Ancistrocerus nigricornis ♀︎

Last update: 7 May 2020
SPECIES: Ancistrocerus nigricornis
GENUS: Potter wasps (ANCISTROCERUS)
FAMILY: VESPIDAE



OBSERVATION:
2020-V-202020-IV-212020-IV-202020-IV-192020-IV-052019-IX-15

YEARS:
20192020

MONTHS:
JanFebMarAprMayJunJulAugSepOctNovDec


Ancistrocerus nigricornis ♀︎, transporting mud

1. DISTRIBUTION

A. nigricornis is an uncommon wasp [2] that can be found throughout the Netherlands [2, 4].

2. BEHAVIOUR

2.1. ACTIVITY

The species is active from March to end of September [2].

The females are the only Ancistrocerus wasps that overwinter and are active early in the year starting in March before the other species are active  in May [5]. This makes them easy to identify during that period. the males die after mating in the autumn [5]. the females have mated last summer and are already ready to lay eggs [6].
As of June the new generation emerges.

2.2. DEVELOPMENT

A. nigricornis catches larvae of Leafroller moths (Tortricidae) [4,6].

Ancistrocerus nigricornis ♀︎, with prey

They nest in all kinds of bore holes, natural or artificial. In my bee hotels they are interested in nesting holes with a diameter of ±5 mm which is in compliance with the literature that states holes with a diameter of 4 – 5 mm [5].

The females are regular guests on the bee hotels, see also here.

3. BROOD PARASITES

The following A. nigricornis brood parasites  have been observed in the garden:

Wasps
(HYMENOPTERA)
Ruby-tailed wasp (Chrysis ignita) [4]

4. IDENTIFICATION

Length male 7,5 – 10,5 mm, length female 10 – 13 mm.

Females

Ancistrocerus nigricornis ♀︎

1. Legs yellow with black [3]

Ancistrocerus nigricornis ♀︎, legs yellow with black

2. Propodeum black [3]

Ancistrocerus nigricornis ♀︎, propodeum black
Ancistrocerus nigricornis ♀︎, propodeum black

3. Sternite 2 edge makes angle of ±90 degrees seen from the side, and flatly impressed behind it [3]

Ancistrocerus nigricornis ♀︎, edge sternite 2 straight angled, flat afterwards
Ancistrocerus nigricornis ♀︎, edge sternite 2 straight angled, followed by flat indentation

4. Tergite 1 normally with distinct marking [3]

Ancistrocerus nigricornis ♀︎, tergite 1 with characteristic yellow markings
Ancistrocerus nigricornis ♀︎, tergite 1 with characteristic yellow markings

5. Antenna scape underside yellow over entire length [3]

Ancistrocerus nigricornis ♀︎, antenna scape underside yellow

References

1 Nederlands Soortenregister

2 Waarneming.nl

3 MAUSS, Volker; TREIBER, Reinhold; SCHMID-EGGER, Christian. Bestimmungsschlüssel für die Faltenwespen (Hymenoptera: Masarinae, Polistinae, Vespidae) der Bundesrepublik Deutschland. DJN (Deutscher Jugendbund für Naturbeobachtung), 2004.

4 Martynova, Kate & Fateryga, Alexander. (2015). Chrysidid wasps (Hymenoptera, Chrysididae)—Parasites of eumenine wasps (Hymenoptera, Vespidae: Eumeninae) in Crimea. Entomological Review. 95. 472-485. 10.1134/S0013873815040090.

5 Breugel, P. van 2014. Gasten van bijenhotels. – EIS Kenniscentrum Insecten en andere ongewervelden & Naturalis Biodiversity Center, Leiden.

6 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.