimics a twig) as well as the striking Leopard Moth and Phoenix Moth are all common in the city centre.
Warmer nights tend to be the most productive, and with the ongoing heat wave which Cambridge has been experiencing, it has resulted in a bumper spell for moth recording. The night of July 7th produced a particularly large catch in my garden, with upward of 450 moths consisting of 120 different species!
With every trapping session there is always the chance of catching something rare. Trapping during the warm weather and southerly winds this summer has been rewarding with several unusual species recorded in my garden. These have included the Red Data Book species Toadflax Brocade (only a handful of Cambridgeshire records), the scarce immigrant Dewick’s Plusia and one of my favourites – the Scallop Shell, which is normally confined to damp woodland.