You
could spend your your whole life studying wasps and never feel like you knew but a small
part of the world of wasps. The topic "wasps" is enormous!First of all, to the non-specialist, the boundary between what's a wasp, a
bee, and even an ant (all members of the Hymenoptera) isn't at all clear. The many
families at first glance seem to blend into one another. Moreover, the people who gave
insects their English names were not specialists. For example, Velvet Ants are actually
wingless wasps.
Here are some
of the most commonly noticed wasp families:
- SPIDER WASPS (Family
Pompilidae)
- prey: spiders
- nest: in ground or made of mud
- PAPER OR VESPID
WASPS (Family Vespidae)
- Paper Wasps (subfamily Polistinae)
- prey: various insects
- nest: papery, circular tier of cells
attached by a short stalk
- Yellowjackets & Hornets (subfamily Vespinae)
- prey: various insects
- nest: papery cells surrounded by covering,
in or aboveground
- Potter Wasps (subfamily Eumeninae)
- prey: usually caterpillars
- nest: burrows in ground or natural cavities,
or made of mud
- SPHECID WASPS (Family
Sphecidae)
- Thread-waisted Wasps
(subfamily Sphecinae)
- prey: grasshoppers, caterpillars or spiders,
depending on tribe
- nest: in ground or made of mud
- Organ-pipe Mud-daubers (subfamily Trypoxyloninae)
- prey: spiders
- nest: tubular nests of mud, or in natural
cavities
WASP VIDEOS
If your computer is equipped
with the Flash video player, or you're willing to download the player for free, check out
Dick Walton's free online
videos of various kinds of Solitary Wasps at important moments in
their lifecycles. |
A while back, living in southwestern Mississippi, I ran into
an extremely aggressive "paper wasp" I wasn't able to identify. One day I made
contact with a real wasp specialist, Dr. Joy Layton, who figured out that the aggressive
wasp was a Paper Wasp of the genus Polistes. Dr. Layton told me a good bit about Polistes
and I include that information below just so you can see the kind of stuff that can be
known about a randomly selected wasp species that just happens to be around you:
There are many temperate zone Polistes
species. Among the Polistes everybody dies in late fall/early winter EXCEPT the
new queens. They mated with males of their species in September/October, often swarming
around fields of blooming goldenrods and other wildflowers. This is the only time of year
that you'll find males, and they look a lot like the females, only that their antennae are
more curved and their faces tend to have lighter colors.
The mated queens then seek hibernation sites,
which tend to be protected, but cool enough to keep the queens dormant so that they don't
use up their stored body fat. Often young queens crawl into crevices in the eaves of
buildings, go too far in and get inside somebody's house, then they fly around and get
mashed by the human occupants! If they find the right spot, they just stay dormant until
spring.
In early spring they fly out, feed on nectar
from whatever flowers are in bloom and start a small paper nest. It is almost always one
queen with one nest- no sharing! Each early-season nest is tiny and usually overlooked by
humans. These young queens are usually rather timid and docile -- their best strategy
being to remain unobserved and nonaggressive until they can raise their first generation
of offspring to be the workers that will expand the nest, forage for food and protect the
colony.
A spring wasp nest is small and completely
unprotected while the new queen is off foraging for food for her larvae. She must feed
them on caterpillars she's captured and butchered. Her larvae are helpless, legless white
grubs which look nothing like a wasp. After about three to four weeks, these grubs pupate
and emerge as new workers. They are all female and all sterile. Besides, there are no
males alive to mate with anyway, so these workers will not lay eggs but will devote their
lives to raising the next set of eggs of the queen.
In other words, the queen has raised the first
brood to be a bunch of old maids who will devote themselves to raising their younger
sisters. These workers too tend to be relatively docile. They are small and while they
will protect the nest if they have to they don't go looking for trouble. The queen no
longer leaves the nest, but keeps laying eggs as the workers expand the nest and forage
and feed the larvae and the queen.
The next set of larvae that mature will also
probably be sterile workers. But somewhere around the 3rd or 4th set of larvae (called
"broods") the females that emerge are larger and bolder. They may still be
sterile workers but they are more aggressive.
By now, it is late summer and this is when
people suddenly notice the wasp nests on the eaves of their porch and declare that they
"just sprung up overnight!" Of course the colony has been there all along but
now it is bustling and much more apparent. July and August are when the colonies usually
reach these aggressive proportions. Workers on these late summer nests are much more
willing to jump off the nest and attack you just because you're in their space- and their
perception of that space has expanded.
You can stand within a couple of feet of a
spring/early summer nest and the workers will not fly at you. They'll watch you, orienting
themselves to keep their eyes on you, but usually that is all. But the workers of those
same nests in late summer will spring off the nest at the mere approach of a human and
sting! And they may go off looking for trouble even far away from the nest.
The set of larvae that these aggressive workers
are raising will emerge as young queens and males. The virgin queens look just like the
workers, maybe a little larger, but not always. Males I've described. The virgin queens
don't forage or build the nest but usually just hang out until time to fly off and find
mates. There seems to be no mating going on on the nest (which would be between sisters
and brothers) but only off in the fields of wildflowers of the season, a good way to avoid
inbreeding.
After the virgin queens and males fly off, the
colony declines, fewer eggs/larvae are present and the old queen dies either before cold
weather or the first frost or so. The workers die. The nest is empty and deserted, never
to be reused.
Then it all repeats.
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