NOTES AND COMMENTS ON SOME SUFFOLK MOTHS IN 1991 M . R . HALL
In spite of a comparatively late start to the season, following yet another spring when nights were cold, and what seemed an extraordinarily early close in the autumn, moths recorded in Suffolk in 1991 have included a goodly number of rare, exciting and unusual species. A good deal has been added to our knowledge of the present-day status of several of the County's less common moths. As more records are received from an increasing band of recorders, the cyclical pattern of occurrence for many moths, both common and less common, becomes more obvious. Several species continued the apparent rise in both numbers and distribution that had been indicated in the preceeding year or two. Among such species are the golden plusia, Polychrysia moneta Hb., brick, Agrochola circellaris Hufn., bird's wing, Dypterygia scabriuscula Linn., garden dart, Euxoa nigricans Linn., treble bar, Aplocera plagiataplagiata Linn, and probably to a lesser extent the treble brown spot, Idaea trigeminata Haw., all of which were much less obvious four or five years ago. The treble brown spot is a species that has been steadily increasing in the last few years, as is the golden plusia which is a garden species with the larvae feeding on Monkshood and cultivated species of Delphinium. As would be expected if such cyclical changes are the norm, these increasing species are balanced by others that seem to be declining at the present time. In this group we are finding the large nutmeg, Apamea anceps D. & S., white ermine, Spilosoma lubricipeda Linn., and the dotted rustic, Rhyacia simulans Hufn., which had a really noticeable surge in 1986/87 but has been more-or-less absent from records since. It was recorded from Barrow (AP) in 1991, as was the fern, Horisme tersata D. & S. This is a species with a very specific larval foodplant, Travellers Joy, and it is almost certainly much more widespread in the chalky parts of the county than present-day records would indicate. Another widespread species, the maple prominent, Ptilodontella cucullina D. & S., has generally occurred at low densities and never been regarded as a 'common moth'. In 1991 there have been many more records than usual, from right across the county, and a similar increase in records has also been noted in Norfolk. There were also many records of migrants received in 1991 - the humming-bird hawk-moth, Macroglossum stellatarum Linn, was reported from many places (with one individual recorded for several days at Aldeburgh (FS)) as was the convolvulus hawk-moth, Agrius convolvuli Linn, (with the larva being noticed at Southwold (JW)). Another record of hawk-moth larvae was received from Ixworth (JC) where the very distintive elephant hawk-moth caterpillars on Fuchsias caused comment. Vine's rustic, Hoplodrina ambigua D. & S., was noted by many recorders across the county (AW, MH, RSL, NO, AP), and although it is regarded as a resident species
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inhabiting waste places and gardens (particularly in East Anglia) this flush of observations would tend to support its immigrant status as well. Of particular note during the year was the appearance of the shaded fanfoot, Herminia tarsicrinalis Knoch, at light at Minsmere (GW). This is another Suffolk Station for a species only comparatively recently resident in Britain and still to be found, as a breeding species, only in Suffolk and Norfolk. This and the re-appearance of some of the scarcer Breckland species were probably the highlights of the year. The tawny wave, Scopula rubiginata Hufn., was recorded at Martlesham (HM), and re-appeared at a couple of sites in the Brecks near Icklingham. At one of these sites the marbled clover, Heliothis viriplace Hufn., bordered gothic, Heliophobus reticulala marginosa Haw., cream-spot tiger, Arctia villica britannica Ob. and grey carpet, Lithostege griseata D. & S., were also recorded. The grey carpet, which in recent years has only been sporadically recorded from the King's Forest area (RE), was noted in appreciable numbers at the Centre Parcs site at Elveden. The soil disturbance when construction work was in progress had allowed the dormant seeds of Flixweed, Descurainia sophia, to germinate in profusion. This banquet of the preferred larval foodplant had presumably attracted comparatively local female grey carpet moths and the resultant localised population 'explosion' was noticed in 1991. The hรถrnet moth, Sesia apiformis Cl., one of our day Aying clearwings that mimic various Hymenoptera, was recorded in the King's Forest (RE) and initial surveying in Bradfield Woods (RE) revealed the day-flying orange underwing, Archiearis parthenias Linn., and the yellow horned, Achlya flavicornis galbanus Tutt, both of which are early-season species. The orange moth, Angeronaprunaria Linn., was again recorded at Weston (NM) and, in 1991, also in Bradfield Woods (RE) and at Ellough (MP). At this Ellough airfield site both the brown-veined wainscot, Archanara dissoluta Treit., and the crescent, Celaena leucostigma Hb., were recorded. These species are usually regarded as wetland moths and such a sighting highlights both the mobility and versatility of many adult moths. The cresent was also recorded from Icklingham (MH) in Company with the white colon, Sideridis albicolon Hb., and the yellow belle, Aspitates ochrearia Rossi - typical Breckland species. Both these latter species were also recorded from the Landguard Bird Observatory (NO) at Felixstowe, as were the feathered brindle, Aporophyla australis pascuea H. & W., and three other species that are associated with coastal sites (in Suffolk) - the mullein wave, Scopula marginepunctata Goeze, the feathered ranunculus, Euchmichtis lichenea Hb. and the brown-tail, Euproctis chrysorrhoea Linn. The feathered brindle also occurred a little further up the coast at Hollesley (RSL) together with the cream-spot tiger and a species not usually associated with such a site, the mere wainscoat, Photedes fluxa Hb. This is another species often associated with damp habitats, where the larvae feed internally in the stems of Smallreed, but it was also recorded from Emily's Wood at Brandon (RE). The old lady, Mormo maura Linn., a widespread moth that is particularly poorly recorded because it infrequently comes to light and is more usually attracted by sugaring (when such Victorian methods are still practiced), was also noted Trans. Suffolk Nat. Soc. 28 (1992)
NOTES AND COMMENTS ON SOME SUFFOLK MOTHS IN 1 9 9 1
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at Hollesley. The feathered ranunculus was also recorded from Holbrook (REd). As in previous years, one or two under-recorded species were 'discovered' by specifically searching for the larvae. In April the heath rustic, Xestia agathina Dup., was recorded on Ling, Calluna vulgaris, at Wortham Ling (MH) and the sloe pug, Chloroclystis chloerata Mab., on Blackthorn blossom from Red Lodge at Freckenham (GH). In May the shore wainscoat, Hythimna litoralis Curt., was confirmed among the Marrams at Walberswick by 'tickling' the sand during a particularly cold and wet afternoon (SW). The benefits of Virtual continuous moth trapping at one place were again typified from Monk's Eleigh (AW) where both the flame carpet, Xanthorhoe designata Hufn., and the red-green carpet, Chloroclysta siterata Hufn., were added to the species list for the site. The buttoned snout, Hypena rostralis Linn., was also recorded at Monk's Eleigh in good numbers with Hollesley (RSL) being added to those places from which this Hop-feeding species is now known. With the larval foodplant so widely distributed throughout the County there must be many more colonies still to be discovered. Another species that is almost certainly much more widely distributed than current records indicate is the knot grass, Acronicta rumicis Linn., which came to light at Barnby (NM). The same site produced records of the treble bar, which is a moth with larvae feeding on St. John's Wort, and the chamomile shark, Cucullia chamomillae D. & S., which, with the larvae feeding on various Mayweeds and Chamomiles, is usually regarded as frequenting cornfields, commons, roadside verges and waste ground. We are very pleased to have received several 'new' records for 1991, both from new recorders and from new sites. In addition to the obvious value of increasing the known distribution for many species they also highlight that there are several species where sufficient recording will probably indicate that they are still as widespread (if not quite so common) as in the days of Claude Morley (1937), and not as threatened as they seem at the moment. Do send copies of all your records, whether from regulär light trapping, specialised survey, or casual observance, to the County Recorder, Arthur Watchman, Onchan, Back Lane, Monks Eleigh, Suffolk, IP7 7BA, or to the Suffolk Biological Records Centre, c/o The Museum, High Street, Ipswich, IP1 3QH. Acknowledgements I would like to thank those recorders whose records have helped to compile this report: John Cross (JC); Russell Edwards (REd); Rafe Eley (RE); Gerry Haggett (GH); Robert St. Leger (RSL); Howard Mendel (HM); Norman Muddeman (NM); Nigel Odin (NO); Mike Parker (MP); Adrian Parr (AP); Frank Smith (FS); Steve Ward (SW); Geoff Welch (GW); Joy West (JW); and in particular Arthur Watchman (AW) whose detailed comment on species and general numbers is so valuable.
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References Morley, C. (1937). Final Catalogue of the Lepidoptera of Suffolk. Suffolk Naturalists' Society. M. R. Hall (MH) Hopefield, Norwich Road, Scole, Diss, IP21 4DY.
Trans. Suffolk Nat. Soc. 28 (1992)
Ipswich:
Plate 2: The Hรถrnet Moth (Sesia apiformis), wellknown from south-east Suffolk was recorded in the King's Forest, (p. 14).
Plate 3: This larva of the Convolvulus Hawk-moth (Agnus convolvuli) was found on the promenade at Southwold ÂŤn August, 1991. (p. 13).