T H E S U F F O L K B U T T E R F L Y S U R V E Y 1983 HOWARD MENDEL a n d STEVE PIOTROWSKI
The 1983 season, the first of the Survey, made a promising start early in April, warm weather bringing out the hibernating species—Brimstone, Comma, Small Tortoiseshell and Peacock. However a sudden change and several cold wet weeks put everything back, and severely affected numbers of Small Tortoiseshell, in particular, for the rest of the year. The effects of the weather were not all bad. The Orange Tip had a very long season, lasting from early May to the end of June, and Meadow Brown, Ringlet, Wall and Gatekeeper appeared to be more numerous than usual. Other common species were Large, Small and Green-veined Whites, Small Copper, Small Heath, Common Blue, and Red Admiral. Interestingly, there were some March and April records of this latter species, indicating that at least some individuals managed to survive the winter in hibernation. The Red Admiral is not usually considered hardy enough to survive our winters, and must re-colonise Britain each year, as must the less common and less predictable Painted Lady. The biggest surprise of the year was the huge immigration of Clouded Yellows. The early arrivals produced a strong first brood late in July, and fresh specimens late in September indicate that there may well have been a second brood. The map below shows how well distributed this species was in Suffolk, and 1983, if not the best year ever for Clouded Yellows must certainly be the best recorded year! Large and Small Skippers were fairly common and widespread, as was the Holly Blue, which first made its appearance in April, long before the Common Blues were seen in late May and early June. The Essex Skipper, though common in the south-east of the County and the Breckland was decidedly scarce or absent elsewhere. The distributions of Green Hairstreak and Grayling correlate well with the Sandlings and the Breckland, while the Silver-studded Blue would seem now to be confined to a few of the better Sandling areas. The Speckled Wood continues to extend its ränge from its headquarters in the breck forest areas, and several as yet unconfirmed coastal records are of particular interest. In contrast the Dingy Skipper and White Admiral are in decline and very rare in the County, only hanging on in a few coniferous forest areas. The White Admiral was thought to be extinct in Suffolk, and so the discovery of several healthy colonies was a high point of the Survey. The White-letter Hairstreak is decidedly uncommon, suffering no doubt from the effect Dutch Elm Disease has had on the larval food plant, but the Purple Hairstreak is still widespread, though local. The Brown Argus, with the exception of a few isolated colonies, is now a species of the Breckland and from records received by Ist March, brings the number of species recorded during the course of the Survey to thirty-one. We should like to thank Suffolk Naturalists for sending us an enormous number of records, and look forward to receiving even more at the end of
Trans. Suffolk Nat. Soc. 20
THE S U F F O L K B U T T E R F L Y S U R V E Y
31
1983/1984
SUFFOLK WATSONIAN VICE- COUNTIES
Clouded Yellow
25 E..t Suflom
26 Wnt SuftaJk
Colias croceus
Watsonian vic*-county bowndaft«» wtMr* *** th«M dtflvr (romftdminittrativ«boundart««
this, the final year of the Survey. The results will form the basis of the 'Atlas and History of Suffolk Butterflies', which should be ready for publication early in 1985. Howard Mendel & Steve Piotrowski, The Suffolk Biological Records Centre, The Museum, High Street, Ipswich, IP1 3QH.
Trans. Suffolk Nat. Soc. 20