Bald-faced Hornet

(1) Species Similar To Bald-faced Hornet: Three other yellowjackets that are basically black and white can be confused with the Baldfaced Hornet. These are: White Yellowjacket (or called Arctic Yellowjacket) (D. albida), Northern Yellowjacket (or called Parasitic Yellowjacket) (D. arctica), and the Blackjacket (V. consobrina). Queens of the latter 2 species are compared with a Baldfaced queen (Fig M). One difference between the Baldfaced and the other 3 species is that in the former segment 2 is always all black (Fig N lateral view of the 3 castes of the Baldfaced Hornet)), in the other 3 there is a pale band on the posterior of segment 2.
The syrphid fly: Spilomyia fusca is a mimic of the Bald-faced Hornet.   buggudie.net

(2) Dolichovespula norwegica (Norwegian wasp, a species of eusocial wasp from northern Europe) and Dolichovespula albida (the Arctic yellowjacket from northern North America) are considered to be the same species but studies of the male genitalia show that they are not conspecific.  wiki-1

(3)
Bald Faced Hornet queen and male
src: http://www.biology.ualberta.ca/bsc/ejournal/bmc_05/key_dolichovespula.html

(4) copy from 2011 log

Bald-faced Hornet (Dolichovespula maculata) - Bald-faced Hornets are predators and they attack only live prey. They are mostly predators of spiders, harvestmen, hemipterans, spittle bugs, house flies, sawflies larvae, caterpillars, beetles, other yellowjackets species and grasshoppers. The adults carry their prey or part of them to the nest to feed their larval states. They sometimes feed of flower nectar or sweet substances (Akre et al. 1981, VanDyk 2003).   src

(5) Notes On Yellow jackets As A Food Source For The Bald Faced Hornet Vespula maculata

J O Howell
Entomological News 84: 141-142 (1973)   src

page 141: http://biostor.org/cache/20571/entomologicalnew84amer_0165.jpg     mirror

page 142: http://biostor.org/cache/20571/entomologicalnew84amer_0166.jpg     mirror  

(6) Is this a Bald-faced Hornet?
Calgary/Weaselhead flats, Alberta, Canada
May 15, 2008

http://bugguide.net/node/view/183807/bgpage

No - but a MUCH better finding!

For this is actually a queen of the Arctic (aerial) Yellowjacket, Dolichovespula norwegica albida. This is the first live specimen in BG, for we had only a dry pinned worker provided by Dr Buck until now. Most reproductive females lack lateral red spots on T2.Thank your for sharing this pic! I ignored this subspecies of Old-World D. norwegica occured as far South as Calgary, but the Rockies have something to do with that.
By the way, current name of the Bald-faced Hornet is Dolichovespula maculata.

Q:  I thought that Yellowjackets are black/yellow?

Four North-American Yellowjackets (and,for that matter, several Eastern Asian ones, especcially in Japan), have white or whitish, instead of yellow, color patterns.
Interestingly, the Western Palaearctic counterparts of V. rufa intermedia, D. norwegica albida and D. adulterina arctica have yellow patterns.

(7) "I thought this was the same species (Bald faced hornet) that I had posted a few days ago. Today I noticed that it has an extra white band and wondered if this was something a little different. ID and any info would be appreciated. Thanks"  src

Male Dolichovespula maculata
Yes, males of the baldfaced hornet occasionally have this extra white band of T-1. I have never seen a worker or queen with this marking. A couple specimens I have show a slight trace of a band on T-2, but in each case the bands are much more developed on T-1 and on T-3 through T-7. The only specimens having large bands on each tergite, including T-2, are probably victims of chilling or other misfortune during development (as evidenced by their deformed wings!).

By the way, this species occasionally has thoracic stripes suggestive of those of Vespula squamosa.

Bald Faced Hornet (Dolichovespula maculata) - male
Indeed a color variant of this species, in that the apical band on the 1st (uro)tergite is especially broad. Most often there are only two faint, whitish stripes at the same place, just like here on the 3rd tergite - this latter having, generally, only small lateral spots. Note that only males can have such a special, somewhat confusing, color pattern. But, the 2nd tergite always remains all black, which occurs in no other species (V. consobrina. D. arctica, both being likely to occur in your region [Victoria, British Columbia, Canada]).

(8) Oak Sap : I guess you took this picture at the same place as the European Hornet V. crabro? It shows that both species have very similar feeding habits, being very fond of tree sap - what kind of tree, by the way: maybe an Oak (Quercus)?. Although being phylogenically an aerial Yellowjacket, the Bald faced Hornet is very close, ecologically speaking, to true Hornets.  bugguide.net (Bald-faced Hornet worker)

(9) Baldfaced Hornet - Queen

(10) Bald-faced Hornet infosrc   mirror

But Yellowjacket workers kill prey by biting, not stinging.

(11) Bald-faced Hornet x Brooklyn Botanic Garden x nest - "They typically nest high in trees, or large shrubs like the Lilac above [at Brooklyn Botanic Garden]. Sheltered by summer foliage, and camouflaged the color the bark, they're difficult to spot."