Symmorphus
crassicornis ♀︎

Last update: 3 July 2020
SPECIES: Symmorphus crassicornis
GENUS: SYMMORPHUS
FAMILY: VESPIDAE



OBSERVATION:
2020-V-202019-VI-01

YEARS:
20192020

MONTHS:
JanFebMarAprMayJunJulAugSepOctNovDec


Symmorphus crassicornis ♀︎

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]:

ApicaceaePastinaca 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:

CHRYSOMELINAEChrysomela 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:

PreyPlant
Chrysomela populiPopulus tremula [4]
Chrysomela saliceti Salix cinerea [4]
Plagiosterna aeneaAlnus 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]

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

♀ & ♂

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

1. Tergite I with articulated punctation [2]

Symmorphus crassicornis ♀︎, tergiet 1 duidelijk gepuncteerd

4. At least tergites I-IV with yellow band [6]

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

5. Tergite 2 within yellow band densely punctated [6]

Symmorphus crassicornis ♀︎, tergiet 2 binnen gele band dicht gepuncteerd

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]

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

8. Parapsidal furrow scutum from scutellem up to pronotum [2]

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

9. Large yellow spots on pronotum sides (P), and yellow spots on sides (mesopleuron, M), tegula (T) and scutellum (S) [2].

Symmorphus crassicornis ♀︎, gele vlekken op pronotum (P), mesopleuron (M), tegula (T) en scutellum (S)

10. Cephalic foveae no larger than ocelle and separated more than space between ocellae [2]

Symmorphus crassicornis ♀︎, cephalic foveae not larger than ocelle


11. Antennae scape with yellow spot [2]
12. Yellow spot above antennae implants [2]

Symmorphus crassicornis ♀︎, yellow spot on antenna scape, yellow spot above antennae implant

12. 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

Females

1. 12 antenna segments, 6 abdomen segments [2]
2. Clypeus female at least with yellow band [2]

Symmorphus crassicornis ♀︎, yellow band on clypeus

1. 13 antenna segments, 7 abdomen segments
2. Antenna segment 13 as long as wide


References

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.

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 1: Die Gattung Leptochilus SAUSSURE 1852. na, 1993.

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.