LCES News February 2003
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Lancashire and Cheshire Entomological Society Newsletter Incorporating The Cheshire Moth Group Newsletter February 2003 Number 1008 1 Welcome! Welcome to the latest LCES and CMG newsletter. Originally this issue was planned for Christmas but with pressures of work it had to be delayed – apologies! But there is good news. The 2001 lepidoptera report for VC58 is now complete. This is downloadable from the LCES, CMG and rECOrd web sites. Despite the wintry weather, there are signs of spring in the air. As I write this evening, the trap already contains 4 Pale Brindled Beauty and a Spring Usher and before too long the sallow blossom will be out together with the Quakers and Clouded Drabs. Hopefully this year will be better than the cold, wet, windy summers we seem to have had of late. Field Trips – 2003 Meetings Not much organised so far – if you fancy leading a field trip let me know and I’ll include details next issue. National Moth Night is the 12th April this year. The events we know about are: Events in Cheshire for the National Moth Night in 2003 are still to be arranged. Watch this space! Weather permitting we will try to trap at Pym Chair/Goyt Valley for Red Sword-grass. Please contact Adrian Wander BEFORE travelling. A National Moth Night moth trapping event at Weaver Valley Parkway. Meet at the car park off the A5018 opposite Morrison's Supermarket (SJ656669). Drop in at any time. For further details contact: Brian Jaques on: 01606 891242 Field Trip Reports 29th September: Crimes Lane, Beeston This was an excellent outing and a very informative field trip looking at leaf mines. The day was a great success and yielded 28 new 10km grid square records. Highlights included Stigmella paradoxa and incredible numbers of Coleophora peribenanderi. It seemed like every patch of thistle in the area contained cases of this moth. Coleophora peribenanderi Stigmella paradoxa 1 1 SD0 SE SD0 SE 9 9 8 8 7 7 6 6 5 5 4 4 3 3 SJ 1 2 3 4 5 6 7 8 9 SK0 1 2 SJ 1 2 3 4 5 6 7 8 9 SK0 1 2 The cluster of records in the South West of the county represent the fruits of the days work. 2 Cnephasia’s in VC58 – an update Many thanks to all who sent on either directly or through Steve Hind specimens of Cnephasia for identification. All where either C. asseclana, C. incertana or C. stephensiana. May I take this opportunity to ask again for any Cnephasia from this season be sent to me again to further the study and distribution of this difficult group within Cheshire. Remember, look out for any on the wing during the months of May, mid-July and into August, these are usually the interesting ones! Cnephasia incertana (Light Grey Tortrix) Light Grey Tortrix (Cnephasia incertana) 0SD SE 1 9 SD0 SE 8 9 8 7 7 6 6 5 5 4 4 3 3 SJ 2 3 4 5 6 7 8 9 0SK 1 SJ 1 2 3 4 5 6 7 8 9 SK0 1 2 On the left we show the records of Light Grey Tortrix when Jon first put his request out in issue 6. On the right is the current status following the hard work of last year. Please send to: Jon Clifton, Kestrel Cottage, Station Road, Hindolveston, Norfolk, NR20 5E The Status of Lempke’s Gold-spot Plusia putnami gracilis in VC58 (Cheshire) - including comparison with surrounding Vice-counties 1. Current Status In VC58, this species is currently considered a major rarity. The first ever confirmed record was in July 2001 at Arnfield Reservoir (Shane Farrell, Paul Greenall, Adrian Wander, Steve Hind, Paul Hill), close to the boundary with VC57 at SK0197. Whilst there have been previous references to this species being recorded in VC58, none have ever been substantiated by retaining a specimen (and after reference to the genitalia), which is normally required for a Vice-county first. Retention of a specimen and dissection is still required for the acceptance of records for this species in VC58. A second record of two separate individuals in Cheadle Hulme (Geoff Lightfoot) at SJ8786 in September 2002 prompted me to consider that this species may, in fact, be more common in VC58 than is generally believed. These latter individuals displayed characters of both species and it was only after dissection (see the scan of the dissected plate below) that their identity was confirmed. GL retained the specimens in light of the 2001 records and ‘as there was something about them’ which made him suspect Lempke’s Gold-spot; his experience and observation skills were clearly well-founded. Adrian Wander was also suspicious about two specimens retained from his garden last year and made the following comment, ‘I had two Gold Spots from August that I did over the weekend: one a good, dark, one with pointed ends to the gold spot, the other one smaller, paler with nice rounded ends to the gold spots. I didn't 3 have a Gold Spot plate for reference so I did the dark one first. No problem - classic Gold Spot gen. I then did the pale one - no problem Classic Gold Spot gen! If I had been in the fens I would not have bothered keeping the specimen and would have recorded the moth as Lempke's. It was only because it would have been a new garden record and a very good VC58 record that I kept the specimen - good job I did.’ If even experts like Adrian can be ‘fooled’ from external characters, then hopefully readers can understand our caution in accepting records for the rarer Lempke’s Gold-spot! 2. Confirmation of Records It is appreciated that many recorders will be hesitant to kill and retain specimens of any moth, let alone one which is as attractive as either Gold-spot or Lempke’s Gold-spot. Some recorders will refuse point blank to take such action simply to confirm a species for just, in most cases, their own ‘garden list’. In such circumstances it is recommended that the specimen is held in Genitalia plate of one of the Cheadle Hulme specimens in 2002. the refrigerator for a few days until it can be referred to someone for confirmation if Lempke’s Gold-spot is suspected. A member of the Cheshire Panel should be consulted in these circumstances and an assessment can then be made as to whether or not the specimen is worth dissecting and then a final decision can be taken. Details of the contacts can be found on the website at www.consult-eco.ndirect.co.uk/lrc/mothg.htm Alternatively, or if the recorder takes the decision not to dissect, they should be recorded as Gold-spot, this being the more likely species. If specimens are to be retained then they can be killed within a minute or two in the freezer and then retained for an almost indefinite period in the freezer or alternatively out of the freezer in a pot. If not stored frozen, do ensure that the pot is well sealed as insect pests (dust mites etc.) can often eat the body parts to the distress of the recorder! Specimens can be sent to me, Adrian Wander or Steve Hind for dissection if required. It should be noted that although the males can be readily split by assessing the genitalia, this is almost impossible in the females. That said, if we get together more samples then perhaps more reliable female genitalia features will become apparent that will allow future female specimens to be positively identified. I have listed the main general external features below and also include within this article a photograph of one of the specimens captured at Arnfield in 2001 along with a specimen of Gold-spot. 3. External separation features and flight period Whilst both species can only be definitely split by appraising the genitalia (and then only generally males), it is sometimes possible, with care, to make a ‘best guess’ identification. However, a ‘best guess’ identification is all this can be. The following external identification features are not totally reliable and tend to form a cline in features between one species and another. As mentioned above, in VC58 dissection will still always be required to allow records for Lempke’s Gold-spot to be accepted. Retention of occasional voucher specimens is extremely unlikely to have any negative impact whatsoever on the population of a species such 4 as this; also the features listed below will hopefully help to reduce the numbers requiring dissection to a minimum. Turning to the features that can be used to reduce dissections, in general, Lempke’s Gold-spot has a warmer golden brown ground colour and normally does not show the stronger contrast often seen in Comparison shot with Lempke’s Gold-spot on the left and Gold-spot. The wing-shape Gold-spot on the right. Both captured at Arnfield (forewing) is usually slightly Reservoir July 2002 different; Lempke’s Gold-spot often has a concave costa (compared with a straight or slightly bulging costa in Gold-spot); furthermore the forewing of Lempke’s Gold-spot often appears broader and more pointed as a result of the fact that the costa is generally shorter in relation to the termen than in Gold-spot. This makes the forewing appear shorter in length when compared with Gold-spot. The two golden panels on the forewing are usually much rounder in Lempke’s Gold-spot and the classic separation character is indicated by the shape of the silvery/golden panels near the apex; the largest one is usually blunt in Lempke’s Gold-spot at the proximal end, whereas in Gold-spot it forms a point.