Nottinghamshire Glow Worms 2018
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Nottinghamshire is fortunate in having one of the largest and most well known Glow Worm colonies in the UK. Found in the heart of Sherwood Forest, the former Pine plantation at Clipstone Old Quarter has almost become synonymous for producing the UK's earliest females during the Spring and Summer months.

We have studied Clipstone Old Quarter's Glow Worms since 2008 and spent hundreds of hours in the field and learned a great deal about them. But there is still much more to learn from a beetle which we originally thought had already offered its secrets to the world of science.

 
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2018 Glow Worm sightings (Clipstone Old Quarter unless otherwise stated)
Continuous coverage of our traditional Clipstone Old Quarter site is unlikely this year, but we aim to survey for larvae and adults as often as it is practically possible to do so. Larval surveys are conducted in Sections A, B, C and D.
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Glow Worms (both adults and larvae) are recorded as follows.....L = larva ..... M = male .....F = female
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Date   Stage   Additional notes
................   .L. .M .F.   ll
March 14th   0 0 0   No larvae found this evening. A relatively cool temperature of 7C was recorded from T2. Site visited from 18:00h-18:55h.
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March 26th   1 0 0   A single larva recorded early evening, measuring just 12mm and appearing to be very thin. A temperature of 9C was recorded at T2 and the site visited from 17:05h-18:15h.
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March 27th   0 0 0   No larvae found this evening. A temperature of 9C was recorded from T2, but it felt cooler after rain earlier in the day. Site visited from 17:00h-18:00h.
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April 3rd   0 0 0   No larvae found this evening. A temperature of 11C at T2, but it again felt much cooler after heavy showers priory to the survey. Site visited from 18:20h-19:20h.
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April 5th   0 0 0   No larvae recorded. The temperature at T2 was 10C, but it again felt slightly cool, despite a fine sunny day. Site visited from 18:00h-19:00h.
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April 6th   3 0 0   Three larvae found in section D of the survey route this evening, measuring 20mm (x2) and 17mm. A temperature of 10C was noted at T2 and site visited from 18:40h-19:40h.
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April 7th   5 0 0   A total of five larvae found, including one larva hunting and attacking a Slug. The relatively small sizes indicate that most were likely to be male, measuring 15mm (x2) 17mm (x2) and one at 21mm. Site visited from 18:15h-19:25h, with a much milder temperature of 13C recorded at T2.
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April 8th   3 0 0   Another three larvae found in section D this evening, although one was the first dead larva to be found this year. Larval sizes were 17mm, 18mm and 20mm, a lower temperature of 9C recorded at T2 and the site was visited from 18:30h-19:35h.
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April 11th   0 0 0   No larvae recorded this evening. The temperature at T2 was down to 6C, feeling very cool after being dull and often wet over the past few days. Site visited from 18:55h-19:50h.
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April 17th   6 0 0   A total of six larvae found, including single 15mm, 16mm, 19mm and 20mm larvae, and two at 17mm. Site visited from 18:45h-20:00h and for the first time in several days after finally turning warmer. The temperature at T2 was measured at 13C.
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April 18th   5 0 0   Five larvae found during this evening's survey, including the first larva recorded along Section A since 19/03/17. Larval sizes included lengths of 16mm, 17mm and 18mm, 20mm and 24mm. A very warm temperature of 19C recorded at T2 and site visited from 19:35h-20:50h.
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April 20th   1 0 0   Just a single 14mm larva found in Section B this evening, after what was another very warm, dry day. Site visited from 19:25h-20:25h, with a temperature of 17C at T2.
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April 21st   2 0 0   An early morning visit resulted in two female larvae being found, measuring 22mm and 24 mm. Of special note however, was a single 28mm larva, found at a new location on the edge of the forest at approximately SK6131367380. This is situated along the southern edge of the forest, where it borders arable land to the west of Edwinstowe. This area has been surveyed for Glow Worms several times previously (both day and night) over a number of years.
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April 22nd   2 0 0   Two larvae found this evening measuring 18mm and 22mm. Site visited from 18:55h-19:55h, with a temperature of 15C at T2.
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April 26th   3 0 0   Three larvae found along Section D of the survey area this evening measuring 13mm, 20mm and 22mm. Site visited from 18:55h-20:00h, with a temperature of 11C at T2.
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April 28th   1 0 0   A cool evening with only s single 20mm larva found in Section D. Site visited from 18:45h-19:40h, with a recorded temperature of 8C at T2.
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April 29th   2 0 0   Two larvae found this evening, with a dead 17mm larva in Section D and a 15mm larva in Section C. Site visited from 19:10h-20:10h, with a cool temperature of just 7C at T2.
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May 10th   1 0 0   Just a single 22mm larva found in Section B of the survey area this evening. Site visited from 19:00h-19:55h, with a temperature of 12C at T2.
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2018 larval size data

Following what has been the coldest Winter for a number of years, with some snow and frequent frosts, 2018 is already showing the signs of being a late season. Low daytime temperatures and often wet conditions, made it pointless beginning larval surveys any earlier than mid-March.

The first larva was recorded on March 26th, appearing rather thin after over-wintering. Early April has seen conditions become more mild and larvae have been found regularly since April 6th. This has allowed us to begin looking at the available larval size data, finding that Glow Worm larvae at Clipstone Old Quarter are continuing to become smaller. The average larval length for the same period in previous years is 19.14mm.

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Fig 01. ... Recorded larval size ranges during April 2018... Correct to April 22nd (pm)
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    9mm-15mm larval size range   Intermediate   19mm-28mm larval size range
.. .. 9mm 10mm 11mm 12mm 13mm 14mm 15mm .. 16mm 17mm 18mm .. 19mm 20mm 21mm 22mm 23mm 24mm 25mm 26mm 27mm 28mm
Section A .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 1 .. .. .. ..
Section B .. .. .. .. .. .. 1 .. .. .. 2 .. .. .. .. .. .. .. .. .. .. .. ..
Section C .. .. .. .. .. .. .. 1 .. 1 2 .. .. .. 1 .. .. .. .. .. .. .. ..
Section D .. .. .. .. .. 1 .. 2 .. 1 4 3 .. 1 6 1 2 .. 1 .. .. .. ..
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    9mm-15mm larval size range 16.00%   Intermediate 42.00%   19mm-28mm larval size range 42.00%
Total % .. 0.00 0.00 0.00 0.00 3.25 3.25 10.00 .. 6.50 23.00 10.00 .. 3.25 23.00 3.25 7.00 0.00 7.00 0.00 0.00 0.00 0.00
 
 
Latest temperature data and possible date of the first female Glow Worm

The listed 2018 average minimum and maximum temperatures, includes the data from November 2017 to April 2018 (www.metoffice.gov.uk). Based on the current temperature values and any similarity to previous years, we are predicting that the first female Glow Worm will appear at Clipstone Old Quarter around May 29-31st 2018.

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Fig 02. ... Average monthly minimum Winter temperatures 2008-2018
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    2008/09 2009/10 2010/11 2011/12 2012/13 2013/14 2014/15 2015/16 2016/17 2017/18
November - April   2.80C 2.08C 2.35C 3.28C 1.55C 3.33C 2.93C 3.59C 3.46C 2.47C
January - April   2.80C 1.62C 3.67C 2.75C 1.05C 3.62C 2.45C 2.35C 3.50C 2.68C
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Date of first female   27/05/09 24/05/10 13/05/11 30/05/12 08/06/13 18/05/14 23/05/15 03/06/16 20/05/17 29/05/18?
 
Fig 03. ... Average monthly maximum Winter temperatures 2008-2018
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    2008/09 2009/10 2010/11 2011/12 2012/13 2013/14 2014/15 2015/16 2016/17 2017/18
November - April   8.68C 8.04C 8.71C 9.79C 7.33C 10.29C 9.50C 10.26C 9.60C 8.46C
January - April   9.27C 7.67C 10.70C 9.75C 6.95C 10.89C 9.60C 9.30C 10.12C 8.50C
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Date of first female   27/05/09 24/05/10 13/05/11 30/05/12 08/06/13 18/05/14 23/05/15 03/06/16 20/05/17 29/05/18?
 
 
The Nottinghamshire Glow Worm Survey

The Nottinghamshire Glow Worm Survey (NGWS) is an ongoing project aimed at contributing useful distribution data on this decling species. For more information and to see the latest survey results contributed to the scheme, click the banner below. Please join in and if you do, contribute to the survey using the online form to send us your sightings.

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Clipstone Old Quarter survey route

Below is an arial map showing both former and current survey area and routes taken each evening. For female Glow Worms, sections O, K, J and D may again form our survey route this year. Larval surveys are made in sections A, B, C and D. The two yellow dots show the two locations (highest and lowest points on site) where the temperature is taken during the season.

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