SUFFOLK DIPTERA CHECKLIST
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Hoverflies are probably the family of flies that are most familiar to the general naturalist. Their appeal lies in the fact that apart from being in the most part rather attractive insects they are frequently encountered in gardens and urban areas as well as in the countryside. They may not garner as much attention as butterflies, moths or dragonflies, but the current interest in pollinators means they have been gaining a higher profile than once was the case. Some recorders are just happy to recognise the commoner and more obvious species without taking specimens, while there are plenty of taxonomic challenges for those who wish to take their interest a stage further. Indeed, for many an interest in hoverflies is a stepping stone to further study of the fascinating world of dipterology. Nowadays the study of hoverflies is much aided by the excellent, field guide by Ball & Morris (2015), and identification keys provided by Stubbs & Drake (1996). The Dipterists Forum Hoverfly Recording Scheme host a Facebook group, which as well as providing a simple way of adding records to the recording scheme database, means that photographic images of hoverflies can be posted online allowing identifications to be made or confirmed. Although, hoverflies are the most studied and recorded family of flies in Suffolk, with about 180 of the 280 British species known from the county, new species continue to be added to the Suffolk checklist. These can be of species that have recently arrived in the country by natural migration from continental Europe or by accidental introductions, or they can be hoverflies that are considered long standing native British species - but because of their rarity have previously not been seen in the county. In the past year I have been made aware of two species of hoverfly that are new to Suffolk; one is a relatively recent arrival into Britain, probably brought in with imported plants, and the other a scarce native hoverfly hitherto not recorded from Suffolk. During the summer Paul Oldfield sent me a record of Cheilosia caerulescens (Meigen, 1822) which he had photographed in his garden in Felixstowe. At the time this was thought to be the first record of this species from Suffolk, but the SBIS database has an earlier 2020 record by Allan King from his Ipswich garden. C. caerulescens is a recent British colonist that was first recorded in 2006 from Surrey (Collins & Halstead, 2008). Following the records from Surrey and another group of sightings in Bedfordshire (probably a case of multiple introduction) C. caerulescens has spread widely across southern England and as far north as Derbyshire. The larvae mine the leaves of non-native houseleeks, mainly Sempervivium tectorum L. but Cheilosia caerulescens Trans. Suffolk Nat. Soc. 57 (2021)
Paul Oldfield
DIPTERA REPORT 2021 PETER VINCENT