Official name
Synonyms
Spilomena troglodytes [Soortenregister]
Spilomena vagans
see more on: www.gbif.org
Etymology
troglodytes
Greek: cave-dweller
Contents
1. Distribution
2. Behaviour
3. Plant relations
4. Prey relations
5. Parasitic relations
6. Identification
1. DISTRIBUTION
Spilomena troglodytes is a rare wasp [Waarneming.nl] occurring throughout the Netherlands [Peeters et al. 2004],[Klein 1999] with an exception of the coastal provinces and the wadden islands [Peeters et al. 2004]. It is the most common representative of the genus in the Netherlands [Klein 1999].
2. BEHAVIOUR
2.1. ACTIVITY
The species is active from beginning of June to half September [Peeters et al. 2004].
Males frequently can be found swarming around bushes and trees [Peeters et al. 2004],[Lomholdt 1984].
2.2. DEVELOPMENT
Nest
Females nest in existing cavities [Peeters et al. 2004],[Bohart & Menke 1976],[Blösch 2000],[Klein 1999],[Lomholdt 1984] in old wood [Bohart & Menke 1976],[Blösch 2000],[Klein 1999],[Lomholdt 1984], twigs [Bohart & Menke 1976] and abandoned beetle boreholes [Klein 1999],[Lomholdt 1984], with a preference [Lomholdt 1984] of those made by Anobium sp. (Anobiidae) [Peeters et al. 2004],[Lomholdt 1984] (Anobium rufipes [6], Microbregma emarginatum [Vikberg 2000]). She will gnaw her own nest as well in the marrow of plant stems [Peeters et al. 2004].
Existing boreholes are cleaned before use [Peeters et al. 2004],[Lomholdt 1984]. Gnawed corridors are about 4-12cm in length [Blösch 2000]. The corridors have a diameter of 1,0-2mm [Blösch 2000],[Danks 1971],[Schneider 1991] and a length of 3,5-6 mm [Danks 1971].
The brood cells are placed sequentially in a row within the nest cavity [Peeters et al. 2004],[Blösch 2000],[Lomholdt 1984]. The brood cells are separated by a 1-2mm thick bulkhead made of wood dust [Blösch 2000] or a 0,2-7mm wedge-shaped pith plug [Danks 1971]. Every cell contains 50-60 thrips [Peeters et al. 2004],[Lomholdt 1984]. Cells for females and males are equal in size [Danks 1971].
The filled nest is closed with a wood pulp plug that is tamped using the abdomen [Peeters et al. 2004]. The outermost layer is fortified by mixing the wood pulp with saliva that hardens as it dries [Peeters et al. 2004] into a somewhat shiny disc [Lomholdt 1984].
Females find their nest using smell and as a result normally take a lot of time to find it after returning from the hunt, which is typical in the genus Spilomena [Blösch 2000],[Lomholdt 1984]. They will scout around a large surface around the assumed nest position until they smelled it out using the antennae [Blösch 2000].
Development time
The development time of the relatively large (1,25 mm), weakly saussage-like bent [Lomholdt 1984] egg is unknown. The matt white cocoons are attached to the cell wall and occupy almost the entire cell length [Danks 1971].
Gender development
The male and female brood cells are randomly placed in the nest cavity [Blösch 2000]. There are more female than male cells which results in a surplus of female over males in a ratio of 2:1 [Blösch 2000].
2.3. BEE HOTEL
The males as well as the females can be found on bee hotels. Females use them to nest.
From my own observation of a male arriving early in the evening I suspect the males to use empty boreholes as resting place, see here.
2.4. MATING
The species is bivoltine [Schneider 1991].
2.5. HUNTING
The prey is transported using the mandibles [Bohart & Menke 1976],[Lomholdt 1984].
3. PLANT RELATIONS
3.1. WOOD
The following wood types are mentioned in literature as medium for the wasp to built her nests in:
Adoxaceae (Muskuskruidfamilie) | Sambucus (Elder) [Danks 1971] |
Betulaceae (berkenfamilie) | Alnus (Elm) [Peeters et al. 2004] Betula (Birch) [Peeters et al. 2004] Carpinus (Hornbeam) [Peeters et al. 2004] |
Pinaceae (Dennenfamilie) | Picea Picea abies (Norway spruce) [Vikberg 2000] |
Rosaceae (Rozenfamilie) | Crataegus (Hawthorn) [Peeters et al. 2004] Rubus (Bramble) [Van Lith 1955],[Danks 1971] |
Salicaceae (Wilgenfamilie) | Salix (Willow) [Peeters et al. 2004] |
Sapindaceae (Zeepboomfamilie) | Aesculus (Horse chestnut) – Horse chestnut (Aesculus hippocastanum) [Vikberg 2000] |
Fence poles [Peeters et al. 2004] or thatched roofs [Lomholdt 1984] may be used as well.
3.2. FOODPLANTS
Males feed with honeydew that is licked from leafs.
The following wood types are mentioned in literature as foodsources:
Apicaceae (Umbellifers) | Peucedanum [Blösch 2000] Foeniculum [Blösch 2000] Angelica [Blösch 2000] – Angelica archangelica [Blösch 2000] |
4. PREY RELATIONS
The species uses mainly nymphs of thrips (Thysanoptera) for her brood [Peeters et al. 2004],[Bohart & Menke 1976],[Blösch 2000],[Klein 1999],[Lomholdt 1984]. Observations have been reported on the use of Psyllids (Psyllidae) nymphs [Bohart & Menke 1976] and the nymphs of Scale insects (Coccidae) and Aphids (Aphidoidea) [Bohart & Menke 1976].
The following species and group occurring in the Netherlands [Soortenregister] are mentioned in literature:
Aphidoidea (Aphids) [Bohart & Menke 1976],[Blösch 2000] |
Coccidae (Scale insects) [Bohart & Menke 1976],[Blösch 2000] |
Psyllidae (Psyllids) [Bohart & Menke 1976] |
Thysanoptera (Thrips) [Bohart & Menke 1976] |
Preyspecies outside the Netherlands:
– | – |
5. PARASITIC RELATIONS
The following species and group occurring in the Netherlands [Soortenregister] are mentioned in literature:
Hymenoptera (Wasps) | Ichneumonidae (Ichneumon wasps) Neorhacodes – Neorhacodes enslini [Peeters et al. 2004],[Danks 1971],[Jacobs 2007],[Lomholdt 1984] Chalcidoidea (Chalcid wasps) Torymidae Torumus – Torymus armatus [Peeters et al. 2004],[Danks 1971 (als Diomorus armatus)] |
Diptera (Flies) | Chloropidae (Frit flies) Oscinella – Oscinella nigerrima [Bohart & Menke 1976] |
Parasitic species outside the Netherlands:
– | – |
6. IDENTIFICATION
Length males: 2 – 3 mm
Length females: 2,5 – 3 mm
Genus
The genus Spilomena can be identified using the following characters:
1. Forewing: with two submarginal cells [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
2. Forewing: submarginal cell 2 not petiolate [Jacobs 2007],[Klein 1999],[Dollfuss 1991]
3. Forewing: pterostigma large and almost semicircular [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
4. Forewing: radial cell longer than pterostigma [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
5. Forewing: radial cell tip sharp [Jacobs 2007],[Klein 1999],[Dollfuss 1991]
6. Forewing: with one discoidal cell [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
7. Thorax: notauli do not reach apical edge mesonotum [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
8. Abdomen: first abdominal segment not petiolate [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
9. Abdomen: entirely black [Jacobs 2007],[Klein 1999],[Dollfuss 1991]

1. Antenna with 12 segments [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
2. Abdomen with 6 segments [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
HEAD
1. Clypeus: evenly rounded [Bitsch 2022],[Jacobs 2007]
2. Mandible: usually light brown, seldom dark brown [Bitsch 2022],[Jacobs 2007]
3. Vertex: ratio distance between hind ocelli (OOL) : distance hind ocellus to eye edge (POL) = 1,4 – 2,0 [Jacobs 2007],[Dollfuss 1991], POL:OOL = 0,48-0,77 [Bitsch 2022]
4. Back head: less strongly developed [Bitsch 2022],[Jacobs 2007]
THORAX
1. Scutellum: frontal furrow narrow and without transverse carinae [Bitsch 2022],[Jacobs 2007],[Dollfuss 1991]
2. Mesonotum: apical edge without longitudinal grooves [Bitsch 2022],[Jacobs 2007]
3. Wing veins: brown [Bitsch 2022],[Jacobs 2007]
4. Propodeum: dorsal field propodeum not limited by carina, at least at the base with net-like wrinkles between the main sculpture [Bitsch 2022],[Jacobs 2007]
ABDOMEN
1. Tergum 6: with double longitudinal carina [Bitsch 2022],[Jacobs 2007]

specimen caught for identification on 10-vi-2021, length ±3mm



1. Antenna with 13 segments [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
2. Abdomen with 7 segments [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
3. Face and clypeus yellow, at least the front edge yellow (here face and clypeus) [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
HEAD
1. Clypeus: apical edge not or lightly indented (here lightly indented) [Bitsch 2022],[Jacobs 2007],[Dollfuss 1991]
2. Mandible: distally with small red-brown spot [Bitsch 2022],[Jacobs 2007],[Dollfuss 1991]
3. Clypeus: entirely or almost entirely yellow [Bitsch 2022],[Jacobs 2007],[Klein 1999]
4. Vertex: ratio distance between hind ocelli (OOL) : distance hind ocellus to inner eye edge (POL) = 1,4 – 2,0 (here ±1,4) [Jacobs 2007],[Dollfuss 1991], POL:OOL = 0,48-0,77 [Bitsch 2022]
5. Antenna: antennal members clearly restricted, bead-like [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
6. Antenna: antennal flag dark, at most more or less red-brown on the inside [Klein 1999]
THORAX
1. Scutellum: frontal scutellum furrow narrow and without transverse carinae [Bitsch 2022],[Jacobs 2007],[Dollfuss 1991]
2. Propodeum: dorsal field not limited by carina [Bitsch 2022],[Jacobs 2007],[Klein 1999],[Dollfuss 1991], at least at base with fine net-like wrinkles between the main sculpture [Jacobs 2007]

3. Middle leg: thorn tibia 2 with normal length [Bitsch 2022]
ABDOMEN
no specific characters
Literature
Bitsch 2022 Bitsch, J., 2022. Hyménoptères sphéciformes d'Europe: Systématique (3e partie) : Pemphredoninae et Philanthinae. France: Fédération française des sociétés de sciences naturelles.Blösch 2000 Blösch, M. (2000). Die Grabwespen Deutschlands – Lebens‐weise, Verhalten, Verbreitung. 71. Teil. In Dahl, F.: Die Tierwelt Deutschlands. Begr.: 1925. – Keltern (Goecke & Evers). – 480 S. 341 Farbfotos. ISBN 3‐931374‐26‐2 (hardcover). DM 98,–. Zool. Reihe, 78: 353-353. https://doi.org/10.1002/mmnz.20020780208
Bohart & Menke 1976 Bohart, R.M. & Menke A.S., 1976. Sphecid wasps of the world: a generic revision. - University of California Press, 695 p.
Danks 1971 Danks, H.V., 1971. Biology of some stem‐nesting aculeate Hymenoptera. Transactions of the Royal Entomological Society of London, 122.11: 323-395.
Dollfuss 1991 Dollfuss, H., 1991. Bestimmungsschlüssel der Grabwespen Nord-und Zentraleuropas. Stapfia, 24, 1-247.
Jacobs 2007 Jacobs, H.J., 2007. Die Grabwespen Deutschlands Ampulicidae. Sphecidae, Crabronidae–Bestimmungsschlüssel in Blank, SM & Taeger, A (Hrsg): Die Tierwelt Deutschlands und der angrenzenden Meeresteile nach ihren Merkmalen und nach ihrer Lebensweise, Hymenoptera III–Keltern, Goecke & Evers, 79: 1-207.
Klein 1999 Klein, W., 1999 De graafwespen van de Benelux: supplement. Jeugdbondsuitgeverij, 1-37. + Klein, W., 1996. De graafwespen van de Benelux. Jeugdbondsuitgeverij, 1-130.
Lomholdt 1984 Lomholdt, O., 1984. The Sphecidae (Hymenoptera) of Fennoscandia and Denmark. Fauna Entomologica Scandinavica, 4.1: 2.
Peeters et al. 2004 Peeters, T.M.J., C. van Achterberg, W.R.B. Heitmans, W.F. Klein, V. Lefeber, A.J. van Loon, A.A. Mabelis, H. Nieuwen-huijsen, M. Reemer, J. de Rond, J. Smit, H.H.W. Velthuis, 2004. De wespen en mieren van Nederland (Hymenoptera: Aculeata). – Nederlandse Fauna 6. Nationaal Natuurhistorisch Museum Naturalis, Leiden, knnv Uitgeverij, Utrecht & European Invertebrate Survey – Nederland, Leiden.
Schneider 1991 Schneider, N., 1991. Contribution à la connaissance des Arthropodes rubicoles du Grand-Duché de Luxembourg. Bull. Soc. Natur. Luxembourg, 92, 85-119.
Soortenregister Nederlands Soortenregister
Van Lith 1955 Van Lith, J. P., 1955. De Nederlandse Spilomena-soorten (Hym. Sphecidae). Entomologische Berichten, 15(24), 525-527.
Vikberg 2000 Vikberg, Vi,. 2000. A re-evaluation of five European species of Spilomena with a key to European species and relevance to the fauna of North Europe, especially Finland (Hymenoptera : Pemphredonidae). Entomologica Fennica. 11. 35-55. 10.33338/ef.84044.
Waarneming.nl Waarneming.nl
Citation
Krischan, O.R., 2025. Spilomena troglodytes. Kerfdier, www.kerfdier.nl. Accessed on [date month year].