NOTES ON SOME SUFFOLK MOTHS, 2003
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COMMENTS AND NOTES ON SOME SUFFOLK MOTHS IN 2003 TONY PRICHARD For most moth recorders this year will go down as one of the more memorable following a period of rather mediocre years. After a rather slow start with a spring dominated by cold nights conditions improved greatly during the summer. The period of dry warm weather from June through to September proved very productive for moth recording in terms of suitable nights for moth trapping and the numbers of moths appearing at light. The year was particularly notable for the number of migrant species recorded throughout the county. The long dry summer had an adverse effect on trees and shrubs in late summer/early autumn with shrivelled leaves being a frequent sight. The full effect of this lowered quality of foodplant on any larvae trying to feed at this time of year and how it will affect subsequent adult numbers will need to wait till next year, but numbers of larvae being found at this time were particularly low in comparison with normal years. After such a fine summer moth recording for the year was rather curtailed by a poor autumn and winter. Work on surveying the scarcer moth fauna of the county started early in 2003 (or to be precise in mid-December 2002) when members of the Suffolk Moth Group were asked by Butterfly Conservation to carry out surveying for larvae of Noctua orbona (Hufnagel) Lunar Yellow Underwing in the Sandlings. This moth has in recent years undergone a severe decline in its distribution across the country and the heathlands of the Brecks were thought to be its remaining stronghold in the country with a few scattered colonies elsewhere. The larvae feed at night on warmer nights during the winter and spring on various fine-leaved grasses (Festuca, Agrostis, Deschampsia) associated with acid heathland. Surveying for larvae consists of searching in torchlight at night, when the larvae are readily detectable as they climb up and rest on dried-up grass stems. Some recent records at light seemed to indicate the possibility of populations of the moth occurring in the Sandlings area and that surveying in this area would prove worthwhile. Surveying started in midDecember 2002 and continued into April 2003 at suitable sites in Rendlesham Forest, Tunstall Forest and other heathland sites up to Minsmere and proved very successful in the main. The species was found to occur at most sites surveyed, where suitable habitat and foodplant occurred, and it would appear that the Sandlings area supports a sizeable population of the species. The large numbers of larvae found at many sites compared with the much smaller number of light trap records from the area may suggest that this species could be reluctant to come to light. Future assessment of the status of this species may be better determined using night-time searching for larvae rather than relying on light trap records that may give an imprecise assessment of its status. The larvae of Xestia rhomboidea (Esper) Square-spotted Clay have previously eluded discovery in the wild. Nationally the moth is rather restricted in its distribution having undergone a dramatic decline in its distribution with the East Anglia region seeming to be the area where the moth remains most prevalent. Records of the moth appearing at light in Suffolk show concentrations in the Breckland and Sandlings areas (the species tends to be associated with lighter soils) and locally it would appear not to be that rare Trans. Suffolk Nat. Soc. 40 (2004)