Wasp Facts: History, Habitats and Habits

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PHOTO: FOTOLIA/BJONESPHOTOGRAPHY
Friendly or fierce? Bad or beneficial? When it comes to these summertime residents, both fear and beauty are in the eye of the beholder.

An introduction to the wasp, learn more wasp facts including the history of the wasp, food sources, habits and habitats of wasps.

Wasp Facts: History, Habitats and Habits

My earliest memories include the time my big brother pushed
me out of the hayloft onto a cement floor, the summer
morning I toddled off a pier and nearly drowned, and The
Day The Wasp Stung Me. I can still recall my
terror–overwhelming as only a small child’s can
be–when the wasp landed on the inside of my shirt
collar. Maybe three years old at the most, I took off
running pell-mell across the barnyard toward our house,
screaming, flailing at the insect. Naturally it stung me. I
swatted some more, and it stung me again. By the time my
father reached me and brushed the wasp away, my neck and
shoulder were dotted with a half-dozen painful red
swellings. Luckily, I’ve never been sensitive to wasp
venom, and after a few days of soreness and itching the
bites faded away.

Not so the memory. Just as the hayloft incident taught me
to think twice before turning my back on my big brother,
and falling off the pier gave me a lesson in the difference
between bath water and deep water, the wasp stings left a
lasting impression. It was a good thing, too, because when
you’re a boy growing up on a dairy farm, keeping your
distance from wasps and hornets is almost as essential as
keeping your feet out of cow pies. But I was more than just
wary of wasps. I spent most of my young life in compulsive
fear of them–and of nearly any insect that looked or
even sounded like a wasp. I was convinced that
their sole purpose was to attack and sting people (me in
particular).

It was only years later, when my interests in nature and
the outdoors forced me to come to grips with my fear, that
I learned otherwise. Wasps are among the most maligned of
all living creatures. They play extraordinary, fascinating
roles in nature. As a group, they’re the single most
effective natural control of earth’s agricultural and
household insect pests. And though it’s true that more
people die each year from wasp and bee stings than from the
bites of all other venomous creatures, it’s also true that
wasps and bees are far more mild-mannered than commonly
believed, and seldom sting without cause.

For that matter, of the 2,500 or so species of wasps known
to inhabit North America, only about 50 can sting at all.
What we call a stinger is actually a modified ovipositor,
the hollow tube through which female insects deposit eggs.
Most wasps use the instrument for that purpose alone. Some
species employ the tube to bore holes into tree bark or
other vegetable matter in which to lay eggs. Others, such
as trichogrammas, the gardeners’ allies against cabbage
loopers and corn borers, inject eggs into the bodies or
larvae of other insects. Only a relative handful of wasps
are also capable of injecting venom through their
ovipositors, and thus a painful sting. But even of these,
virtually all are mild-mannered loners, solitary wasps that
ordinarily keep their distance from man and use their
venom-loaded hypodermics only to stun spiders, caterpillars
or other insects with which to provision their nests.
Except when mating, they live their lives alone.

Mud Daubers

Probably the most familiar of solitary wasps are the mud
daubers, which (OK, it’s obvious) build their homes with
mud. Chances are you’ve seen the lumpy, dried-mud nests of
the black-and-yellow mud dauber (scientifically and
appropriately named (Sceliphron caementarium) or
the tidier, parallel-tube architecture of the organ pipe
wasp (Trypoxylon politum). Both species gather
mud from the banks of puddles and pools by rolling the clay
into pea-size pellets and flying it, one pellet at a time,
to a suitable homesite–usually a house or barn wall,
a rafter or the eave of a roof. There, spreading mud in
overlapping semicircles and buzzing heartily as she works
(only females build nests), the wasp plasters together a
hollow, tubular cell. As soon as she completes a cell she
flies off in search of a spider, paralyzes it with a sting
(wasps never use their stingers to kill prey
except in self-defense), then grasps it between her jaws
and forelegs and flies home. The mud dauber then shoves the
stunned insect (or sometimes several of them) into the
cell, lays a single egg in the compartment, closes it off
and proceeds to build and stock other cells beside or on
top of the first. Most dauber nests contain from six to 20
cells, although much larger nests have been recorded.

Once all the cells have been stocked and an egg laid in
each, the wasp covers the nest with an outer layer of clay
and leaves for good. Soon white, grublike larvae hatch from
the eggs and feast on the paralyzed spiders. A few days
later, the well-fed larvae spin cocoons in which they
pupate, or develop into adult insects. The transformation
takes about three weeks, after which each mature wasp chews
a small hole in the wall of its cell and flies away to
mate. All wasps go through this four-stage
process–egg, larva, pupa and adult. As you may
remember from biology class (or from Invasion of the
Body Snatchers
), this is called complete
metamorphosis
.

The mud dauber’s tendency to build nests on man-made
structures and its peculiar habit of buzzing loudly as it
works are unfortunate. For those reasons alone, countless
nests end up crushed under the butt end of a broomstick or
soaked in insecticide. Too bad, because mud daubers are
among the meekest of wasps–you virtually have to pick
one up and squeeze it to make it sting–and are
effective predators of household spiders. One species, in
fact–the blue mud dauber (Chal-byion
califomicum
)– specializes in capturing black
widow spiders. (This dauber is also known as the blue
burglar for its habit of breaking into other dauber nests,
tossing out all the larvae and spiders.) Other types of
daubers prey on cabbage loopers and other garden pests. In
short, mud daubers are good wasps to have around.

Paper Wasps

The creatures most of us think of when we think “wasp” are
the social, or paper, wasps: the hornets, yellow jackets
and other species that build oval, papery nests in which
hundreds or even thousands of individual insects live and
work cooperatively, much like bees in a hive.

If you’re ever at a gathering of entomologists and the
party gets dull, ask someone in a loud voice what the
differences are between hornets and yellow jackets (species
of the genus Vespula). Confusion reigns over the
distinctions between members of the two groups–to the
point where the names are used interchangeably. For the
sake of discussion, some naturalists have settled on the
essentially arbitrary distinction that yellow jackets build
their nests underground or concealed in walls, while
hornets (which some scientists assign to a more specialized
genus, Dolichovespula) build pear-shaped, aerial
nests suspended above ground. It’s as good a compromise as
any, though in actual fact the wasps seem not to have the
distinction down either, and sometimes build in the “wrong”
place. Still, the general rule is hornets above, yellow
jackets beneath.

The most common hornets in North America are the bald-faced
hornet (Vespula maculata) and the sandhill
hornet (Vespula arenaria). Maculata is
a large (one to one-and-a-half inches long), black species
with a distinctive white pattern on its face and body.
Arenaria is somewhat smaller (about an inch long)
and less widely distributed, and has yellow and black
stripes (it’s often called a yellow jacket). Both types
generally build their characteristic globular paper nests
in the open, in bushes, trees and on buildings. The
bald-faced hornet’s nest can become the size of a bushel
basket, and the sandhill’s may reach the proportions of a
soccer ball. The larger the nest, the more aggressively
they defend it (this is true of all paper wasps).

Separate yellow jacket species are almost impossible to
identify by appearance–they’re all about one-half to
one inch long, and are yellow-and-black striped–but
their nesting habits are distinct. The eastern yellow
jacket (Vespula maculifrons) and the western
yellow jacket (V. pennsylvanica) build nests in
the ground, often in the abandoned burrows of moles or
other animals, or at ground level in brush piles or hollow
logs.

Although you can’t see them, the nests are much like hornet
nests, consisting of several horizontal tiers of
honeycomblike cells all enclosed in a paper sheath. The
entrance hole to such a nest may be no larger than a
quarter, but the nest itself can be as big as, or bigger
than, a bald-faced hornet’s. Another yellow jacket species,
Vespula germanica, builds equally large nests
inside the walls of buildings.

Generally speaking, yellow jackets have nastier tempers
than other paper wasps, but they are not the maddened
winged terrorists so many people make them out to be, and
seldom sting, as is often heard, “at the least
provocation.” The real trouble with yellow jackets is that
you can’t see the nest until you’ve blundered across it,
either stepping on the entrance or running over it with a
tractor or lawn mower. Wall-nesting germanica
yellow jackets are similarly hazardous, because they tend
to chew away the plasterboard and insulation in a wall
until only a paper-thin barrier remains between the nest
and the inside of the building. Pity the unsuspecting
homeowner who, upon hearing a buzzing and scraping inside a
wall, knocks on the surface to locate the source–only
to put his fist into a mass of yellow jackets.

The third major group of common paper wasps encompasses a
number of similar-looking species all belonging to the
genus Polistes. Depending on where you live,
these slender, hard-bodied wasps may be brown, rust-colored
or black, or they may have yellow or black stripes. They
build relatively simple nests consisting of a single,
unenclosed comb suspended from a short stem. Because their
nests have no roof or walls, Polistes wasps build
their homes where they’ll be out of the rain–under
shed roofs, inside double-hung windows, beneath eaves.
Polistes wasps are the gentlest of paper wasps and
seldom attack unless provoked. They can inflict a
painful sting, though–it was a Polistes that
injected the fear of wasps into my toddler-size neck many
years ago.

Wasp Facts: The Life Cycle

Though each type has its idiosyncrasies, yellow jackets,
hornets and Polistes wasps have similar life histories.
Except in tropical regions, paper wasp communities are
single-season affairs. Each is begun in spring by a female
that, the previous fall, mated with one or more males and
then spent the winter hibernating in a protected
place–often beneath the bark of a tree or log, or
between boards in an attic or basement. When the queen
emerges from hibernation in the spring, she dines on flower
nectar to restore her strength, then selects a nesting site
and begins to build. She collects fibers from old boards,
branches, fence posts and other sources, pulling up the
pieces with her jaws and chewing and mixing them with
saliva to form a small pellet of
papier-mâchê-like pulp. Then she flies back to
the nest site, where she spreads the pellet out to form a
paper-thin layer. Shuttling back and forth, gathering
material and returning to apply it, she builds the
foundation and a few shallow cells.

The queen lays an egg in each cell, and as she lays each
egg, she also releases a sperm cell from the supply that
she’s carrier in her body since she mated the previous
fall. A few days later, the fertilized eggs hatch and the
queen feeds the larvae bits of chewed-up insects. She
continues providing the grubs with a bug burger diet for
the next week to three weeks–after which the larvae
spin cocoons and transform into pupae. A week to three
weeks later, they emerge as adults.

The first brood of the season, and most of the subsequent
broods, are sterile females, workers who take over nest
building and all other duties except egg laying, which
becomes the queen’s only job. In her single-season
lifetime, a queen hornet or yellow jacket may lay as many
as 25,000 eggs.

By July and August, paper wasp nests are . . . well, a
beehive of activity. The population of a hornet or yellow
jacket nest may number in the thousands. (Polistes colonies seldom exceed several hundred.)
Workers busily shuttle back and forth, some delivering
chewed-up prey to larvae while others work to expand the
nest. On hot days, some workers fan the nest with their
wings, and sometimes even carry water from puddles and
pools and sprinkle it on the cell walls to keep the colony
cool. At its peak, a mature colony of paper wasps, with
hundreds or thousands of individuals working together,
driven to cooperation by eons of evolved instinct, seems
like one solitary creature–a pulsating paper organism
with a single purpose and a hundred thousand legs.

But by late summer, for reasons not entirely understood,
the society begins to deteriorate. More and more pupae
emerge as males or fertile females rather than as sterile
female workers. The reproductive wasps take little part in
caring for the colony, and gradually the remaining workers
lose interest in the larvae and abandon them, or sometimes
even feed on them. The queen, exhausted, dies. Eventually,
all the males and fertile females leave the nest to mate.
The workers remain but, left with little strength, perish
one by one. The males, too, die after mating. In the end,
only the reproductive females, each already carrying the
live sperm that will produce next season’s colonies,
survive to hibernate and perpetuate the cycle.

Wasps, it seems, like so many other creatures branded
“dangerous” by man, are only struggling to survive,
following the tyranny of their genes, no more bad than
beneficial, no more harmful than harmless.

Wasp Sting: First Aid

If, despite all your precautions, you do get stung by a
wasp or bee, treat the bite immediately. A bee leaves its
stinger and attached venom sac behind. This is not true of
wasps, but sometimes a part of a wasp stinger will break
off and remain. In either case, gently flick the stinger up
and out with your fingernail, a pocket knife blade or
tweezers. If a venom sac is attached, don’t squeeze it.

Wash the area around the sting with soap and water, and
apply ice or a cold towel. Calamine lotion, or a paste made
of water and either baking soda, meat tenderizer or–
if nothing else is available–mud will help soothe the
sting and prevent swelling. An oral antihistamine (Benadryl
is one brand) also can reduce itching. Aspirin or
acetaminophen can ease the pain. Elevate and rest the
affected area for an hour or more.

Normal reactions to an insect sting occur within four hours
and include soreness and itching, localized swelling and a
general redness around the sting. Many people, however, are
mildly to severely allergic to insect venom. Moderate
allergy symptoms include generalized hives, wheezing,
stomach pain, dizziness, nausea and vomiting. Severe
allergic reactions include any of the preceding, plus
difficulty in swallowing, hoarseness or thickened speech,
weakness, confusion–and in extreme cases, shock, drop
in blood pressure, collapse and unconsciousness.

Most deaths from stings are caused by extreme allergic
reactions. But even a moderate allergic reaction is cause
to see a doctor as soon as possible. You may be becoming
more sensitive with each sting, and treatment by an
allergist may be required.

Wasps and You

When you learn the life cycle, habits and likely habitats
of wasps and combine that knowledge with common sense and
reasonable caution, you have a pretty good formula for
safety.

For example, since bald-faced and sandhill
hornets–and sometimes yellow jackets–build
their nests in brush or tall grass, it makes good sense to
stay away from such areas as much as possible during the
summer and early fall. Be especially careful, too, when
clearing overgrowth or working around logs or downed
trees–also likely nesting sites. When you’re mowing
your lawn, keep an eye out for the telltale activity of
yellow jackets flying in and out of an entrance hole.

If you must be in an area that is likely wasp habitat,
avoid wearing bright-colored clothing, and don’t use
strong-scented cosmetics. Both are believed to attract
insects, including wasps. Also, some entomologists claim
that wasps are especially active and aggressive on hot,
humid days. While this may or may not be true, it’s a good
idea to do garden and yard work in the morning or early
evening, when temperatures–and perhaps wasp
tempers–are cooler.

There’s considerable evidence to suggest that paper wasps
that establish nests near humans–say, over a
doorway–become accustomed to the activity and carry
on their lives without attacking. (In fact, according to
some reports, pioneers in the Midwest used to hang
bald-faced hornet nests in their homes as a way to control
houseflies!) Nonetheless, the closer such nests are to your
home, the greater the potential for
trouble–particularly if you have any curious children
in your family. Probably the best time to think about wasp
control around your home is early spring, when queens are
just emerging from hibernation. Weak and relatively
slow-moving at first, these females can sometimes be
discouraged from establishing nests too close for
comfort–say, near a children’s play area. Try
knocking the foundation cells down with a long pole; the
queen may decide to set up housekeeping elsewhere. If she
persists in selecting that site for her nest, you may need
to make the queen your target–use a stick or fly
swatter–before she has a chance to lay eggs and
nurture the larvae. Killing a single queen is a lot easier
and less hazardous than coping with an established colony.
(This may indirectly account for the old English
superstition that if you kill the first wasp you see each
year, you’ll have good luck and win over your enemies.)

Once a nest has been established, your options become
fewer. Knocking the structure down is seldom
effective–more often than not, the wasps will simply
begin anew at the same site and (worse yet) are likely to
behave more aggressively than ever. Old-fashioned sticky
flypaper, still available in most hardware stores,
sometimes proves a fatal attraction to Polistes
workers; just hang the strips from eaves or branches near
the offending comb.

A yellow jacket nest concealed in a wall of your home
presents a somewhat more difficult problem. Chances are
you’ll need to call in a professional exterminator.
Meanwhile, to prevent the problem from recurring, caulk any
cracks around windows and doors–the most likely
points of entry for yellow jackets.

Underground yellow jacket nests can sometimes be wiped out
by placing a clear glass bowl firmly in the ground over the
entrance hole. (Keep in mind that there may be more than
one entrance, in which case you’ll need to cover them all.)
The wasps won’t dig additional exit holes, and in a few
days will starve to death. A somewhat more aggressive
method, but still preferable to using insecticides, is to
pour fuel oil into the entrance hole.

In any event, these and other techniques for exterminating
a nest–including spraying–should be attempted
only at night, when all the wasps are inside the nest and
relatively inactive. All paper wasps are vision fliers, and
cannot navigate in the dark. Your chances of getting all
the insects in a colony are much greater, and the odds of
your getting stung much less, when you do the job at night.

Finally, learn to recognize the warning signals most wasps
give off when they feel you’re too close. A
Polistes wasp on the nest will lift its wings,
raise its front legs and rear up on its back legs. A hornet
or yellow jacket (or, more rarely, a Polistes )
may warn you away from the nest by flying straight at you
fast. Normally, wasps fly in a somewhat slow, meandering
fashion as they forage; if a wasp comes toward you in this
manner, it means no harm and will likely fly past you. If
it gets too close, don’t swat at it: A slow movement or
gentle wave will send it on its way. Running from a wasp is
pretty much futile, since a paper wasp’s normal cruising
speed is about 13 mph, and its pursuit speed is
considerably faster. Likewise, don’t panic if a wasp
accidentally lands on you; it’ll probably leave on its own
momentarily, or you can make a slight shrugging movement to
encourage it into flight.

That’s all easier said than done, of course. Cool
objectivity is fine when you’re looking at a wasp from a
scientific, arm’s-length point of view–but when
you’re looking at a wasp on your arm . . . well
now. Me, I still go into head-to-toe adrenaline overdrive
whenever a wasp or bee buzzes too close. My stomach still
leaps to my throat, my heart still pounds like a punching
bag. Out of sheer, stubborn pride, I usually
–usually–manage to stand my ground. But
mentally I run like a rabbit.

There’s something about man’s fear of wasps that goes
deeper than reason. Maybe it’s just the natural order of
things. Maybe, in addition to all the other roles the wasp
plays in nature, there’s another: to keep us humans
humble.