CITIZEN SCIENCE AND FIREFLIES IN FLANDERS, BELGIUM. RESULTS FROM WAARNEMINGEN.BE, AN ONLINE SURVEY OF THE NATURE ORGANISATION NATUURPUNT *,³ Glimwormenwerkgroep, Natuurpunt, 11, 2800 Mechelen, Belgium. E-mail:
[email protected] 1 Natuurpunt Studie, Coxiestraat 11, 2800 Mechelen, Belgium. E-mail:
[email protected] ² Evolutionary Ecology Research Group, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, Wilrijk, Belgium. E-mail:
[email protected]
Glimwormenwerkgroep* & Natuurpunt Studie1 & Raphaël De Cock2,3
INTRO
STUDY AREA
From 1997 on, attempts for a lampyrid survey for Belgium were started, at insistence of and support by Robin Scagell and John Tyler founders of the British UK glow-worm survey. Since then various random calls were posted by radio, newspapers and the internet, in order to ask the general public to send in sightings of lampyrids (1997-2016). Thanks to the efforts of local researchers, enthusiasts and citizen science survey projects, we are getting a quite good image now of the distribution of lampyrid species in Flanders, Belgium. Here we present results on the distribution of the three glow-worm firefly species present in our region between 1945-2016: Lampyris noctiluca (Linnaeus, 1767), Lamprohiza splendidula (Linnaeus, 1767) and Phosphaenus hemipterus (Goeze, 1777).
We store all observations - also from other regions or countries. All species distribution data are shown here, except those we did not get permission for by the observers/website users. Phenology data shown are based on observations from Flanders region only (= area where Natuurpunt is active). Flanders is the Dutchspeaking northern portion and one of the communities, regions and language areas of Belgium.
LAMPYRID SPECIES of BELGIUM Lampyris noctiluca L. (Eng.: Common European glow-worm; Dutch: Gewone glimworm; Grote glimworm) ♀
DISCUSSSION & CONCLUSIONS
METHODS Data come from the waarnemingen.be database from the earliest observations till 31.VIII.2016, except observations with number = 0 (absence or unsure) and filtered for observer permission level for use of their data.
RESULTS Database total: 3932 observations (obs); 15125 individuals (ind) ♂
larva
Best known, most common species. Diverse number of habitats, as long as it is humid: roadsides, gardens, parks, meadows, banks, forest edges ... • Male: 15-18mm, winged, dark brown, with two small light spots adjacent bottom penultimate segment and not luminous in flight • Female: 13-25mm, wingless, brown with pinkish tones on lateral sides and ventrally, light organs only in last three abdominal segments • Larva: black with yellow-orange dots on segment angles, glowing with slow light pulses or when disturbed.
Oldest observations: ♂: 10.VII.1976 - ♀: 5.VIII.1945 – larva: 7.VII.1984 First seasonal appearance: ♂: 22.V - ♀: 5.V* – larva: 12.I Last seasonal appearance: ♂: 12.IX - ♀: 1.X – larva: 21.XII *earlier seasonal sightings considered as possible confusion of larval glows for adult females
For Flanders : ♂ n°obs: 136, n°ind: 354 - ♀ n°obs: 884, n°ind: 3150 - larvae n°obs: 414, n°ind: 1241
Glow tracks of male Lamprohiza splendidula L. noctiluca. Phenology of adults
Distribution of L. noctiluca per 1km squares in red
Lamprohiza splendidula L. (Eng.: “Central European firefly”; Dutch: Kleine glimworm/Vuurvliegje)
♀
♂
♀
larva
L. noctiluca. Phenology of larvae
Database total: 436 observations; 15319 (!) individuals Oldest observations: ♂: 24.VI.1955 - ♀: 21.VI.2003 – larva: 25.VIII.1985 First seasonal appearance: ♂: 09.VI - ♀: 15.VI – larva: 15.IV Last seasonal appearance: ♂: 16.VII - ♀: 21.VII – larva: 10.XI For Flanders : ♂ n°obs: 106, n°ind: 3832 - ♀ n°obs: 25, n°ind: 143 - larvae: 2 records only: these larvae only glow when disturbed, no “spontaenous” glows, camouflage body colour thus less conspicuous than other species
Greater demands on habitat and environment. Prefers forest valleys, clearings in forests and grasslands in woodlands. Males commonly known as 'fireflies' because they are the only Central-European lampyrids that fly aglow with a bright lime green bioluminescence between ca. 22:30-23:15 (~45min) L. splendidula. Phenology of adults • Male: 10mm, overall body colour brown with two conspicuous white kidney shaped light organs in 2 penultimate ventrites, glows at flight. • Female: 10-15mm, elytral stubs, pale whitish body colour, more than 4 light organs spread throughout the abdomen • Larva: brown leaf-like camouflage colour, flattened and wide, multiple lateral glow spots spread over the abdomen: only glows when disturbed, never “spontaneous” glow pulses.
Phosphaenus hemipterus (Goeze, 1777) (Eng.:Lesser glowworm; Dutch: Kortschildglimworm)
L. splendidula. ♂ peak seasons (> 50 indiv/record)
Distribution of L. splendidula per 1km squares in red
Database total: 155 observations; 676 individuals Oldest observations: ♂: 24.VI.2001 - ♀: 10.VI.1998 – larva: 25.VIII.1985 First seasonal appearance: ♂: 14.V - ♀: 10.VI – larva: 18.III Last seasonal appearance: ♂: 15.VIII - ♀: 5.VII – larva: 10.XI For Flanders : ♂ n°obs: 71, n°ind: 492 - ♀ n°obs: 3, n°ind: 143 - larvae: n°obs: 15, n°ind: 27
♂
♀
larva
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NATUURPUNT
PHENOLOGY • First ♂ records at start of June (but fly dark = less detectable!) • ♂ peak at end of June, then drop quite steadily till the end of July, from Aug till Oct occasional records • ♀♀ appear earlier in season with even few records begin of May; seem much more abundant but easier detectable → only glowing adult stage: ♀ peak during first week of July and keep high throughout July. Absolute numbers ♀♀ highest end of July when few males seem present: may represent “wall flowers” i.e. appeared to late in the season and die unmated. • Larval records start from March (nocturnal T° > 10°C). In Spring also diurnal records. Numbers increase towards mid May, then decrease till mid Sept – probably due to cohort that turned into adults + shorter and less dark summer nights. Occasional summer peaks in local larval numbers probably due to favourable weather and light conditions (e.g. rain, high noct. T°, no moonlight). After mid Sept numbers increase again: more humid weather and new generation (+ earlier dark thus higher detection chances). In Nov till half Dec few larvae observed (freezing! Sometimes hibernating larvae are reported). No larvae observed in January, few in February (obs. of hibernating larvae). DISTRIBUTION • Records W and N of Brussels are older (historic) or more recent unverified obs. that stay unconfirmed: presence unsure here • Abundant and large (meta)population in forest and adjacent zones South-East and even into Brussels Region. • Recently (last 10 yrs) confirmed from small and isolated locations between Brussels and the lines towards Genk and Maastricht (NL) • Known to be more common on the other side of the river Meuse (E of Maastricht, S-E of Luik/Liège, Namen/Namur, Dinant) and further almost all over Germany. • In Flanders much rarer and more vulnerable than previously thought: might candidate as Red Data Book species. Typical of old and alluvial forest, but found in small, vulnerable landscape elements (old hedges, shrubs, woodlots). Seems dependent on thick humid leaf litter layer PHENOLOGY • ♂♂ appear first in 2nd week of June and peak in 3rd week of June, coinciding with appearance of first ♀♀. Short explosive season ends abruptly 3rd week July • ♂ peak usually around 21st June •♂ “fireflies” seem more abundant than ♀ “glow-worms”, as they steal the “glow show” DISTRIBUTION • Apart from occasional sightings, many records thanks to focused sampling with pheromone and pitfall traps (2002, 2003) • Usually found in Southern and Central part of Flanders (Brussels, Leuven, towards Ghent and Antwerp) where soils contain higher % loamy fractions. Also present in other (sandy) regions, usually on alluvial soils. Often overlooked ! • Frequently in gardens and parks: even Brussels Royal Park
♀ : only 3 records: 4.VII.2004 + 5.VII.2013 + 10.VI.1998
Least known species, probably because of small inconspicuous flightless males crawling on the surface during daytime; females do not glow at night. Favourite habitats: gardens, parks and forests. Especially on sultry days males have been observed crawling in large groups on paths, walls, between plants tracking pheromone plumes emitted by hidden females.... • male: 10 mm, black, short elytra and wings and long antennae, two glow organs on the penultimate segment. Diurnal ! • Female: 10mm, brown, pinkish sides, found mostly during twilight, but usually not glowing, two light spots in the penultimate segment. • larva: elongated, brown the top, pinkish on the under and lateral sides when fat, 2 glow spots in for the penultimate segment (glows “spontaneously” with long slow pulses or when disturbed)
DISTRIBUTION • Quite common in whole of Flanders, highest densities in broad river and stream valleys (Scheldt, Senne, Dyle, Demer, Nete, Rupel, Herk, Bosbeek (Limburg), …), possibly undersampled along Meuse • Lacking in coastal “polder” areas (historically mudflats & salt marshes) • Absent in highly urbanised and industrialised areas (Brussels, Antwerp, Ghent, Bruges)
Distribution of Ph. hemipterus per 1km squares in red
is a Flemish independent volunteer organization:
• protects and manages vulnerable and endangered nature in Flanders • with over 100,000 members • harbours over 180 local and regional study workgroups • Citizen science survey website and database www.waarnemingen.be (since 2005) • keeps an eye on the health of the Flemish countryside and provides the scientific basis for the government’s nature management. • The Glow-worm workgroup is one of such 10 region-wide workgroup represented by Natuurpunt.
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PHENOLOGY • Broad ♂ season starting 2nd week of May till 3rd week August • Clear spectacular ♂ season peak: last week of June & 1st week of July with a shoulder during 2nd-3rd week of July and few records afterwards • ♀: to few data • Larval season starts end of March: often diurnal larvae. Almost no records during adult season and sporadic records of nocturnal and glowing larvae in late Summer and Autumn
Ph. hemipterus. Phenology males & larvae
Partnership & foundation of the Glow-worm workgroup In 2014 I (last author) approached Natuurpunt with the request to found the “Glow-worm workgroup” (in Dutch: Glimwormenwerkgroep) Goals: • to obtain a much wider platform & professional back-up team in order to assist in spreading calls for firefly surveys, divulge lampyrid species information for a wide audience • To store, manage and analyse the gathered data by means of Natuurpunt’s specialised survey website: www.waarnemingen.be The glow-worm workgroup has now: • its own webpage: https://www.natuurpunt.be/afdelingen/glimwormenwerkgroep • FB-page: “Glimwormenwerkgroep natuurpunt” • Lampyrid specific forms and information on waarnemingen.be
Acknowledgments: all volunteers who provided observations; Annelies Jacobs of Natuurpunt Studie for support; Robin Scagell and John Tyler for insistance and support. Photo credits: All photos come from observers of waarnemingen.be. Lampyris noctiluca: ♂ – Damien Grégoire // ♀ : Jan Van Uytvanck - // larva - Robert Van Dingenen; Lamprohiza splendidula: ♂ - Philippe Vanmeerbeeck; ♂ glow tracks: Winnipeg Limburg // ♀ glowing - Jean Claude Claes // ♀ - Eric Wille // larva - Stephane Claerebout; Phosphaenus hemipterus: ♂ - Gert Van Heghe // ♀ : -R. De Cock // larva - Danny VG
