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Western Yellowjacket - note folded wings, yellow eye loop, and feeding at nectary |
I know I tend to harp on this, but people seem to like to
view the world through simple dichotomies. Good and Bad Bugs is one such model.
So, to most, mosquitoes are bad bugs, ladybird beetles good bugs. Or if you are
of a more pedantic school of entomology, Hemiptera are good bugs and other
arthropods are not. Yellowjackets, hornets, and wasps probably tend to fall
into most people’s bad bug category because they can sting you and cause pain
and possibly death, as in this sad story of a man who bumped into a wasp nest
while taking a hike with his 13-year-old daughter in Queensland.
Wasps in the family Vespidae are those most likely to sting
you, but not all vespid wasps are equally quick to use their venom delivery
apparatus on something as large as a person. For example, the industrious
mud-dauber
Ancistrocerus waldenii that
I spent some time studying early in the summer never paid much attention to me,
even when my point-and-shoot was only a few centimeters above her. You can tell
she is a good vespid wasp by the fact she did not sting me and by the way the
front wings fold lengthwise when held at rest (in other wasp families, the
front wings are typically held flat).
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Mud-duber Ancistrocerus waldenii - a good wasp |
Other solitary vespids in the HBG go about their lives in an equally oblivious way, doing the things wasps like to do. If I get too close to them, they flee, although sometimes they have too much on their minds to do more than hang around. Mostly, though, we share the yard without a problem.
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Ancistrocerus parietum exploring the erotic potentials of dill |
On the other hand, worker yellowjackets in the Vespula vulgaris group are bad. They
invariably give me a buzz on their way through the yard. The Western
Yellowjacket (Vespula pensylvanica)
at the top is one of this group – the workers are pushy and aggressive. When I
swat at a wasp, I expect it to move on with alacrity – but these wasps respond
by buzzing around and getting in my face. This is especially true if I have
food or drink with me – they scavenge as well as hunt.
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Male Aerial Yellowjacket nectaring at goldenrod |
The taste for colas and
hambugers of the
vulgaris-group
species is not shared by other yellowjackets in my yard –those workers spend
most of their time hunting insects and males malinger on flowers. I guess that
makes them good, unless I bump into their nest.
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More black than yellow - Vespula alascensis male (note 7 abdominal segments) |
The
vulgaris-group
gets its name from the Common Yellowjacket
Vespula
vulgaris. This species used to be common here, but then taxonomists
discovered that
vulgaris was
restricted to Europe (and areas of the world into which it has been introduced
such as Australia and New Zealand). Our North American
vulgaris-like species is
Vespula
alascensis – smaller and darker than the Western Yellowjacket, but also
annoying. Being newly rediscovered (it was actually described in 1870),
V. alascensis lacks a common name
(BugGuide gives it none). The ‘More Black than Yellowjacket’ would be
descriptive of its looks and the ‘Lesser Annoying Yellowjacket’ would describe
its behaviour well enough.
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Hi, I have no common name - Vespula alascensis male |
One interesting aspect of the HBG the last couple of warm
weeks (now replaced by cold, wet) was the number of male yellowjackets.
Although the males can’t sting, and so I guess are good, I still sent about two
dozen to science heaven. Almost a third were
V. alascensis – although none annoyed me. Actually, they were very
unobtrusive, other than wanting drinks from around the edge of the pond. They
don’t seem to be interested in nectar, wine, or even barbecues. I guess they
must have gotten fed enough as youngsters in the nest to last out the autumn.
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13-segmented antennae identify a male - scape, pedicel, and 11 flagellomeres |
Most of the rest of the males were the Western Yellowjacket
(
Vespula pensylvanica). This was no
surprise – the few annoying yellowjacket workers around this summer were
V. pensylvanica. Unlike the workers,
these males are entirely innocuous and seem to be mostly interested in landing
on lawn or low vegetation and then crawling to the ground. I find this
behaviour mysterious, but those I followed around did nothing more exciting
than lap up water.
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From its yellow eye loop, a Western Yellowjacket (and male) |
Two of the males, though, were yet another
vulgaris-group species,
Vespula
germanica, a recent colonist from Europe. Apparently the common name now
used is German Yellowjacket – which seems unfair to the Germans and a poor descriptor
of a more widely distributed European species. Since the German Yellowjacket is expanding its
range in North America, technically it must be an invasive species; and
therefore, even the males must be bad.
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A doubly bad German Yellowjacket - well, at least the eye loop is absent |
As far as I can tell, the German Yellowjackets are no worse
that the Western Yellowjacket, but they are hard to tell apart. The best field
character is the colour around the eyes: the yellow around the eyes of
germanica is absent at the top of the eyes, but in
pensylvanica it is usually present.
Usually, but not always, so like most dichotomies, this is a bit more
complicated than it should be.
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7-spotted Ladybeetle - 6 US states have designated this beetle
their state insect - but it is an invasive species; and therefore, bad. |
Nice collection of wasp photos, and you're really becoming quite deft with that point and shoot!
ReplyDeleteHmm, yes, this point-and-shooter is getting better at documenting medium to large insects, but the colours are definitely not as crisp as those from Mrs HBG's Nikon and the backgrounds more cluttered and distracting.
ReplyDelete