1. DISTRIBUTION
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.
2. BEHAVIOUR
2.1. ACTIVITY
The species is active from beginning of May until the end of October [4].
2.2. DEVELOPMENT
She nests in boring holes, natural and artificial.
BEE HOTEL
The wssp uses artificial nesthelp and has a preference for:
– nest blocks higher than 2 meters [8]
– nest blocks with an orientation North or West (hypotheses), the species also uses nest blocks oriented South or East [8]
– nest holes with a diameter of 3-4 mm [8]
2.3. FOOD PLANTS
Adult S. crassicornis wasps feed on nectar and/or pollen. In literature the following plant species and groups are mentioned [5]:
| Apicaceae | Pastinaca sativa [6] |
3. PREY RELATIONS
The species is narrow oligophfagous on beetle larvae from the families of leafbeetles (CHRYSOMELIDAE) [4, 5] and snoutbeetles (CURCULIONIDAE) [4]. Also larvae of Tenthredinidae wasps are mentioned [4].
In literature the following species occurring in the Netherlands are mentioned:
| CHRYSOMELINAE | – Chrysomela populi [9] – Chrysomela saliceti [9] – Chrysomela lapponicum [9] – Plagiosterna aenea (Linaeidea aenea) [9] |
She finds her prey in all kinds of shrubbery and deciduous trees:
| Prey | Plant |
|---|---|
| Chrysomela populi | Populus tremula [4] |
| Chrysomela saliceti | Salix cinerea [4] |
| Plagiosterna aenea | Alnus incana [4] |
As far as I know none of these trees occurs in the garden’s vicinity.
4. PARASITIC RELATIONS
The following nest parasites of S. bifasciates are mentioned in literature:
| Wasps (HYMENOPTERA, CHRYSIDIDAE) | – Chrysis ignita [4,10] – Chrysis fulgida [4] |
The following nest parasites have been observed in the garden:
| Wasps (HYMENOPTERA) | – Chrysis ignita |
5. IDENTIFICATION
The male has a length of 10 -12 mm, the female 11 – 16 mm [2, 4].
Genus
The characteristics of the genus are [2,6,7]:
1. Tergite I with indentation and groove [2]
2. Ridge on tergite I well developed [2]
♀ & ♂
The characters of the species are [2,6,7]:
1. Tergite I with articulated punctation [2]
4. At least tergites I-IV with yellow band [6]
5. Tergite 2 within yellow band densely punctated [6]
6. Mesonotum and mesopleuron with wooly white hairs [2] (not visible in photos, probably already worn down, white hairs are visible)
7. Mesopleuron glossy and with wide spread punctuation [2,6]
8. Parapsidal furrow scutum from scutellem up to pronotum [2]
9. Large yellow spots on pronotum sides (P), and yellow spots on sides (mesopleuron, M), tegula (T) and scutellum (S) [2].
10. Cephalic foveae no larger than ocelle and separated more than space between ocellae [2]
11. Antennae scape with yellow spot [2]
12. Yellow spot above antennae implants [2]
12. Shins yellow, Shin I with black spot, legs II and III tarsi dark [7]
Females
♀
1. 12 antenna segments, 6 abdomen segments [2]
2. Clypeus female at least with yellow band [2]
♂
1. 13 antenna segments, 7 abdomen segments
2. Antenna segment 13 as long as wide
Literature
1 Nederlands Soortenregister2 SCHMID-EGGER, C. H. Bestimmungsschlüssel für die deutschen Arten der solitären Faltenwespen (Hymenoptera: Eumeninae). Deutscher Jugendbund für Naturbeobachtung, 1994, 54: 90.
3 Waarneming.nl
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 12. Die Gattung Symmorphus Wesmael 1836. na, 1999.
7 Albert de Wilde, Insecten fotosite ahw.me, Wespen
8 BUDRIENE, Anna. Reproductive ecology and behaviour of predatory wasps (Hymenoptera: Eumeninae). Doctor al thesis. Vilnius, 2004.
9 Budrienė, Anna. (2003). Prey of Symmorphus Wasps (Hymenoptera: Eumeninae) in Lithuania. Acta Zoologica Lituanica. 13. 306-310. 10.1080/13921657.2003.10512686.
10 PAERN, Madli, et al. Host specificity of the tribe Chrysidini (Hymenoptera: Chrysididae) in Estonia ascertained with trap-nesting. EJE, 2015, 112.1: 91-99.
