Official name
Synonyms
Crossocerus annulipes [Soortenregister]
Blepharipus annulipes
Blepharipus ambiguus
Coelocrabro ambiguus
Crabro ambiguus
see more on: www.gbif.org
Etymology:
annulipes
Latin: having a ring-shaped foot
CONTENTS
1. Distribution
2. Behaviour
3. Plant relations
4. Prey relations
5. Parasitic relations
6. Identification
1. DISTRIBUTION
Crossocerus annulipes is an uncommon wasp [Waarneming.nl] that occurs spread throughout the Netherlands [Peeters et al. 2004],[Klein 1999], but is not present in meadows and polder areas, and on the wadde islands [Klein 1999].
2. BEHAVIOUR
2.1. ACTIVITY
The species is active from end April to half October [Peeters et al. 2004].
2.2. DEVELOPMENT
Nest
The females built their nests in rotting wood like tree stemms and tree trunks [Blösch 2000],[Michener 1971]. They gnaw the nests themselves or use old beetle tunnels that are extended [Michener 1971]. After 5-10 cm the main corridor branches into side corridors [Blösch 2000], which are about 3 to 5 cm deep. In each corridor there are no more than two brood-cellls [Michener 1971] that are filled with 12 to 25 prey specimen [Blösch 2000],[Michener 1971], usually with 16 [Blösch 2000]. When the brood-cell is filled one egg is positioned on one of the prey specimen [Bohart & Menke 1976]. In total the nest can contain 12-20 brood-cells [Blösch 2000].
Each brood-cell is closed with a plug of chewed wood [Blösch 2000],[Bohart & Menke 1976].
Development
The time for the small (1,2×0,3 mm) [Bohart & Menke 1976] white [Bohart & Menke 1976] eggs is unknown.
2.3. BEE HOTEL
The males can be found on and around the bee hotels. Regularly they will enter a nest hole and sit the opening looking out, and I suspect they use the hotel to sleep during the night.
The females nest in decayed wood and although they do show interest in the artificial nests I have yet to observe one use them. In 2020, three females had created their nests in a deep crack in the side of one of the nestblocks at ±2m height (section III, block 7). The wasps seemed to enter almost at the same spot but I think they had a different entrance although I have not been able to directly observe it.
Sawdust collected in a small mount at the entrance and on occasion a wasp would take a mouth full into the nest, presumably to plug a nest cell. The sawdust was transported using the jaws. I observed on occasion a wasp bringing prey home of an unidentified Cicadellidae.
One of the wasps was collected for identification.

2.4. MATING
Most Crabronidae females produce one generation per year [Kurczewski & Miller 1986].
2.5. HUNTING
The caught prey is transported belly-to-belly to the nest [Bohart & Menke 1976].
3. PLANT RELATIONS
3.1. WOOD
The following wood types are mentioned in literature as medium for the wasp to built her nests in:
Platanus (Plane) [Michener 1971] |
Prunus (Peach) [Bohart & Menke 1976] |
Quercus (Oak) [Michener 1971] |
Ulmus (Elm) [Michener 1971],[Formstone & Howe 2013] |
3.2. FOODPLANTS
The adult wasps feed with nectar. The following plants species and groups are mentioned in literature:
Umbellifers [Blösch 2000] (Apicaceae) | – |
4. PREY RELATIONS
The species does not have a prey preference [Klein 1999].
The following species and group occuring in the Netherlands [Soortenregister] are mentioned in literature:
Auchenorrhyncha (Cicadae) | Cicadellidae [Blösch 2000],[Lomholdt 1984] adults as well as nymphs [Kurczewski & Miller 1986] Alebra [Hamm & Richards 1926],[Bohart & Menke 1976] – Alebra albostriella [Michener 1971] Elymana – Elymana sulphurella [Blösch 2000] Edwardsiana – Edwardsiana rosae [Michener 1971] Empoasca [Bohart & Menke 1976] – Empoasca apicalis [Hamm & Richards 1926] – Empoasca fabae [Kurczewski & Miller 1986] Eupteryx – Eupteryx aurata [Blösch 2000] Eurhadina – Eurhadina concinna [Hamm & Richards 1926 ( als Eupteryx concinna )] Kyboasca – Kyboasca bipunctata [Michener 1971] Ossiannilssonola [Michener 1971] Ribautiana – Ribautiana ulmi [Hamm & Richards 1926 ( as Typhlocyba ulmi )] – Ribautiana tenerrima [Hamm & Richards 1926 ( als Typhlocyba tenerrima)] Typhlocyba [Michener 1971],[Bohart & Menke 1976] – Typhlocyba quercus [Hamm & Richards 1926] |
Diptera (Flies) [Ruchin & Antropov 2019] | – |
Hemiptera [Lomholdt 1984] | – |
Heteroptera (True bugs) | Meridae [Blösch 2000],[Lomholdt 1984] adults as well as nymphs [Kurczewski & Miller 1986] |
Psylloidea (Psyllids) | Psyllidae [Blösch 2000],[Lomholdt 1984] Psylla [Hamm & Richards 1926] |
Preyspecies outside the Netherlands:
– | – |
5. PARASITIC RELATIONS
The following species and groups occurring in the Netherlands [Soortenregister] are mentioned in literature:
– | – |
Parasitic species outside the Netherlands:
– | – |
6. IDENTIFICATION
Length males: 4,5 – 6 mm
Length females: 5 – 7 mm
Genus
Het genus Crossocerus can be recognized by the following characters:
1. Small to medium sized species, usually smaller than 10mm (here ±7 mm, female) [Bitsch et al. 2020],[Jacobs 2007]
2. Forewing: with one submarginal cell [Bitsch et al. 2020],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
3. Forewing: submarginal cell and discoidal cell separated by vein [Bitsch et al. 2020],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]

4. Forewing: length stigma shorter than length raidal cell [Klein 1999],[Dollfuss 1991], stigma narrow [Bitsch et al. 2020],[Dollfuss 1991]
5. Forewing: marginal cel truncate [Bitsch et al. 2020]
5. Hind wing: veins clear [Dollfuss 1991]
6. Thorax: dorsal side (mesonotum) smooth [Bitsch et al. 2020] or punctated (here punctated) [Jacobs 2007]
7. Thorax: side (mesopleuron) smooth or finely and widely spread punctated [Bitsch et al. 2020],[Jacobs 2007],[Dollfuss 1991] (here finely and widely spread punctated)
8. Thorax: side (mesopleuron) without precoxal keel (verticaulus) in front of middle coxa, at most with small protruding tooth [Bitsch et al. 2020],[Jacobs 2007] (here smooth)

9. Thorax: rear part side (metapleuron) entirely or partially smooth, at most finely striped (here entirely smooth) [Bitsch et al. 2020],[Jacobs 2007]

10. Thorax: propodeum without protrusions [Klein 1999],[Dollfuss 1991]
11. Thorax: dorsal field propodeum entirely or for most part smooth, at most very finely striped (here smooth) [Bitsch et al. 2020],[Jacobs 2007],[Dollfuss 1991]

12. Head: inner edge eyes strongly converging downwards [Bitsch et al. 2020],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
13. Head: inner edge eyes without indentations [Bitsch et al. 2020],[Klein 1999],[Dollfuss 1991]

14. Head: distance antenna base to inner edge eye smaller than antenna base diameter [Bitsch et al. 2020],[Jacobs 2007],[Dollfuss 1991]

15. Ocelli shaped in acute triangle [Bitsch et al. 2020],[Jacobs 2007],[Klein 1999],[Dollfuss 1991], or almost isosceles [Dollfuss 1991]

16. Abdomen: tergum 1 not petiolate [Bitsch et al. 2020],[Jacobs 2007]
17. Abdomen: length tergum 1 max 1,5x width apically [Bitsch et al. 2020],[Klein 1999],[Dollfuss 1991]
18. Abdomen: entirely black or with yellow markings (here entirely black) [Bitsch et al. 2020],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]





- Antenna with 12 segments [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
2. Abdomen with 6 segments [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
HEAD
1. Clypeus, frons [Bitsch 2021],[Klein 1999],[Dollfuss 1991] and inner edge eyes [Bitsch 2021],[Dollfuss 1991] black
2. Clypeus: with tow clear teeth [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
3. Mandible: apically with 3 teeth, inner edge usually without tooth (here without tooth) [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
4. Occipital carina: ending with spine [Dollfuss 1991]
THORAX
1. Pronotum: edges rounded [Bitsch 2021],[Jacobs 2007],[Dollfuss 1991]
2. Foreleg: base thigh front leg angular [Dollfuss 1991]
3. Foreleg: outer side tarsus member 1 front leg with clear thorn row [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
4. Propodeum: dorsal field limited by clear furrow [Bitsch 2021],[Klein 1999],[Dollfuss 1991]
5. Mesopleuron: without precoxal tooth [Bitsch 2021]
ABDOMEN
- Abdomen: black [Bitsch 2021], at most pygidium redbrown [Jacobs 2007],[Klein 1999],[Dollfuss 1991]
2. Terga 2 and 3: without restriction at the base [Bitsch 2021],[Jacobs 2007],[Dollfuss 1991]
3. Pygidium: with concave sides [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
4. Pygidium: glossy and with well defined frame, not 3-lobed [Jacobs 2007],[Klein 1999],[Dollfuss 1991]

5. Tergum 6: with some hairs next to pygidium [Jacobs 2007],[Dollfuss 1991]




1. Antenna: with 13 segments [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
2. Abdomen: with 7 segments [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
HEAD
1. Occipital carina: ending in clearly angular [Jacobs 2007], ending thornlike [Klein 1999], wide with clear tooth [Bitsch 2021],[Dollfuss 1991]
2. Antenna: last segment apically truncated [Bitsch 2021],[Jacobs 2007]
3. Clypeus black [11]
THORAX
1. Thorax: entirely black [Bitsch 2021],[Jacobs 2007]
2. Pronotum: sides without tooth [Dollfuss 1991]
3. Propleuron: toothed [Bitsch 2021]
4. Propodeum: dorsal field limited by furrow [Bitsch 2021],[Jacobs 2007],[Klein 1999]
5. Foreleg: shin (tibia) enlarged towards the tip, with erect bristles [Bitsch 2021],[Jacobs 2007]
6. Foreleg: tarsal member 1 enlarged and flattened, clearly wider than tarsal member 1 middle leg [Jacobs 2007]

7. Foreleg: tarsal member 1 widened, the next two members (2, 3) clearly widened and flattened [Bitsch 2021],[Jacobs 2007],[Klein 1999]

8. Foreleg: tarsal member 1 strongly enlarged, yellow with 2 to 3 darker spots [Bitch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
Shin (tibia) hind leg:
9. Black [Jacobs 2007]
10. Not enlarged
11. Outside often with clear and long thorns [Dollfuss 1991]
12. Foreleg: base trochanter and thigh (femur) front leg with angular protrusion [Dollfuss 1991]
ABDOMEN
1. Abdomen: entirely black [Bitsch 2021],[Jacobs 2007],[Klein 1999],[Dollfuss 1991]
2. Terga 2 and 3: without constriction at base [Jacobs 2007],[Dollfuss 1991]
Here there is a light constriction.
In case of constriction, in C. acanthophorus, there is a clear dorsal narrowing which makes tergite 1 look like it is humped, in lateral view.
3. Tergum 7 not stronger punctated than tergite 6 [Bitsch 2021],[Jacobs 2007],[Klein 1999]
Dollfuss [Dollfuss 1991]: Tergite 7 no visible punctation
Literature
Bitsch 2021 Bitsch, J., 2021. Hyménoptères sphéciformes d'Europe: Volume 2, Systématique (2e partie) : Crabroninae, Dinetinae, Eremiaspheciinae & Mellininae. France: Faune De France.Bitsch et al. 2020 Bitsch, J., Y. Barbier, S.F. Gayubo, H.-J. Jacobs, J. Leclercq, K. Schmidt., 2020. Hyménoptères sphéciformes d'Europe: Volume 1, Généralités, Heterogynaidae, Ampulicidae, Sphecidae, Crabronidae (1re partie). - France: Faune De France, 370p.
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.
Dollfuss 1991 Dollfuss, H., 1991. Bestimmungsschlüssel der Grabwespen Nord-und Zentraleuropas. Stapfia, 24, 1-247.
Formstone & Howe 2013 Formstone, B., & Howe, M., 2013. Brownfield sites and their value for invertebrates–A survey of selected sand quarries in north-east Wales in 2013: Borras Quarry and Marford Quarry. Cyfoeth Naturiol Cymru Natural Resources Wales, NRW Evidence Report No. 21
Hamm & Richards 1926 Hamm, A. H., & Richards, O. W., 1926. The biology of the British Crabronidae. Transactions of the Royal Entomological Society of London, 74(2), 297-331.
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.
Kurczewski & Miller 1986 Kurczewski, F. E., & Miller, R. C., 1986. Observations on some nests of Crossocerus (Blepharipus) a. annulipes (Lepeletier and Brullé)(Hymenoptera: Sphecidae).
Lomholdt 1984 Lomholdt, O., 1984. The Sphecidae (Hymenoptera) of Fennoscandia and Denmark. Fauna Entomologica Scandinavica, 4.1: 2.
Michener 1971 Michener, C. D., 1971. Notes on crabronine wasp nests. Journal of the Kansas Entomological Society, 44(3), 405-407.
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.
Ruchin & Antropov 2019 Ruchin, A. & Antropov, A., 2019. Wasp fauna (Hymenoptera: Bethylidae, Chrysididae, Dryinidae, Tiphiidae, Mutillidae, Scoliidae, Pompilidae, Vespidae, Sphecidae, Crabronidae & Trigonalyidae) of Mordovia State Nature Reserve and its surroundings in Russia. Journal of Threatened Taxa. 11. 13195-13250. 10.11609/jott.4216.11.2.13195-13250.
Soortenregister Nederlands Soortenregister
Waarneming.nl Waarneming.nl
Citation
Krischan, O.R., 2025. Crossocerus annulipes. Kerfdier, www.kerfdier.nl. Accessed on [date month year].