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YELLOWJACKETS & HORNETS THROUGH A LENS

INTRODUCTION
An earlier version of this report used the taxonomy of Akre et al. 1981.
"The Yellowjackets of America North of Mexico".
Since then there have been several changes in the nomenclature.
Bob Jacobson kindly provided the following updated nomenclature
including the various common names being applied to the species.

CLASSIFICATION
Subfamily Vespinae- Hornets and Yellowjackets

Genus Vespa
crabro
Linnaeus - European Hornet

Genus Dolichovespula
Dolichovespula norwegica
(Fabricius) - Norwegian Wasp, Norwegian Yellowjacket,
................Arctic Hornet or Arctic Yellowjacket (was albida)
Dolichovespula adulterina (du Buysson) - Parasitic Yellowjacket
................or Parasitic Hornet (was arctica)
Dolichovespula arenaria (Fabricius) - Common Aerial Yellowjacket or Common Yellow Hornet
Dolichovespula maculata (Linnaeus) - Baldfaced Hornet
Dolichovespula norvegicoides (Sladen) - Northern (or Canadian) Aerial Yellowjacket
................or Northern (or Canadian) Yellow Hornet
Dolichovespula alpicola Eck - Rocky Mountain Aerial Yellowjacket
.................or Rocky Mountain Yellow Hornet (or just Mountain A. Y. or Mountain Y. H.) (was saxonica)

Genus Vespula
The rufa group:

Vespula acadica (Sladen) - Forest Yellowjacket, Polka-dot Yellowjacket
Vespula atropilosa (Sladen) - Prairie Yellowjacket
Vespula consobrina (de Saussure) - Blackjacket
Vespula rufa (Linnaeus) - Northern Red-Banded Yellowjacket (was intermedia)
Vespula vidua (de Saussure) - Ground Hornet

Vespula austriaca (Panzer) - Cuckoo Yellowjacket
not in following key but similar to Vespula acadica
Queen

Vespula squamosa (Drury) - Southern Yellowjacket
Vespula sulphurea (de Saussure) - California Yellowjacket

The vulgaris group

Vespula flavopilosa Jacobson - Downy Yellowjacket (or perhaps Mountain Yellowjacket)
Vespula germanica (Fabricius) - German Yellowjacket
Vespula maculifrons (du Buysson) - Eastern Yellowjacket
Vespula pensylvanica (de Saussure) - Western Yellowjacket
Vespula vulgaris (Linnaeus) - Common Yellowjacket or Canadian Yellowjacket


Members of the genus Vespula are generally ground nesters,
those of Dolichovespula are aerial nesters, i.e., exposed nests above ground.
The European Hornet, Vespa usually makes its nest in hollow trees, barns, attics,
and hollow walls of houses.


Note 1: the gaster (6 segments in females,7 in males) is the main part of
the body behind the narrow waist. It consists of abdominal segments 2-7 in
females, 2-8 in males. The first abdominal segment has become fused to the
thorax, thus the waist is actually between the 1st and 2nd abdominal segments.
The dorsal surface of each segment is called a tergum (pl. terga) or urotergite.
The males' 13-segmented antennae are longer than the females' 12-segmented antennae.

Note 2: click on a thumbnail to see an enlarged image and descriptive text.

THE MAIN CHARACTERS FOR IDENTIFICATION INCLUDE:

- Presence of a vertical yellow line (pronotal carina) on the thorax immediately behind the head.
Found in members of the genus Dolichovespula but absent in Vespula; see comments
here: and here
Note: this yellow pronotal carina line is not always evident in all specimens of Dolichovespula;
thus its presence defines a Dolichovespula species but its absence is not conclusive of a
Vespula species.

- size of gap between the compound eye and the mandible (the oculo-malar space) - wide in the genus
Dolichovespula, narrow in the other 2 genera

- also note, in above image, the colour of ventral surface of the 1st antennal segment (the scape)-
black or yellow;
- and the face pattern (also in above image) - usually pale with a mid-dorsal patch of variable size;

- pattern of the pale band (genal band) behind the eye - varies from complete to
being notched:
HERE
or widely interrupted in the middle so as to give dorsal and ventral components
HERE;

- extent of the pale genal band - may extend to above the compound eye to join up
with pale spot on front of head to form a complete ring around the eye
;

- shape of pale stripe on dorso-lateral surface of thorax;

- pattern on dorsal surface of thorax (scutum) - 2 thick yellow stripes
HERE
or no stripes
HERE;

- pattern of pale and dark markings on gaster (‘abdomen’); pale markings can vary from
white to pale yellow to intense yellow; may have reddish spots;
- number of ‘abdominal’ segments - 6 in females, 7 in males;

- number of antennal segments - 12 in females, 13 in males;
as seen in above image

- note that the 3 castes (queen, worker, males) may differ significantly in pattern
within a species.

KEY TO SPECIES

- BLACK & WHITE/PALE YELLOW SPECIES:

>>>>>>>>>>go to [A]


- BLACK & YELLOW/ORANGE SPECIES:

>>>>>>>>>>go to [2]


[2]
- THORAX and 1st TERGITE with REDDISH BROWN PATCHES

EUROPEAN HORNET
Vespa crabro
>>>>>>>>>>go to [B]

- THORAX and 1st TERGITE LACKING REDDISH BROWN PATCHES
>>>>>>>>>>go to [3]


[3]
- THORAX WITH 2 WIDE YELLOW STRIPES DORSALLY

>>>>>>>>>>go to [C]


- THORAX WITHOUT 2 WIDE YELLOW STRIPES DORSALLY
>>>>>>>>>>go to [4]


[4]
- COMPLETE YELLOW RING AROUND TOP OF EYE

Western Yellowjacket
Vespula pensylvanica
>>>>>>>>>>go to [D]

- NO COMPLETE RING AROUND EYE
>>>>>>>>>>go to [5]


[5]
- 2nd ABDOMINAL SEGMENT MOSTLY BLACK BUT WITH 2 YELLOW SPOTS
COMPLETELY SURROUNDED BY BLACK


>>>>>>>>>>go to [E]


- 2nd SEGMENT NOT AS ABOVE
>>>>>>>>>>go to [6]


[6]
- ABDOMEN WITH AT LEAST 1 PAIR OF ISOLATED BLACK SPOTS,
i.e., not connected to any black part of segment


>>>>>>>>>>go to [F]


- ABDOMEN WITH NO ISOLATED BLACK SPOTS,
may be spots but these connected to other black areas


>>>>>>>>>>go to [G]


========================================

[A] BLACK & WHITE SPECIES:
Parasitic Yellowjacket, Baldfaced Hornet, Blackjacket,
Arctic Yellowjacket, Northen Red-banded Yellowjacket


PARASITIC YELLOWJACKET Dolichovespula adulterina
Queens.................................................Males
....
Queens and Males


BugGuide Info Page: HERE

BALDFACED HORNET Dolichovespula maculata
Queens

Workers

Males

Queens, Workers, Males


BugGuide Info Page: HERE

BLACKJACKET
Vespula consobrina
Queens.........................................................Workers
......
Males

Queens, Workers, Males


BugGuide Info Page: HERE

ARCTIC YELLOWJACKET Dolichovespula norwegica
Worker


NORTHERN RED-BANDED YELLOWJACKET Vespula rufa (was intermedia)
Worker



====================================

[B]- THORAX and 1st TERGITE with REDDISH BROWN AREAS:
EUROPEAN HORNET Vespa crabro
All castes



=====================================

[C]- THORAX BLACK, DORSALLY with 2 LARGE YELLOW STRIPES
Southern Yellowjacket, California Yellowjacket
C1 Found east of the Rocky Mountains
SOUTHERN YELLOWJACKET Vespula squamosa
All castes



C2 Found west of the Rocky Mountains
CALIFORNIA YELLOWJACKET Vespula sulphurea
No images in BugGuide

=======================================

[D]- COMPLETE YELLOW RING AROUND TOP OF EYE
Western Yellowjacket Vespula pensylvanica
Queens

Workers


=======================================

[E]- 2nd ABDOMINAL SEGMENT MOSTLY BLACK BUT WITH
2 YELLOW SPOTS COMPLETELY SURROUNDED BY BLACK

Forest Yellowjacket, Prairie Yellowjacket
FOREST YELLOWJACKET Vespula acadica
Queens

Workers

PRAIRIE YELLOWJACKET Vespula atropilosa
no images in Guide

=======================================

[F]- ABDOMEN WITH AT LEAST 1 PAIR OF ISOLATED BLACK SPOTS
Common Aerial Yellowjacket, Common Yellowjacket;
Downy Yellowjacket, Eastern Yellowjacket,
German Yellowjacket, Ground Hornet


- Anterior Black Mark on 1st Tergite Interrupts the
posterior yellow band
>>>>[F1]

- Anterior Black Mark on 1st Tergite almost identical
to
[F1] but NOT Interrupting the posterior yellow band>>>>[F2]

- Anterior Black Mark on 1st Tergite Anchor-shaped>>>>[F3]

- Anterior Black Mark on 1st Tergite Diamond-shaped
>>>>[F4]

- 2 Elongated Yellow Dots on 1st Segment, 2nd segment
mostly Black
>>>>[F5]

[F1]
COMMON AERIAL YELLOWJACKET Dolichovespula arenaria
Queens


----------------------------------------------

[F2]
COMMON YELLOWJACKET Vespula vulgaris
Queens


DOWNY YELLOWJACKET Vespula flavopilosa
Queens


---------------------------------------------

[F3]
EASTERN YELLOWJACKET Vespula maculifrons
Queens


---------------------------------------------

[F4]
GERMAN YELLOWJACKET Vespula germanica
Queens.......Workers................Males
......

---------------------------------------------

[F5]
GROUND HORNET Vespula vidua
Queens..................................................Workers
........
Males


============================================

[G]- ABDOMEN LACKING ISOLATED BLACK SPOTS
>>>>[G1]

[G1]
[ - Anterior black band on tergite 1 with 2 concavities that form
a posterior-pointing median extension that divides the yellow band(top figure)

>>>>[G2]

- Anterior black band either almost straight or with 2 concavities,
but the median point does not divide the yellow band (bottom figure)

>>>>[G3]



- Anterior black mark on 1st tergite Anchor-shaped
>>>>[G4]

- Anterior black mark on 1st tergite Diamond-shaped
>>>>[G5]

- Anterior black mark on 1st tergite broadly V-shaped
>>>>[G6]

- 1st tergite black but with 2 yellow spots anteriorly
>>>>[G7]

[G2]
COMMON AERIAL YELLOWJACKET Dolichovespula arenaria
Workers

Males


-----------------------------------------------------

[G3]
NORTHERN AERIAL YELLOWJACKET Dolichovespula norvegicoides
Queens...............Workers............Males
........

COMMON YELLOWJACKET Vespula vulgaris
Some Workers..............................Males
......

-----------------------------------------------------

[G4]
EASTERN YELLOWJACKET Vespula maculifrons

Workers



Males


NOTE Eastern Yellowjacket Queens have isolated black spots on adbominal segments.

----------------------------------------------------

[G5]
COMMON YELLOWJACKET Vespula vulgaris
some workers


DOWNY YELLOWJACKET Vespula flavopilosa
some males


WESTERN YELLOWJACKET Vespula pensylvanica
some males


----------------------------------------------------

[G6]
DOWNY YELLOWJACKET Vespula flavopilosa
workers

males


----------------------------------------------------

[G7]
GROUND HORNET Vespula vidua
males


8888888888888888888888888888888888888888888888888888

Basically finished, I will add new images and species as they are posted.
I believe we have made great progress since the inception of this project on 2 April 2005.
I would like to acknowledge, with thanks, Troy - of course - and the following for their photo contributions:
Alex, Troy Bartlett, Patrick Coin, Stephen Cresswell, Nicky Davis, Tony DiTerlizzi, Ted Edwards,
Vincent Hickey, Bill Johnson, Kildale, Richard Leung, Charles Schurch Lewellen,
Bruce Marlin, Kerry Matz, Jo McGavin, Robin McLeod, Beatriz Moisset, Tom Murray,
John Racette, David Reed, Matthew Roth, Sasc, Lew Scharpf, Lynette Schimming,
Scott Taylor, Tony Thomas, Urtica, Richard Vernier, Andy Wehrle, Bev Wigney, Chris Wirth.

Richard Vernier, Bob Jacobson, Eric Eaton among others, added valuable comments.

Basically Finished
A comment to update the date in the Forums!

 
Nice job!! Looks great. Howev
Nice job!! Looks great. However, I still think that's actually a worker in photo 19005 that you have under "males" in D. arenaria. Also, somebody has posted what I believe to be V. pensylvanica males in ID request.

 
Sincere Apologies
I meant to change this after your e-mail; in fact I thought I had. I never doubted your diagnosis. Now corrected. Thanks
I laboured over that recent male submission. My inclination was towards a Western but was hoping that someone with experience of this species would make an ID. Akre et al indicate that workers of this species may not have a complete ring around the eye: "Usually with a continuous ring dorsally around......."

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