European beewulf ♀︎♂︎

Last update: 19 June 2022
SPECIES: European beewulf (Philanthus triangulum)
GENUS: PHILANTHUS
FAMILY: CRABRONIDAE (Digger wasps)



OBSERVATION:
2022-VI-032021-VIII-062021-VIII-052021-IX-062021-IX-052020-VIII-282020-VIII-242020-VIII-212020-VIII-092020-IX-042019-VIII-302019-VIII-162016-VII-17

YEARS:
20162019202020212022

MONTHS:
JanFebMarAprMayJunJulAugSepOctNovDec




UPDATE: Added identification photo's, updated text

3. IDENTIFICATION

Official name:

Synonyms:

Philanthus triangulum [1]


see more on: www.gbif.org

Etymology:

triangulum

Philanthus triangulum ♂︎

CONTENTS

1. Distribution
2. Behaviour
3. Plant relations
4. Prey relations
5. Parasitic relations
6. Identification

1. DISTRIBUTION

Philanthus triangulum is a common species in the Nederland [2,3].

Garden species

Since 2019 the wasp is present in the garden every year. At the end of the day males often appear to dig a sleeping place in the sand. Females are attracted to the garden by the presence of Honeybees (Apis melifera) in the garden. On one occasion a female started digging extensively but never finished the nest.

2. BEHAVIOUR

2.1. ACTIVITY

The species is active from end of May up to the beginning of October [1].

2.2. DEVELOPMENT

Nest

Nests are dug in sandy ground [6], sometimes in aggregations [6].

The nests can consist of 3 to 34 cells [3], 3 to 6 prey specimen are used per cell [3].

2.3. BEE HOTEL

The species does not make use of artificial nest help, not for nesting nor for sleeping.

2.4. HUNTING

The female hunts actively on Honey bees (Apis melifera).

Her hunting method follows a few steps:

  1. First she’ll fly a couple of times around the plant to observe the potential victims
  2. When she has found a victim she will drop down on her from flight
  3. In the following skirmish she’ll sting the victim to paralyse her
  4. After that she will hold the bee between her legs and jaws until it stops resiting.

In a personal observation I observed step 4 turned out to be difficult resulting in the prey to fall to the ground. These seemed to be accidents and not on purpose. After the prey had fallen to the ground she had no longer interest in it. After some days several paralysed or dead bees were lying under the plant where they were foraging and captured.

The venom of the species has a permanent paralysing effect on the bees [12].

Honey bee ♀︎ (Apis mellifera), dead victim of European beewulf

3. PLANT RELATIONS

3.1. FOOD PLANTS

The following plant species are mentioned in literature as food sources:

Apiaceae
(Umbellifers)

Falcaria
Falcaria vulgaris (Sickelweed) [5]
Asteraceae
(Composite family)

Cirisium (Plume thistles) [5]

Tanacetum

Tanacetum vulgare (Tansy) [5]
Ericaceae
Calluna [5]
Lamiaceae
Thymus (Thyme) [5]
Onagraceae
(Willowherb family)

Epilobium (Willowherbs) [5]
Rhamnaceae
(Buckthorn family)

Rhamnus (Buckthorns) [9]
Rosaceae
(Rose family)

Rubus (Blackberry) [5]

Garden species

I’ve seen the species forage in the garden on the following plants:

Asteraceae
(Composite family)

Solidago (Goldenrod) [5]
Lamiaceae
Mentha
Mentha suaveolens (Apple mint)

4. PREY RELATIONS

The larvae are fed with Honey bees (Apis melifera).

European beewulf ♀︎ (Philanthus triangulum)

With high exception bees from other genera are used as well [3,7]:

  • Andrena (Mining bees)
  • Dasypoda
  • Halictus (Sweat bees)
  • Lasioglossum (Sweat bees)
  • Megachile (Leafcutter bees)

5. PARASITIC RELATIONS

The following species and groups occurring in the Netherlands [1] are mentioned in literature:

Chrysididae
(Cuckoo wasps)

Chrysis
Chrysis ignita [7]

Heydychrum
Heydychrum gerstaeckeri [5,7]
Heydychrum rutilans [5,7]

Pseudomalus
Pseudomalus auratus [7]

Diptera
(Flies)

Conopidae [5]
Conops [3]

Sarcophagidae [5]
Metopia [3]
Metopia argyrocephala [5]
Metopia leucocephala [7]

Physocephala
Physocephala chrysorrhoea [5,7]
Physocephala vittata [5,7]

Senotainia
Senotainia albifrons [7]

Sphecapata [3]
Sphecapata conica [5,7]

Parasitic species outside the Netherlands:

Coleoptera
(Beetles)

Dermestidae [7]

Dermestes
Dermestes murinus [7]
Mutilididae
(Velvet ants)

Dasylabris
Dasylabris maura [7]
Diptera
(Flies)

Sarcophagidae


Phylloteles
Phylloteles pictipennis [7]

6. IDENTIFICATION

Length males: 13 – 17 mm
Length females: 8 – 10 mm

Genus

The genus Philanthus can be recognised by the following characteristics:

1.  Forewing: with 3 submarginal cells [9,10,11]

European beewulf ♀︎ (Philanthus triangulum), forewing with 3 submarginal cells

2. Forewing: submarginal cell 3 not petiolate or triangular [9,10,11]

European beewulf ♀︎ (Philanthus triangulum), Philanthus: submarginal cell 3 not petiolate or triangular

3. Forewing: first discoidal transvers vein joins submarginal cell 2 [9,11], second discoidal transvers vein joins submarginal cell 3 [9,10,11]

European beewulf ♀︎ (Philanthus triangulum), Philanthus: second discoidal transvers vein joins submarginal cell 3

4. Head: Inner edge of the eye with indentation [9,10,11]

European beewulf ♀︎ (Philanthus triangulum), inner edge eye with indentation

5. Notauli: short and unclear [10,11]

Philanthus triangulum ♂︎, Philanthus: notauli short and unclear

6. Propodeum: upper side densely punctuated and haired [10,11]

European beewulf ♀︎ (Philanthus triangulum), dense punctuation and hairs on propodeum

7. Abdomen: tergite 1 not petiolate [9,10,11]

Philanthus triangulum ♂︎, Philanthus: abdomen not petiolate

8. Abdomen: tergites with yellow spots [9,10,11]

European beewulf ♀︎ (Philanthus triangulum), tergites with yellow spots


European beewulf ♀︎ (Philanthus triangulum)
European beewulf ♀︎ (Philanthus triangulum)
European beewulf ♀︎ (Philanthus triangulum)

1. Antenna with 12 segments [9,10,11]

European beewulf ♀︎ (Philanthus triangulum), antenna with twelve segments

2. Abdomen with 6 segments [9,10,11]

Bijenwolf ♀︎ (Philanthus triangulum), achterlijf met zes segmenten

3. Abdomen without pygidium [11]

European beewulf ♀︎ (Philanthus triangulum), abdomen without pygidium

4. Clypeus: without long hairs [10,11]

European beewulf ♀︎ (Philanthus triangulum), clypeus without long hairs

5. Foreleg: tarsus with tarsal comb [9]

European beewulf ♀︎ (Philanthus triangulum), tarsus frontleg with tarsal comb

KOP

1. Clypeus: front edge clypeus with two teeth [10,11]

European beewulf ♀︎ (Philanthus triangulum), teeth on clypeus

2. Head: red curved elongated spot behind the eye. The color is very variable [5].

European beewulf ♀︎ (Philanthus triangulum), red rounded elongated spot behind eye

THORAX

ABDOMEN



specimen caught for photo identification on 10-vi-2022

Philanthus triangulum ♂︎
Philanthus triangulum ♂︎
Philanthus triangulum ♂︎
Philanthus triangulum ♂︎
Philanthus triangulum ♂︎

1. Antenna with 13 segmenten [9,10,11]

European beewulf ♂︎ (Philanthus triangulum), antenna with thirteen segments

2. Abdomen with 7 segments [9,10,11]

European beewulf ♂︎ (Philanthus triangulum), abdomen with seven segments

3. Clypeus: with long hairs [10]

European beewulf ♂︎(Philanthus triangulum), clypeus with long haris and triangular shape on frons

HEAD

1. Forehead (frons): with triangular crown shaped yellow spot [9]

European beewulf ♂ (Philanthus triangulum), face with crownshaped yellow spot

2. Head: yellow colored rounded long spots behind the eye. The color is very variable [5]

European beewulf ♂ (Philanthus triangulum), yellow spot behind eye

THORAX

ABDOMEN



References

1 Nederlands Soortenregister

2 Waarneming.nl

3 Peeters, T.M.J., H. Nieuwenhuijsen, J. Smit, F. van der Meer, I.P. Raemakers, W.R.B. Heitmans, C. van Achterberg, M. Kwak, A.J. Loonstra, J. de Rond, M. Roos & M. Reemer 2012. De Nederlands bijen (Hymennoptera: Apidae s.l.). - Natuur van Nederland 11, Naturalis Biodiversity Center & European Invertebrate Survey - Nederland, Leiden.

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