Ectemnius cavifrons

Last update: 24 January 2020
SPECIES: Ectemnius cavifrons
GENUS: ECTEMNIUS
FAMILY: Digger wasps (CRABRONIDAE)



OBSERVATION:
2019-VII-22

YEARS:
2019

MONTHS:
JanFebMarAprMayJunJulAugSepOctNovDec


Ectemnius cavifrons ♂︎

1. DISTRIBUTION

Ectemnius cavifrons is a less common wasp that can be found throughout the Netherlands [3].

2. BEHAVIOUR

2.1. ACTIVITY

The species is active from half April to end September [4].

2.2. DEVELOPMENT

Nests are made in dead wood. Hoverflies (Syrphidae) are used as food for larvae [4]

3. IDENTIFICATION

It is a mid sized wasp. Length male 8-12,5 mm, female 11-16,5 mm [4].

There are a large number of Diggerwasps (CRABRONIDAE) that look similar and are difficult to differentiate [4].

The characteristics of the genus Ectemnius are [2]:

1. One submarginal cel in front wing

Ectemnius cavifrons ♂︎, one submarginal cel in frontwing

2. Ocelli shaped in obtuse triangle
This characteristic apparently does not apply to E. cavifrons because they are shped in a acute triangle.

Ectemnius cavifrons ♂︎, ocelli make obtuse triangle in Ectemnius, this does not seem to be true for E. cavifrons

3. Mesopleuron wrinkled

4. Mesopleuron with short keel in front of middle coxa (the connecting segment of the leg to the thorax)

6. Abdomal tergites smooth, most species have fine punctuation to leathery matt, some exception with coarse puctuation

7. Males with 12 antennal segments

Ectemnius cavifrons ♂︎, antenna male with 12 segments

 

The main characteristics of the species are [2]:

Males

1. Antenna 3 with clear teeth
2. No hairbrush on teeth
3. Teeth on antenna segements 4 and 5 equally large as teeth on segment 3

Ectemnius cavifrons ♂︎, teeth on antenna segments 4 and 5 smaller than on segment 3

4. Vertex completely indentated around ocelli

Ectemnius cavifrons ♂︎, vertex completely indentated around ocelli

5. Tarsus 5 front leg strongly enlarged

Ectemnius cavifrons ♂︎, tarsus 5 strongly widened

6. Basal tarus middle leg from inside outwards widened with maximum width before the tip

Ectemnius cavifrons ♂︎, basal tarsus diverges widest before the tip

7. Back edge tergite 7 rounded smoothly progressing into side
8. No teeth on mandible inner edge
9. Front femora without tooth
10. Clypeus hairs golden colored


References

1 Nederlands Soortenregister

2 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

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 Albert de Wilde, Insecten fotosite ahw.me, Wespen

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