Crossocerus annulipes♀︎♂︎

Last update: 8 June 2023


SPECIES: Crossocerus annulipes




Official name


Crossocerus annulipes [1]

Blepharipus annulipes
Blepharipus ambiguus
Coelocrabro ambiguus
Crabro ambiguus

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Latin: having a ring-shaped foot

Crossocerus annulipes ♂︎


1. Distribution
2. Behaviour
3. Plant relations
4. Prey relations
5. Parasitic relations
6. Identification


Crossocerus annulipes is an uncommon wasp [2] that occurs spread throughout the Netherlands [3,9] , but is not present in meadows and polder areas, and on the wadde islands [9].



The species is active from end april to half october [3].



The females built their nests in rotting wood like tree stemms and tree trunks [4,5]. They gnaw the nests themselves or use old beetle tunnels that are extended [5]. After 5-10 cm the main corridor branches into side corridors [4], which are about 3 to 5 cm deep. In each corridor there are no more than two brood-cellls [5] that are filled with 12 to 25 prey specimen [4,5], usually with 16 [4]. When the brood-cell is filled one egg is positioned on one of the prey specimen [14]. In total the nest can contain 12-20 brood-cells [4].
Each brood-cell is closed with a plug of chewed wood [4,14].


The time for the small (1,2×0,3 mm) [14] white [14] eggs is unknown.


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.

Crossocerus annulipes ♀︎, entering nest in side bee hotel nest block
Crossocerus annulipes ♀︎, leaving nest


Most Crabronidae females produce one generation per year [8].


The caught prey is transported belly-to-belly to the nest [14].


3.1. WOOD

The following wood types are mentioned in literature as medium for the wasp to built her nests in:

Platanus (Plane) [5]
Prunus (Peach) [14]
Quercus (Oak) [5]
Ulmus (Elm) [5,13]


The adult wasps feed with nectar. The following plants species and groups are mentioned in literature:

Umbellifers [4]

Garden species

The garden contains some umbellifers but I have not yet observed the species on them.


The species does not have a prey preference [9].
The following species and group occuring in the Netherlands [1] are mentioned in literature:


Cicadellidae [4,12]
adults as well as nymphs [8]

Alebra [6,14]
– Alebra albostriella [5]

Elymana sulphurella [4]

Edwardsiana rosae [5]

Empoasca [14]
Empoasca apicalis [6]
Empoasca fabae [8]

Eupteryx aurata [4]

Eurhadina concinna [6 ( as Eupteryx concinna ) ]

Kyboasca bipunctata [5]

Ossiannilssonola [5]

Ribautiana ulmi [6 ( as Typhlocyba ulmi )]
Ribautiana tenerrima [6 ( as Typhlocyba tenerrima ) ]

Typhlocyba [5,14]
Typhlocyba quercus [6]
(Flies) [7]
Hemiptera [12]
(True bugs)

Meridae [4,12]
adults as well as nymphs [8]


Psyllidae [4,12]
Psylla [6]

Garden species

None of the mentioned prey species have been observed yet in the garden but there are many Cicadellidae and Meridae.


I have not found any literature references to nest parasites that also occur in the Netherlands.


Length males: 4,5 – 6 mm
Length females: 5 – 7 mm


Het genus Crossocerus can be recognized by the following characters:

1. Small to medium sized species, usually smaller than 10mm (here ±7 mm, female) [10]

2.  Front wing with one submarginal cell [9,10,11]

Crossocerus annulipes ♂︎, Crossocerus: front wing with 1 submarginal cell

3. Front wing submarginal cell and discoidal cell separated by vein [9,10,11]

Crossocerus annulipes ♂︎, Crossocerus: front wing submarginal cell and discoidal cell separated by vein

4. Length stigma shorter than length raidal cell [9,11], stigma nnarrow [11]

Crossocerus annulipes ♂︎, Crossocerus: length stigma (ls) shorter than length radial cel (Lr)

5. Veins hind wing clear [11]

Crossocerus annulipes ♀, Crossocerus: veins hind wing clear

6. Dorsal side thorax (mesonotum) smooth or punctated (here punctated) [10]

Crossocerus annulipes ♀, Crossocerus: mesonotum smooth or punctated (here punctated)

7. Side thorax (mesopleuron) smooth or finely and widely spread punctated [10,11] (here finely and widely spread punctated)

Crossocerus annulipes ♀, Crossocerus: mesopleuron smooth or finely and widely punctured

8. Side thorax (mesopleuron) without precoxal keel (verticaulus) in front of middle coxa, at most with small protruding tooth [10] (here smooth)

Crossocerus annulipes ♀, Crossocerus: mesopleuron without precoxal carina, at most with a prominent point (here smooth)

9. Rear part side thorax (metapleuron) entirely or partially smooth, at most finely striped (here entirely smooth) [10]

Crossocerus annulipes ♀, Crossocerus: metapleuron entirely or partially smooth, at most finely striped (here smooth)

10. Propodeum without protrusions [9,11]
11. Dorsal field propodeum entirely or for most part smooth, at most very finely striped (here smooth) [10,11]

Crossocerus annulipes ♀, Crossocerus: propodeum without protrusions and entirely or partialy smooth, at most finely striped (here smooth)

12. Inneredge eyes stronly converging downwards [9,10,11]
13. Inneredge eyes without indentations [9,11]

Crossocerus annulipes ♂︎, Crossocerus: inner edge eyes strongly converging downwards, eyes without emargination

14. Distance antenna base to inneredge eye smaller than antenna base diameter [10,11]

Crossocerus annulipes ♂︎, Crossocerus: distance antennal socket to edge eye shorter than diameter antennal socket

15. Ocelli shaped in acute triangle [9,10,11], or almost isosceles [11]

Crossocerus annulipes ♀, Crossocerus: ocellen vormen scherpe gelijkzijdige driehoek, of bijna gelijkzijdig

16. First abdominal segment not petiolate [10]

Crossocerus annulipes ♀, Crossocerus: first abdominal segment not petiolate

17. Length first abdominal tergite max 1,5x width apically [9,11]

Crossocerus annulipes ♀, Crossocerus: length tergite 1 max 1,5x width apically

18. Abdomen entirely black or with yellow markings (here entirely black) [9,10,11]

Crossocerus annulipes ♀, Corssocerus: abdomen entirely black or with yellow spots (here entirely black)

Crossocerus annulipes ♀︎
Crossocerus annulipes ♀︎
Crossocerus annulipes ♀︎
Crossocerus annulipes ♀, Crossocerus: propodeum without protrusions and entirely or partialy smooth, at most finely striped (here smooth)

  1. Antenna with 12 segments [9,10,11]
Crossocerus annulipes ♀︎

2. Abdomen with 6 segments [9,10,11]

Crossocerus annulipes ♀︎, abdomen with 6 segments


1. Clypeus, frons [9,10] and inner edge eyes [11] black

Crossocerus annulipes ♀︎, clypeus, frons and inneredge eyes black

2. Clypeus with tow clear teeth [9,10,11]

Crossocerus annulipes ♀︎
Crossocerus annulipes ♀︎

3. Mandible apically with 3 teeth, innere edge usually without tooth (here without tooth) [9,10,11]

Crossocerus annulipes ♀︎

4. Occipital carina ending with spine [11]

Crossocerus annulipes ♀︎, end occipital carina pointed


1. Pronotum edges rounded [10,11]

Crossocerus annulipes ♀︎, pronotum corners rounded

2. Base thigh front leg angular [11]

Crossocerus annulipes ♀︎, base thigh front leg angular

3. Outside tarsus member 1 front leg with clear thorn row [9,10,11]

Crossocerus annulipes ♀︎, outside tarsus member 1 front leg with clear thorn row

4. Dorsal field propodeum limited by clear furrow [9,11]

Crossocerus annulipes ♀︎, dorsal field propodeum limited by clear furrow


  1. Abdomen black, at most pygidium redbrown [9,10,11]
Crossocerus annulipes ♀︎, abdomen black, at most pygidium redbrown

2. Tergite 2 and 3 without restriction at the base [10,11]

Crossocerus annulipes ♀︎, tergite 2 and 3 basally not restricted

3. Pygidium with concave sides [9,10,11]
4. Pygidium glossy and with well defined frame, not 3-lobed [9,10,11]

Crossocerus annulipes ♀︎, pygidium glossy with scharp pronounced edges and concave sides, not 3-lobed

5. Tergiet 6 with some hairs next to pygidium [10,11]

Crossocerus annulipes ♀︎, tergite 6 has some hairs adjacent to pygidium

Crossocerus annulipes ♂︎
Crossocerus annulipes ♂︎
Crossocerus annulipes ♂︎
Crossocerus annulipes ♂︎
Crossocerus annulipes ♂︎, propodeum

  1. Antenna with 13 segments [9,10,11]
Crossocerus annulipes ♂︎, antenna with 13 segments

2. Abdomen with 7 segments [9,10,11]

Crossocerus annulipes ♀, abdomen with 7 segments


1. Occipital carina ending in clearly angular [10], ending thornlike [9], wide with clear tooth [11]

Crossocerus annulipes ♂︎, occipital carina ends in clear angle

2. Final antennal segment apically truncated [10]

Crossocerus annulipes ♂︎, last antennal segment truncated

3. Clypeus black [11]


1. Thorax entirely black [10]

Crossocerus annulipes ♂︎, thorax entirely black

2. Pronotum sides without tooth [11]

Crossocerus annulipes ♂︎, pronotum sides without teeth

3. Dorsal field propodeum limited by furrow [9,10]

Crossocerus annulipes ♂︎, propodeum dorsally limited by furrow

4. Shin (tibia) front leg enlarged towards the tip, with erect bristles [9,10]

Crossocerus annulipes ♂︎, tibia 1 enlarged towards tip, with sidewards pointing hair bristles

5. Tarsal member 1 frint leg enlarged and flattened, clearly wider than tarsal member 1 middle leg [10]

Crossocerus annulipes ♂︎, tarsus member I front leg enlarged and flattened, clearly wider than middle leg tarsus member 1

6. Tarsal member 1 front leg widened, the next two members (2, 3) clearly widened and flattened [9,10]

Crossocerus annulipes ♂︎, Tarsus member 1 front leg enlarged, next two members (2, 3) clearly enlarged and flattened

7. Tarsal member front leg strongly enlarged, yellow with 2 to 3 darker spots [9,10,11]

Crossocerus annulipes ♂︎, tarsus member 1 front leg enlarged, yellow with 2 or 3 dark spots

Shin (tibia) hind leg:
8. Black [10]
9. Not enlarged
10. Outside often with clear and long thorns [11]

Crossocerus annulipes ♂︎, tibia hind leg black, not thickend, outside often with long thorns

11. Base trochanter and thigh (femur) front leg with angular protrusion [11]

Crossocerus annulipes ♂︎, base trochanter (t) and femur (f) front leg with angular protrusion
Crossocerus annulipes ♂︎, femur front leg with angular protrusion


1. Abdomen entirely black [9,10,11]
2. Tergites 2 and 3 without constriction at base [10,11]

Here there is a light contriction.
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.

Crossocerus annulipes ♂︎, tergites 2 and 3 without basal narrowing

3. Tergite 7 not stronger punctated than tergite 6 [9,10]
[DOLLFUSS]: Tergite 7 no visible punctation [11]


1 Nederlands Soortenregister


3 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.

4 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.

5 MICHENER, Charles D. Notes on crabronine wasp nests. Journal of the Kansas Entomological Society, 1971, 44.3: 405-407.

6 Hamm, A. & Richards, O.. (2009). The biology of the British Crabronidae. Transactions of the Royal Entomological Society of London. 74. 297 - 331. 10.1111/j.1365-2311.1926.tb02241.x.

7 Ruchin, Alexander & Antropov, Alexander. (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.

8 KURCZEWSKI, F. E.; MILLER, R. C. Observations on some nests of Crossocerus (Blepharipus) A. Annulipes (Lepeletier and Brulle)(Hymenoptera: Sphecidae). Proceedings of the Entomological Society of Washington, 1986, 88.1: 157-162.

9 KLEIN, Wim. De graafwespen van de Benelux. Jeugdbondsuitgeverij, Utrecht, 1996, 1-130. + KLEIN, Wim. De graafwespen van de Benelux: supplement. Jeugdbondsuitgeverij, 1999.

10 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.

11 Hermann Dollfuss, "Bestimmungsschlüssel der Grabwespen Nord- und Zentraleuropas (Hymenoptera, Sphecidae) mit speziellen Angaben zur Grabwespenfauna Österreichs", Publikation der Botanischen Arbeitsgemeinschaft am O.Ö.Landesmuseum Linz, LINZ, 20. Dezember 1991

12 LOMHOLDT, O. 1975-1976; 1984 (2. Auflage). The Sphecidae (Hymenoptera) of Fennoscandia and Denmark. Fauna Entomologica Scandinavica, 4.1: 2.

13 FORMSTONE, Bryan; HOWE, Mike. Brownfield sites and their value for invertebrates–A survey of selected sand quarries in north-east Wales in 2013: Borras Quarry and Marford Quarry.

14 Bohart, R.M. & A.S. Menke, 1976. Sphecid wasps of the world: a generic revision. - University of California Press, 695 p.

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