Termites an Uninvited Guest PDF.pdf

Termites an Uninvited Guest
This course covers identification including,
antennae, mouth parts, thorax, wings, legs
abdomen the makeup of the castes. Why
termites swarm, temperature, humidity and
the time of year.

TERMITES: AN UNINVITED GUEST
Part1.
• Not all of the termites in a colony have eyes.
Subterranean termites live underground-
where there is no light. When they do leave
their underground colonies to forage for food
that is located above ground they travel from
the ground to the house in tubes that they
construct.

• There is no light inside these tubes. The
termites exist inside of the wood in the house
in tunnels that they have carved out with their
mandibles (their jaws), and there is no light
inside these tunnels.

• The worker spends its entire life in the dark (if
you want to apply a scientific name to "living
in the dark" you can call it "cryptobiotic",
which means, literally, hidden living.
• So, why have eyes? If you were to go into a
cavern far enough so that there was total
darkness, and stay in that cavern for the rest
of your life, you would not need eyes either.

• There must be some light for eyes to be able
to function. So, how do the worker termites
make their way around? There are two ways in
which termites are able to navigate, and those
are by their sense of touch and their sense of
"smell".

• First, they feel their way around - with their
antennae - in much the same way a blind
person might navigate with the use of a cane.
The worker termites are blind. So are the
soldier termites who spend most of their time
inside of the colony. The individuals in the
termite colony that do have eyes are the
"reproductives".

• They swarm out of the colony at certain times
of the year and they are attracted to light with
their compound eyes. They cannot see
anything as long as they are confined to the
inside of the colony, but once they emerge
into the light they are attracted to the
brightest spot available.

• That is why when termites swarm from a
subfloor in a bedroom they are attracted to
the window. It was the source of a bright light.
Termite species that may swarm in the
evening, such as Dampwoods or Formosans,
may be attracted to the light on a front porch,
causing tremendous anxiety for the
homeowner, who may wonder whether they
have a problem in their own structure.

• Many times a homeowner will call a termite
control company and complain about termite
infestations in their window sills, because they
see the termites in the window but in
actuality they have swarmed out of the colony
somewhere else in the house and are
attracted to that window which is the
brightest source of light in that room.

• The eyes of the termite reproductive are
compound eyes that cannot see objects
sharply, like we can, but they can readily
detect a difference in light intensity, such as
when a cloud passes overhead and casts a
shadow on their exit tube. That shadow may
indicate danger to them, and the colony
immediately stops giving off swarmers.

• There are some specific structures on the
heads of termites that allow you to determine
accurately which kind of termite you are
dealing with. These are the "fontanelle" and
the "ocelli", which are simple eyespots that
may be located next to the compound eye.
These are found as follows:

Dampwood termites
- have neither ocelli
nor fontanelle
Drywood termites -
have ocelli but not a
fontanelle
Subterranean
termites - have both
ocelli and fontanelle

• So, what are we talking about here? Well, the
fontanelle is simply a little spot located right in
the middle of the top of the head. It oozes out
an irritating fluid when the termite is
threatened, and thus is a defensive
mechanism. The ocelli are simple eyespots
located just to the inside of the compound
eyes, and likely detect some shades of light
and dark.

• Since color and size are not always consistent
characters for identifying the type of termite,
it is worthwhile to have other, specific features
as well.

• A second means of navigation by termites is
by their sense of smell, and the use of
chemical odors called pheromones.

• These chemicals are given off by termites as
they forage for food, and are detected by
other workers who can follow the chemical
trail, just like a bloodhound following the
scent of a human, to the food source and back
to their colony. We will discuss this further in
the next section.

Part 2
The Antennae
• The antennae of termites look like
marshmallows or beads strung on a wire. If
you look at them through a high powered lens
you will see that they are covered with bristles
(or hairs). This type of antenna is called
"moniliform" antennae, and means that all of
the segments look the same - there is one
("mono") shape and size to each of the
segments.

• These antennae are very important to the
termite, because several senses are located in
the antennae. The sense of touch enables the
termite to feel its way around in total
darkness, as it "sees" the surfaces and objects
it encounters. It also enables termites to "talk"
to each other. When they meet face to face in
a dark tunnel they exchange information by
touching their antennae together.

• Their sense of taste also is located in their
antennae, and as they touch something in
their environment they can taste it. Their
sense of smell is located in their antennae,
and it is here that their Pheromones become
important tools for communication.

• After emerging from the colony the male
swarmer, for instance, locates the female
swarmer by following the scent she gives off
when trying to attract a male.

• His antennae zigzag around frantically until he
finds her, and once he has accomplished this
task he glues his nose to her and follows her
everywhere, until she at last finds a location
suitable for her to establish a new colony.

• So, if you snipped the antennae off of a
subterranean termite worker it would not be
able to see, talk, taste, or smell. If you snipped
the antennae off of a male subterranean
termite swarmer he would not be able to
carry on his courtship ritual. Everywhere one
of the tiny little hairs on the antenna attaches
to the cuticle (that outer shell of an
arthropod) it does so at a tiny opening to the
body. At this opening are sensitive nerve cells,
which detect the tastes and odors so
important to the termite.

• We, as pest control professionals, learn as
much as we can about the anatomy and
biology of the pests we deal with, and this is
one area that sets us apart from the untrained
members of the public, and is the reason we
have the advantage in our ability to control
those pests

• We learn to recognize that the termite has
moniliform antennae, while ants have
"geniculate" (elbowed) antennae, with a 90-
degree bend at their middle. This feature
easily separates the two kinds of insects for
our identification purpose.

• Since both ant and termite swarmers will shed
their wings following swarming, and since the
small, black subterranean termite
reproductives may be confused with some of
the small black ants, knowing of specific
differences is vital for proper control.

Part 3
The Mouthparts
• The mouthparts of a termite perform several
important functions. The first one we think of
is chewing down our house. There have been
many studies about how much wood a termite
can "eat" in a day, and it really isn't very much
per termite, but remember that termites
never sleep.

• If a termite has the assignment of enlarging a
chamber in the wood or extending a tunnel,
the work will be done on a 24-hours-per-day
basis. And, when you think of the fact that a
percentage of the 500,000 termites in the
colony have that assignment, added together
it can amount to quite a bit of damage in a
short period of time.

• But termites, strangely, cannot digest the
wood they "eat" (like we would digest a
hamburger). The main ingredient of wood is
cellulose, and termites, like many animals,
cannot digest this tough material.

• To accomplish this feat they have in their gut a
population of one-celled animals called
protozoa, that secrete enzymes that break
cellulose down into starch, and then other
enzymes that break the starch down into
sugars, and that is what the termite can digest
by itself - SUGAR. They absorb the sugar
through the wall of their intestinal tract and
use it for their energy. Without this population
of protozoa in their gut the termites would
soon starve to death.

• The term for a relationship between two
different organisms is "Symbiosis", and there
are several kinds of symbiosis. One is called
"Parasitism", where one side benefits at the
expense of the other - mosquitoes would be a
good example of parasitic symbiosis.

• Another is called "Mutualism", whereby both
sides benefit, and this applies to the termites
and their protozoans. Actually, symbiotic
protozoa have been found in some other kinds
of insects as well, such as some species of
cockroaches, so it apparently works pretty
well.

• When the “baby” termite (first instar nymph)
hatches from its egg its intestines are sterile -
it is not born with a population of protozoa in
its gut.

• It soon acquires its own population, or
inoculants, of protozoa, however, by licking
the bubble of liquid that oozes out the rear
end of the termites that have been in the
colony for a while, a method of feeding called
"proctodeal feeding". Protozoans are present
in this liquid, and the tiny nymphs now have
the means for digesting their own food.

• Our knowledge of this process is an important
factor in the control of Drywood Termites. One
of the primary controls we have for these
termites is fumigation. Fumigation is not
particularly efficient at killing the eggs of the
termites, but offers some excellent benefits
otherwise and is highly effective at killing all
the workers and other members of the colony.
If all the workers are killed, the newly
emerging nymphs will have no way to acquire
their first dose of the protozoans, and they die
quickly as well.

• Another function of the mouthparts of a
termite is the "grooming" of other termites in
the colony. They lick each other's bodies clean
of dirt and mold, and in the process exchange
bodily secretions. Thus, if a termite has
walked through a pesticide dust and has some
on its body, it will be imbibed by other
termites in the grooming process, and of
course will kill those other termites in due
time.

• One account of termite grooming that I read
offered the gruesome tale of just how far this
can go. The researcher observed a termite
worker grooming another worker and saw
what appeared to be overly aggressive
grooming. The termite doing the grooming
actually nicked through the cuticle of his
companion, apparently found the taste to his
liking, and proceeded to consume the entire
termite.

• As technologies improve along with our
increased knowledge of the termite biology
and the functioning of their colony life, we
again take advantage of the termite habits
themselves, in our control programs. In the
process of grooming the workers remove bits
of fungi from each other, fungi which might
otherwise cause illness and death in the
termite.

• A fairly new termite chemical is on the market,
called Premise, which alters this grooming
habit. The workers that have been exposed to
Premise no longer groom each other, and
Nature's own control measures take place,
with many of the termites dying from natural
diseases.

• Another form of feeding provided to 1st instar
nymphs is called "stomodeal feeding", and
refers to workers regurgitating some of their
pre-digested food for the benefit - and
enjoyment - of the new nymphs. The contents
of the alimentary canal of one termite are
deposited into the mouth of another hungry
termite, and it also is referred to as
trophallaxis. In the process sugars are passed
along through the colony as well as any
pesticide that happens to be in the food.

• Another function of the mouthparts of the
termite worker is to lick off the outside of eggs
that the Queen termite has produced, and to
stack them in the cell that has been prepared
for them. The workers transport the eggs just
like a mother cat transports her kittens - by
picking them up in their mouth and placing
them where they belong.

• Remember that a termite colony in the ground
is liable to be a very damp place, very
conducive to the growth of molds and fungi. It
is the job of the termite worker to keep the
eggs in a healthy, semi-dry state.

• Another function of the mouthparts of a
subterranean termite worker is the
construction of the tubes or tunnels that allow
the worker termites to travel from the colony
in the ground, up over a concrete foundation,
and into the wooden structure of the house
without ever emerging from the darkness of
the tunnel.

• These "tubes" are made of soil and liquid
excrement. The process is much like we would
use in building a brick chimney. A mouthful of
soil is placed down and a drop of liquid from
the rear end of a termite is placed on top of it
(just like a bricklayer would place mortar).

• Then, another mouthful of soil is placed on
top of the drop of liquid. This liquid is much
like a fast drying model airplane glue, only
without the side effects, and acts to stick the
soil particles together. The process is repeated
again and again, and behold, a tube is formed.
Termites work together to get this task done,
and it is amazing how substantial a tube can
be built in a very short time.

• The mouthparts of a soldier termite are
modified to form a scissors-like instrument
protruding from the front part of the head,
and designed to cut off the legs or antennae
of an attacker or, in the case of an ant, to cut it
in two. These mouthparts are so specialized
for the defense of the colony that a soldier
termite cannot even use its mouthparts to
feed itself. It has to be fed by workers in the
colony through trophallaxis (which we already
have defined.)

Part 4
The Thorax, Wings and Legs
• So much for the functions of the various parts
of the head of the termite. Now, let's move on
to the thorax, which is located just behind the
head. This is where most of the muscles are
stored that enable an insect to run or fly.
Thus, it is the place where the legs and wings
of an insect are attached.

• In classifying insects into their respective
ORDERS, wing structure often is used. Those
of you who do crossword puzzles will run
across a clue that says "wing" or "wing-like
structure". The puzzle is looking for the Latin
word for wing, which is "ALA" in the singular,
or "ALAE" in the plural. Alar would mean
wing-like, and the winged reproductive caste
of termites are often referred to as the
"Alates".

• However, the ORDERS of insects use the Greek
word for wing, which is "ptera". So, when you
read the name of the order to which a
particular insect belongs you will see "ptera"
in that name. Ptera is combined with other
letters that describe the wing of that insect.

For instance:
• Flies belong to the Order Diptera. "Di" means
two, so all members of the Order Diptera have
two wings.
• Bees and wasps belong to the Order
Hymenoptera. "Hymen" means clear membrane,
so all members of the Order Hymenoptera have
clear, membranous wings.
• Beetles belong to the Order Coleoptera. "Coleo"
means sheath, so all members of the Order
Coleoptera have hard, sheath-like forewings.

For instance:
• Butterflies and moths belong to the Order
Lepidoptera. "Lepid" means scale, so all members
of the Order Lepidoptera have tiny scales on their
wings, which form color patterns distinctive to
each kind.
• Termites belong to the Order Isoptera. "Iso"
means equal, so all members of the Order
Isoptera have four wings of equal length. (This
will differentiate them from bees, wasps, and
ants, which have 4 wings, but the front pair of
wings is longer than the hind wings.)

• It is only the adult male and female termites
(the swarmers) that possess wings. Termites
are not strong fliers, and when they land after
a short flight they use their mouthparts and
front legs to tear their wings off at a pre-
stressed line at the base, leaving only the
short stubs attached to the body.

• They no longer need their wings, and the
wings would just get in the way during
courtship, new colony establishment, and
future movement within their enclosed
galleries. It is the presence of these short wing
stubs that helps us identify the bug we are
dealing with as a termite, and separates it
from some similar looking beetles, called Rove
Beetles, that also have very short wings.

• Termites, being insects, have three pairs of
legs - that is, three legs attached to one side of
the thorax and three legs attached to the
other side. The termite's wings are attached to
the upper side of the thorax, whereas the legs
are attached to the lower side of the thorax.
The muscles that cause the wings and legs to
function are located within the thorax.

Part 5
The Abdomen
• The third major section of an insect, the
abdomen, is located directly behind the
thorax. In the case of a bee, wasp, or ant the
abdomen is joined to the thorax by a thin
"thread-like" structure called the "pedicel", or
commonly referred to as their waist. In the
case of a termite the abdomen is broadly
joined to the thorax, without the thin waist,
and this provides another easy way to
differentiate an ant from a termite.

• The abdomen of a termite has several
important functions. The obvious one, of
course, is its involvement in sexual
intercourse, which guarantees the
continuance of the species. A less obvious
function is the part the abdomen plays in the
building of the mud tubes that extend over
the foundation walls of infested homes.

• In the case of Drywood Termites the contents
of the large intestine are squeezed dry, and
the liquid reabsorbed through the intestine
wall. The Drywood Termites live in wood with
very little moisture content, and they need to
conserve every bit of moisture they possibly
can in order to survive. Thus, the Drywood
Termite squeezes out a hard, dry pellet.

• In the case of the subterranean termites water
is added to the contents of the large intestine,
and the termite squeezes out a slurry which is
fairly fast drying, and is used to cement
together the particles of dirt that are used in
construction of their tubes (tunnels).
Subterranean termite workers, who are
working above ground in a structure, return
regularly to their below-ground colony, not
only to return food material to the colony, but
also to replenish their moisture supply and to
prevent dehydration.

• In the insect world we learn to "never say
never", and odd-ball things show up at times
that seem completely out of character. I once
had a termite operator show me some
"tubing" that he had found in a wooden crate
in his mother's backyard. Termites were
moving through this tubing, but the tubing
was composed of Drywood Termite fecal
pellets all stuck together, and the termites
that were using this convenient pathway were
distinctly Drywood termites.

• Now, these termites are not supposed to
make tubes, but in consulting with one
industry expert on it his reply was "Sure, why
not? If a termite needs to get from Point A to
Point B, and stay hidden in the process, they
will do whatever is necessary to get there."
Formosan Termites carry this to an extreme,
using their body liquids mixed with chewed up
wood to create "carton", an extremely hard
matrix that may fill entire wall voids, and
which is used for their living quarters.

Part 6
Castes
• Now, let's take a look at the different types of
individuals, or "castes", found in a
subterranean termite colony. They fall into
three categories. By far the most numerous
are the "WORKERS" of the colony. As the
name suggests, they do all the grunt work of
the colony.

• By far the most numerous are the "WORKERS" of
the colony. As the name suggests, they do all the
grunt work of the colony. They take care of the
eggs that the queen produces, keeping them
clean and dry and healthy. They feed the little
baby termites that hatch out of the eggs with
material that they regurgitate into their mouths.
These "baby" termites that have just emerged
from the eggs are in what is called the "first
instar" stage.

• They are unable to feed themselves and have
jaws too weak to chew off wood. After a short
while their "exoskeleton" starts to harden like
a suit of armor.

• Human beings have what is called an
"endoskeleton", or in other words a skeleton
on the inside of us. We have head bones, arm
bones, leg bones, and most of us have
backbones. These bones are covered with a
layer of muscle that is covered by a layer of fat
(some of us are blessed with more of this layer
than others are), all of which is covered with a
layer of skin so that, when you look at each
other, you do not see our skeleton at all.

• Insects, on the other hand, have a skeleton on
the outside of their body, made up of a
material called "chitin". This skeleton is a
protective covering, much like a suit of armor,
that is relatively impervious to intrusion by
things from the outside. When an insect
wants to grow bigger it has to lose that suit of
armor somehow, being softer and pliable for a
day or two, expanding, and then forming the
new exoskeleton

• The termite nymph has the ability to split the
suit of armor right down the middle of its
back, and then it steps out and leaves the old
skeleton behind. It now has a new skeleton
one size larger! The process of getting out of
its old skeleton is called molting. The stages
between molts are called "instars". A termite
molts six times, so that it has seven instar
stages, the seventh one being the fully
developed adult, possibly a worker, a soldier,
or a reproductive.

• In subterranean termites there is an adult
stage called the "Worker", while in Drywood
and Dampwood Termites all of the nymphs
ultimately become either Alates or Soldiers.
There is no adult worker caste in these groups,
and all of the workers are simply immature
nymphs.

• When the immature termites reach the third
instar stage they are able to survive on their
own, and are therefore put to work. Some of
them serve to attend the Queen, some of
them nurse the young termites, some of them
feed the soldier termites. Some of them chew
through the wood, extending the excavations
and thus eating away at the wooden structure
of the house.

• Some of them work to build the tubes that
extend up over the foundation walls. All of
them have a job to do. When they reach the
fifth instar stage some of them begin to be
modified into soldiers or reproductives, while
the rest of them stop development and
remain as workers for the rest of their lives.
The average lifespan of a worker termite is
two years. Since the Queen continues to lay
eggs all day and night for fifteen years or
longer, the workers that die are replaced
quickly, and the colony grows in number.

• The second member of the caste is soldier
termites. They have no other function than
the protection of the colony. When the
swarmers are about to fly out of the colony, or
if a breach in the colony occurs, a hole being
produced in the tubing that would allow
enemies in, you can observe the soldiers with
their large mandibles quickly ringing the exit
or opening.

• They stand there in a highly protective stance,
and if an ant were to intrude at that point it
would merely be cut in two by the large,
scissors-like jaws of the soldier.

• The third type of individual found in the
colony is the reproductive, or "swarmer",
sometimes called the "alate" (borrowing from
the Latin word for wing - ALA). These
individuals have gone through six molts of
their exoskeleton and are now full-grown
adults capable of sexual reproduction. Their
function is to exit from the colony, mate, and
establish a new colony separate and
independent of the one that they just left.

• These fully grown, sexually mature adult
termites are produced in the colony year round.
They are a result of the sixth instar termites
molting for the last time. They accumulate in the
colony and are fed by the worker termites. As
the time draws near for them to exit the colony
in masse they crowd around the exit tubes built
by the worker termites.
What causes them finally to exit from the
colony?

There are three major stimuli that cause the
subterranean termites to swarm:
A sudden increase
in the humidity
inside of the exit
tubes
The proper
temperature
outside of the
exit tubes
The proper
light intensity
outside of the
exit tubes

• When you consider that the major swarming
in the springtime is on a nice sunny morning
just after a rain, you can see that such an
environment fulfills the three conditions listed
above. First of all, it has just rained. This may
have been a heavy rain that has lasted several
days or it may have been a light shower. At
any rate, the rain has increased the humidity
inside of the exit tubes.

• This sends a message to the swarmers that
the ground outside probably is soft and easier
to dig into than if it were dry and hard. The
soft dirt increases the chances for success in
excavating a pocket in the soil, and thus
increases the chances for survival of the
species. Somehow, the termite swarmers
know that.

• Second, the proper temperature - around 70
degrees F, plus or minus a few degrees - must
be present. An increase in humidity in the exit
tubes could exist because of a snow storm or
because of a rainstorm followed by a severe
cold snap.

• Termite swarmers will die off from the heat on
a hot, dry day before they can find their way
back down into the ground, or they may
freeze to death rather quickly if the
temperature is too low. In these cases,
swarming will not occur. A nice, gentle
temperature just after a rain is most suitable
to the swarming process.

• Third, the proper light intensity must be
present outside of the swarming tubes. This
light intensity occurs on a warm spring
morning, just after a rain when the clouds
clear away and the sunshine comes beaming
through. When these three conditions mesh it
appears to the termite swarmers inside of the
tube that the time is right for an exit from
their old colony. Remember, that it is only a
small percentage of the termites in the colony
that swarm at any one time.

• The colony continues to live on, the workers
continue to do their assigned tasks, and more
swarmers mature for the following swarming
season. It is best to remember that a colony
does not give off swarmers until the colony is
at least three years old. By that time there are
enough termites in the colony that it can
afford to lose large numbers to the swarming
process.

• So, out they come, flying toward the brightest
light, which usually is the sun. If the colony
was well-established there will be hundreds of
swarmers emerging. Half of these are males
and half of them are females.
• Termites are not strong fliers, and if they were
to fly a hundred yards it would be considered
a strong flight.

• Sometimes a prevailing wind will blow them a
little farther, and usually in the direction of
the wind. When they finally land on the
ground their first action is to break off their
wings. The wings are no longer needed, and
might get in the way in courtship or colony
development.

• The wings have a suture near the base of the
wing, much like the perforated strip across the
top a legal pad. The termite tears off its wings
along this pre-stressed line too, using its
mouthparts and its front legs. The wings are
easily discarded, and now the male is ready to
find a female termite.

• The female is ready too. She lifts the end of
her abdomen up high and emits a perfume (a
sex pheromone) from the tip of it to attract
the male. As you recall, the male uses his
antennae to smell with, and when the male
smells this delicious perfume his antennae
zigzag furiously, and he starts running in
circles, each circle getting smaller until he
finally finds the source of the smell - the
female termite.

• At that point in time the female lowers her
abdomen and the male places an antenna on
each side of the female's abdomen, and they
walk off together, the male following the
female who is looking for a suitable place to
excavate their nuptial chamber.

• This may be under an old board on the
ground, alongside an old tree stump,
alongside a foundation wall, or a hundred
other places where the ground is soft and the
digging is easy. They then work together to
excavate a hole in the ground, by using their
mandibles (jaws) to move a tiny piece of dirt
at a time, until they have created a cavity large
enough for them both to fit in and to move
around.

• Then they close the door to this chamber in
the same way that the worker termites build
tubes - they stick bits of dirt together with
anal secretions until they have formed a nice,
snug little nest once again, hidden away from
the rest of the world and secure from their
enemies.

• It is at this time that the male and female
termites mate. This pair lives together in the
colony for years, with the male inseminating
the female at intervals. Over time the original
Queen develops an extraordinarily expanded
abdomen, as her ovaries expand
tremendously to support the huge volume of
eggs she lays daily.

• Other queens, called "secondary" queens, also
develop, and produce small amounts of eggs
themselves, but the primary queen does the
bulk of it.

• This entire process of swarming, pairing off,
and digging their way back into the earth may
take a few minutes or a couple of hours at the
most. It is during this swarming process that
the termites are exposed to their enemies.
Birds and lizards pick them off, dragonflies and
robber flies dine on them, and ants have a
field day with them.

• It is also the only time that humans usually
see termites. The rest of their lives are spent
in a cryptobiotic existence - hidden away in
the ground or in tunnels in the wooden
structure of your house.

• Photos courtesy of photographers published on
Bugwood.org ITP Node
• USDA Forest Service, Bugwood.Org
• The use of trade names in this publication is
solely for the purpose of providing specific
information. American Pest CEUS does not
guarantee or warranty the products named, and
references to them in this publication do not
signify our approval to the exclusion of other
products of suitable composition. All chemicals
should be used in accordance with directions on
the manufacturer's label. Use pesticides safely.
Read and follow directions on the manufacturer's
label.

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Termites an Uninvited Guest PDF.pdf

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