Last update: 3 January 2020
SPECIES: Symmorphus crassicornis


Symmorphus crassicornis ♀︎


S. crassicornis is a rare wasp in the Netherlands and is found especially in the east, middle and south of the country [1, 4].

The species visited the garden in 2019.



The species is active from April until end October [4].


S. crassicornis is monophagous on Chrysomaelidae and curculionidae beetles [4, 5]. She finds her prey in all kinds of shrubbery and deciduous trees.

She nests in boring holes, natural and artificial.


The male has a length of 10 -12 mm, the female 11 – 16 mm [2, 4].

The characteristics of the species are [2,6,7]:

1. Tergite I with indentation and groove
2. Ridge on tergite I well developed
3. Tergite I with articulated punctuation

Symmorphus crassicornis ♀︎, tergite I with indentation and groove, and well developed ridge

4. At least tergites I-IV with yellow band

Symmorphus crassicornis ♀︎, yellow bands on tergites I – IV and sternites II – IV

5. Mesonotum and mesopleuron with wooly white hairs (not visible in photos)
6. Mesopleuron glossy and with wide spread punctuation

Symmorphus crassicornis ♀︎, mesopleuron glossy with large and widely separated punctuation

7. Parapsidal furrow scutum from scutellem up to pronotum

Symmorphus crassicornis ♀︎, parapsidal furrows scutum from scutellem up to pronotum

8. Cephalic foveae no larger than ocelle and separated more than space between ocellae

Symmorphus crassicornis ♀︎, cephalic foveae not larger than ocelle

9. Clypeus female at least with yellow band
10. Antennae scape with yellow spot

Symmorphus crassicornis ♀︎, yellow band on clypeus and yellow spot on antenna scape

11. Shins yellow, Shin I with black spot, legs II and III tarsi dark [7]

Symmorphus crassicornis ♀︎, yellow shins, shin I with black spot, legs II and III tarsi dark


The following parasites on S. crassicornis are present in the garden:



1 Nederlands Soortenregister

2 SCHMID-EGGER, C. H. Bestimmungsschlüssel für die deutschen Arten der solitären Faltenwespen (Hymenoptera: Eumeninae). Deutscher Jugendbund für Naturbeobachtung, 1994, 54: 90.


4 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.

5 Budrienė, Anna. (2003). Prey of Symmorphus Wasps (Hymenoptera: Eumeninae) in Lithuania. Acta Zoologica Lituanica. 13. 306-310. 10.1080/13921657.2003.10512686.

6 GUSENLEITNER, J. Bestimmungstabellen mittel-und südeuropäischer Eumeniden (Vespoidea, Hymenoptera) Teil 1: Die Gattung Leptochilus SAUSSURE 1852. na, 1993.

7 Albert de Wilde, Insecten fotosite, Wespen