Nottinghamshire Glow Worms 2022

Fig 01. ... Glow Worm larval size ranges found at Clipstone Old Quarter during March 2022 Data correct as of 01/03/22
..
		9mm-15mm larval size range								Intermediate				19mm-28mm larval size range
Section		9mm	10mm	11mm	12mm	13mm	14mm	15mm		16mm	17mm	18mm		19mm	20mm	21mm	22mm	23mm	24mm	25mm	26mm	27mm	28mm
A	..	1	0	0	1	0	0	1	..	0	0	0	..	0	0	0	0	0	0	0	0	0	0
B	..	0	0	0	0	0	1	1	..	1	0	2	..	2	0	0	1	0	1	0	0	0	0
C	..	0	0	0	0	0	1	0	..	0	0	0	..	0	0	0	1	0	0	0	0	0	0
D	..	0	0	0	0	1	3	2	..	0	1	3	..	2	1	2	1	0	0	1	0	0	0
..
		9mm-15mm larval size range 00.00%								Intermediate 00.00%				19mm-28mm larval size range 00.00%
Total %	..	0.00	0.00	0.00	0.00	0.00	0.00	0.00	...	0.00	0.00	0.00	...	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00

Larval survey data 2009-2022

Data gained from larval surveys during March, April and May in most years, showed a decrease in the average length of Glow Worm larva at Clipstone Old Quarter over that time. We found that the average larval size from Spring 2009 to 2014 was 20.32mm, based on the data gathered from a total of 771 larvae.

It also showed that larvae were considerably larger on average in 2009 (22.21mm) than in any of the following years, equating to 1.89mm larger than the average produced between 2010 and 2015. This has continued to be the case and the average length of larvae in 2016 was found to be just 17.99mm, showing a decrease of 4.22mm.

The data in the table provided in Fig 02 below, is presented as (for example) 17.00mm/tL6. An explanation of this would be 17.00mm (the average larval length) / tL6 (taken from a total of six larvae) but this obviously changes daily after each survey. The Spring average follows the same principle, but the average is obviously taken from the total larvae found that particular Spring.

Fig 03. ... Glow Worm larval averages during Spring 2009-2022 Data correct as of 01/01/22

....

Week/period

2009

2010

2011

2012

2013

2014

2015

2016

2020

2021

March 22-31

.....

18.03mm/tL27

21.16mm/tL6.

.....

17.90mm/tL13

18.44mm/tL90

17.63mm/tL28

00.00mm/tL00

April 1-7

23.33mm/tL3.

21.27mm/tL13

18.64mm/tL70

19.00mm/tL5.

....

18.65mm/tL24

18.16mm/tL6.

16.46mm/tL13

19.75mm/tL4

April 8-14

21.14mm/tL14

19.58mm/tL17

19.19mm/tL31

19.66mm/tL9.

17.11mm/tL9.

18.27mm/tL59

19.11mm/tL16

15.00mm/tL3

April 15-21

20.45mm/tL10

20.78mm/tL18

19.78mm/tL53

23.20mm/tL5.

18.34mm/tL34

18.62mm/tL22

20.66mm/tL8.

18.26mm/tL20

18.00mm/tL1

April 22-29

23.32mm/tL25

18.74mm/tL53

19.97mm/tL39

18.77mm/tL9.

18.61mm/tL25

20.20mm/tL36

18.83mm/tL6*

21.66mm/tL3

April 30-May 6

22.95mm/tL20

23.20mm/tL5.

21.87mm/tL8.

20.95mm/tL22

19.85mm/tL16

21.87mm/tL21

17.66mm/tL15

19.75mm/tL4

May 7-14

22.08mm/tL17

23.25mm/tL4.

.....

22.30mm/tL10

21.62mm/tL21

21.25mm/tL4.

18.22mm/tL22

19.75mm/tL4

May 15-22

19.66mm/tL60

21.71mmtL/8

19.97mm/tL34

May 23-30

19.11mm/tL90

Spring avg

22.21mm/tL89

20.92mm/tL116

19.58mm/tL228

20.45mm/tL66

19.52mm/tL103

19.53mm/tL169

N/A

17.99mm/tL83

N/A

The size data produced since 2010 has been remarkably consistant where sufficient data was collected, showing a variation of just 1.40mm. 2021 data is not included in this. Breaking the data down further, the average size variation in three of the years since (2011, 2013 and 2014) showed variation as little as 0.06mm. If we exclude the 2009 size data on the basis of being unusually large, then an average larval size at this site would be approximately 20.00mm. The relative consistant larval sizes suggests that variations in rainfall and temperature between November and March in any year, actually had no influence on larval size.

The Glow Worm is without doubt, one of our most fascinating insects. Famous for the ability to produce its own light, the green bioluminescence emitted by the female Glow Worm has formed the basis of countless fairy tales and folklore over centuries. Despite still regarded by some authorities as being both nationally and locally common, this delightful beetle has been proved to be in serious decline. The data collected by a number of local recorders over the past ten years, has helped confirm both decline and demise in Nottinghamshire's Glow Worm populations. However, getting people to sit up and take notice has proved to be rather difficult and it doesn't help when those very same authorities continue to denounce any existance of decline. Habitat loss through urbanisation and industrial development, the use of pesticides and herbicides in modern farming practices and the increase in light pollution, are all thought to have contributed to the Glow Worm's decline.
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But Nottinghamshire is fortunate in having one of the UK's largest and most famous Glow Worm colonies in the shape of Clipstone Old Quarter. For many years, Clipstone Old Quarter (located deep within the heart of Sherwood Forest) was synonymous for producing the UK's earliest larvae and females and with the 2022 glowing season only a few months away, there is much to look forward to.

Help monitor Glow Worm distribution - contribute your records Members of the public can contribute to the Nottinghamshire Glow Worm Survey and we welcome any Glow Worm records from within VC56 Nottinghamshire. The easiest way to contribute your records, is by completing the simple online survey form on the right. The form can also be used to send in any old Glow Worm records you may have, as old records are important in helping to determine a more accurate picture of Glow Worm distribution and how it has changed over time. And it is just as useful if we know where Glow Worms are not found, so please remember that negative results from a site are equally as important as positive results and will help our mapping of the Glow Worm's distribution. Useful Glow Worm links on www.eakringbirds.com The Nottinghamshire Glow Worm Survey - About the NGWS and archive of reports and records The Glow Worm in Nottinghamshire - A general introduction to Glow Worms in VC56 Nottinghamshire Historical records of the Glow Worm in Nottinghamshire - Nottinghamshire's known Glow Worms sites
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Nottinghamshire Glow Worm records 2022 Contributors to the Nottinghamshire Glow Worm Survey 2022: Thanks to the following people who have sent in their survey results: