Official name
Synonyms
Gelis spurius [Soortenregister]
Pezomachus spurius [Schwarz 1995]
see more on: www.gbif.org

CONTENTS
1. Distribution
2. Behaviour
3. Plant relations
4. Parasitic relations
5. Identification
1. DISTRIBUTION
The ichneumon wasp Gelis spurius is a common wasp in the Netherlands [Waarneming.nl].
2. BEHAVIOUR
2.1. ACTIVITY
The female can be found the whole year through and overwinter as adults [Schwarz 1998].
The specimen used in this post was caught in februari, see here.
It is suspected the species is multivoltine [Schwarz 1998].
2.2. DEVELOPMENT
The species is an idiobiont ectoparasitoid that can occur as primary and as well as secundary pseudohyperparasitoid on ichneumonid and braconid wasps [Schwarz 1998],[Schwarz 2002].
3. FOOD PLANTS
The adults wasps feed on nectar and honeydew [Schwarz 1998]. Flower visits are limited to specific weather conditions, like during drizzle or muggy weather and is probably secondary to licking up honeydew and moist from leaves [Schwarz 1998]. Possibly pollen grains stuck on the sticky surfaces of hairy leaves are eaten as well [Schwarz 1998].
In literature the following plants and groups are cited in the context of licking up food and moisture:
Birch family (Betulaceae) | – Corylus avellana (Common hazel) [Schwarz 1998] – Alnus alnobetula (Green alder) [Schwarz 1998] |
Netle family (Urticaceae) | – Urtica dioica (Stinging nettle) [Schwarz 1998] |
Feeding in captivity
In order to be able to photograph the wasp properly I had kept her for a longer duration (few weeks) and fed her twice per day a cotton soaked in water and a cotton soaked in sugar water.
After two weeks (March 9) the wasp escaped during a photoshoot and I could not find her anymore. But after some time I noticed her on a dry cotton lying somewhere on the desk and she was clearly trying to drink from it. Apparently she was conditioned on the cottons during her captivity.
4. PARASITIC RELATIONS
Gelis spurius is connected as pseudohyperparasitoid on Ichneumonidae and Braconidae, and can be found / is reared from a wide range of hosts.
The following prey groups and species occurring in the Netherlands [Soortenregister] are cited in literature, including the primary host (hyperparasitism):
Flies (Diptera) | Lauxaniidae Sapromyza [Schwarz 2002] Tephritidae Rhagoletis – Rhagoletis alternata [Schwarz 2002] |
Moths (Lepidoptera) | Adelidae Adela – Adela reaumurella [Schwarz 2002] of Incurvariidae Incurvaria – Incurvaria pectinea [Schwarz 2002] Psychidae Dahlica [Schwarz 2002] Psyche – Psyche casta [Schwarz 2002] |
Wasps (Parasitica) | Braconidae Apanteles [Schwarz 2002] Coeloides – Coeloides scolyticida [Schwarz 2002],[Schwarz & Shaw 1999] parasite on: Scolytus scolytus or Scolytus multistriatus Microplitis – Microplitis mandibularis [Schwarz 2002],[Schwarz & Shaw 1999] parasite on Noctuidae Ichneumonidae Hyposoter [Schwarz 2002] parasite on: – Melitaea cinxia |
Parasitic species outside the Netherlands:
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5. IDENTIFICATION
Length: 1,8 – 4,4 mm
Female are apterous [Schwarz 2002].
Males are brachypterous or macropterous [Schwarz 2002].
Genus
The genus Gelis can be recognized by the following characters:
1. Achterlijf: terga 2 and 3 fully separated, or only partially or unclearly merged [Schwarz 1995] (here clearly separated)
2. Achterlijf: tergum 1 with or without dorsal lateral carina [Schwarz 1995] (here with carina)
3. Achterlijf: tergum 1 not or rarely apically striped [Schwarz 1995] (here not striped)
4. Achterlijf: if tergum 1 apically striped than laterotergite of the 2nd abdominal segment separated and wide [Schwarz 1995] (Here not the case)


HEAD
1. Head black [Schwarz 2002]
2. Antenne: flagellum segments basally or entirely orange- to yellowbrown [Schwarz 2002]
3. Scapus (antennal segment 1): seldom partly dark [Schwarz 2002]
3. Antenna: with 16-19 segments [Schwarz 2002]
4. Antenna: antennal segment 3 is 2,2-2,5x longer than wide (here 2,4x) (lateral view) [Schwarz 2002]
5. Antenna: antennal segment 7 is 1,1-1,6x longer than wide (here 1,6x) (lateral view) [Schwarz 2002]
6. Head structure granulated [Schwarz 2002]

7. Ocelli: distance between rear ocelli ( OOL ) is about 0,7-1,2x the distance between the rear ocellus and the inner eye edge ( POL ) [Schwarz 2002] (here ±1,2x)

8. Head: behind eyes somewhat strongly to weakly narrowed [Schwarz 2002]
9. Frons: densely haired, finely to very finely puntured [Schwarz 2002]
10. Cheek: is 1,0-1,2x longer than mandible base width, 1,5x in small specimen (here ±1,0x) [Schwarz 2002]
11. Malar space without a furrow or weakly developed [Schwarz 2002] (here weakly developed)
12. Clypeus: black, seldom brown (here black) [Schwarz 2002]
13. Clypeus: convex [Schwarz 2002]
14. Clypeus: with clear punctation [Schwarz 2002]
15. Clypeus: lower edge weakly convex or sometimes straight, without tooth [Schwarz 2002]
16. Mandible: upper tooth somewhat longer than lower tooth [Schwarz 2002]
17. Mandible: except for teeth, yellow-brown to reddish (here reddish) [Schwarz 2002]
18. Palps: brown to orange-brown [Schwarz 2002]
19. Eye: width is 1,8-2,1x length temple [Schwarz 1995]
BORSTSTUK
1. Thorax black [Schwarz 2002]
2. Mesonotum and pronotum not separated [Schwarz 2002]
3. Mesonotum: length = 0,5-0,7x width (here ±0,7x) [Schwarz 2002]
4. Mesonotum: almost flat or moderately convex [Schwarz 2002]
5. Mesonotum: front with weak indentation in middle [Schwarz 2002]
6. Scutellum: not, or weakly limited, very short (here weakly limited) [Schwarz 2002]
7. Furrow between mesonotum and propodeum level and narrow [Schwarz 2002]
8. Mesonotum: length = 0,5-0,7x length area anterior [Schwarz & Shaw 1999]
9. Mesosternum: clearly shorter than width basal flagellum segment (segment 3) [Schwarz 2002]
10. Propodeum: dorsally densely haired, not clearly less than mesonotum [Schwarz 2002]
11. Propodeum: dorsally convex, as a rule not higher than mesonotum [Schwarz 2002]
12. Propodeum: with transverse carina, in middle widely interrupted or only indicated [Schwarz 2002]
13. Legs: orange to orangebrown [Schwarz 2002]
14. Hindleg: femora 3,2-3,6x longer than high (here ±3,3x) [Schwarz 2002]
15. Hindleg: tibia thickend, 5,3-6,0x longer than high (here ±5,3x) [Schwarz 2002]
16. Hindleg: shin dorsally densely haired [Schwarz 2002]
ABDOMEN
1. Abdomen black [Schwarz 2002]
2. Terga: from tergum 2 laterally orange- to yellowbrown [Schwarz 2002]
3. Terga: from tergum 6 or 7 entirely orange- to yellowbrown [Schwarz 2002]

4. Terga: narrow apical edges orange- to yellow-brown [Schwarz 2002]
5. Tergum 2: edges orange- to yellow-brown [Schwarz 2002]
6. Abdomen: densely haired [Schwarz 2002]
7. Tergum 1: length is 1,3-1,6x width [Schwarz 2002]
8. Tergum 2: length laterotergite is 3,1-4,8x width (here ±3,1x) [Schwarz 2002]
9. Ovipositor: shafts are 0,6-0,7x longer than shin III (hindleg) (here ±0,7x) [Schwarz 2002]
10. Ovipositor: with clear teeth ventrally [Schwarz 2002]

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Literature
Schwarz 1995 Schwarz M., 1995. Revision der westpaläarktischen Arten der Gattung Gelis THUNBERG mit apteren Weibchen und Thaumatogelis SCHIEDEKNECHT (Hymenoptera, Ichneumonidae). Teil 1. – Linzer biologische Beiträge – 0027_1: 5 - 105.Schwarz 1998 Schwarz M., 1998. Revision der westpaläarktischen Arten der Gattungen Gelis THUNBERG mit apteren Weibchen und Thaumatogelis SCHMIEDEKNECHT (Hymenoptera, Ichneumonidae). Teil 2. – Linzer biologische Beiträge – 0030_2: 629 - 704.
Schwarz 2002 Schwarz M., 2002. Revision der westpaläarktischen Arten der Gattungen Gelis THUNBERG mit apteren Weibchen und Thaumatogelis SCHWARZ (Hymenoptera, Ichneumonidae). Teil 3 – Linzer biologische Beiträge – 0034_2: 1293 - 1392.
Schwarz & Shaw 1999 Schwarz M. & Shaw M., 1999. Western Palaearctic Cryptinae (Hymenoptera: Ichneumonidae) in the National Museums of Scotland, with nomenclatural changes, taxonomic notes, rearing records and special reference to the British check list. Part 2. Genus Gelis THUNBERG (Phygadeuontini: Gelina). – Entomologist's Gazette – 50(2): 117 - 142.
Soortenregister Nederlands Soortenregister
Waarneming.nl Waarneming.nl
Citation
Krischan, O.R., 2025. Gelis spurius. Kerfdier, www.kerfdier.nl. Accessed on [date month year].