Artificial key

1 A large (>20 mm) brown and yellow species.....Vespa crabro

1' Usually a smaller wasp; either black with yellow or black with white.....2


2 (1') The wasp is black with white markings...... 3

2' The wasp is black with yellow markings...... 4


3 (2) First, second, and third gastral terga are all black, with out white markings. A large common species (>15 mm)..... D. maculata

3' First three gastral terga with white markings..... V. consobrina

[D. arctica, a parasitic black and white wasp will key out to this couplet.]
No image available at this time.


4 (2') Each compound eye of the wasp is completly surrounded by a yellow ring. A common species. (This character also works for queens).....V. pensylvanica

4' The compound eye is not surrounded by a yellow ring..... 5


5 (4') The upper side of the thorax has two prominent parallel longitudinal yellow lines near the center. (California, Southern Oregon, New Mexico, and Arizona)..... V. sulphurea

5' The upperside of the thorax is without two parallel yellow lines..... 6


6 (5') The bottom of the first antennal segment, the scape, is yellow underneath [V. norvegicoides keys out through this couplet, but I am not positive that the scape is yellow beneath.] .....7

6' The bottom of the first antennal segment, the scape, is black underneath.....10


7 (6) The genal area is continuos yellow, rarely broken by black. The rear edge of the first and second gastral terga are not continuous yellow, they are broken by black medially......D. arenaria

7' The genal area is continuous yellow or broken by black. The rear edge of the first and second gastral terga are continuous, not interrupted by black..... 8


8 (7') The genal area is broken by black, rarely continuous yellow. Rear middle region of the black area of gastral tergum 2 is rounded...... V. acadica

8' The genal area is continuous yellow or broken by black. Rear middle area of black region of gastral terga 2 is pointed.....9

or


9 (8') The genal area is broadly interrupted by black. The abdomen as pictured below.....D. norvegicoides

9' The genal area is not usually broken by black. The abdomen as pictured below......V. atropilosa


10 (6') The genal area is continuous yellow, usually not broken by black. Gastral tergum 2 usually with free black, or nearly free, spots. (In some melanic morphs, there are no free black spots)..... V. germanica

10' The genal area is broken by black, sometimes narrowly. Gastral tergum 2 without free black spots..... V. vulgaris


Page author: Matthew P. Kweskin kweskm@evergreen.edu
Last modified: 2 Feb 1997