World's Biggest Bugs
Hercules beetle (Dynastes hercules) can be 6 1/2
inches long, but much of that is just his horn. (Novita
Estiti licensed under the Creative Commons Attribution 2.0
Before we talk about what the world's biggest bugs
are, we should define exactly what we mean by the word "Bug."
After all, it isn't really a scientific designation. Though often
when we use the term "bugs" we mean insects, some dictionaries
extend that definition to apply to any creepy crawly, critter.
For our purposes we are going to define "bugs" as insects,
arachnids and centipedes.
These creatures are all examples of arthropods:
invertebrate animals that have an exoskeleton (external skeleton),
a segmented body, and appendages with joints. In addition to the
animals noted above, other creatures that would fall into the
category of arthropods would be crabs, lobsters and barnacles.
About 80% of all known animal species are arthropods.
Titan beetle (Titanus giganteus)with its wings spread.
(By Rémih licensed under the Creative
Commons Attribution-Share Alike 3.0 Unported license)
Insects are the largest class of anthropods with
over a million known species and probably a lot of other ones
not yet discovered. Most of the heaviest and largest of the insect
species fall into the order of beetles. Beetles are different
from other winged insects because they have a front pair of wings
that are hard and thick. This front pair of wings act as a protective
cover for the back pair of wings which are fragile and folded
underneath. A ladybug is a common example of a beetle.
There are several different species of beetle that
vie for the honor of being the largest. The Goliath beetle (found
in the rainforests of Africa) have been known to grow up to 4½
inches in length (11.5 cm) and weigh 3.8 oz (100g) in their larval
stage. Goliath beetles primarily feed on tree sap and fruit. Like
all beetles, Goliaths start as eggs laid by their mother which
hatch into larva. The larva, after feeding and growing, eventually
form a pupa. Inside this protective covering the beetle grows,
changes and eventually emerges in its adult form.
Another huge beetle is the Hercules beetle (Dynastes
hercules) which lives in the rainforests of Central America,
South America, and the Lesser Antilles They have been known to
grow up to 6 ½ inches in length (17cm) but most of their length
can be attributed to an enormous horn the male carries. Because
of this, the Hercules is actually much lighter that the Goliath.
A third beetle that is considered amoung the biggest is the Titan
beetle (Titanus giganteus) which is native to South American
tropics. At 4½ inches, its length is very similar to that of the
Goliath beetle lives in the rainforests of Africa and can
be 4 ½ inches in length.(By H. Zell licensed
under the Creative Commons Attribution-Share Alike 3.0 Unported
While beetles seem to have won the contest for the
heaviest insects, they aren't the longest by far. Stick insects
are an order of insects that camouflage themselves using cylindrical
stick-like bodies or flattened, leaflike shapes. One species,
Phobaeticus chani or Chan's megastick, can have a body length
of 14.1 inches (35.7cm). With their legs extended, a megastick
can measure a whopping 22.3 inches (56.7cm) in length. Little
is known about this strange species as it was only discovered
in 2008. So far only a handful have been found. These ultra-long
insects are native to the island of Borneo in Asia, though smaller
species of walking sticks can be found around the world.
is sometimes known as the "snake's head moth" because of
the unusual pattern on its wings. (By
Quartl licensed under the Creative Commons Attribution-Share
Alike 3.0 Unported license)
While they are lightweights compared to beetles
and even Chan's megastick, butterflies and moths can grow to some
impressive sizes if you consider their wingspans. Atlas moths
(Attacus atlas), which are found in the forests of Southeast
Asia and the Malay archipelago, can have wingspans 10 inches across
(25cm). There are two stories about how the Atlas got its name.
First is that the name comes from the giant Atlas, a titan of
Greek mythology. The second is that the color pattern on their
wings looks like a map or atlas. In Cantonese (a form of Chinese
spoken in Southern China) the name means "snake's head moth",
which refers to the odd shape and color pattern of the forewing,
which looks like a snake's head.
Alexandra's Birdwing. (By Mark Pellegrini
licensed under the Creative Commons Attribution-Share Alike
2.5 Generic license)
The largest butterfly in the world is the Queen
Alexandra's Birdwing which lives in the forests of Oro Province
in eastern Papua New Guinea. It has a wingspan of up to 12.2 inches
(31cm) and a body length of 3.2 inches (8cm). Like the Atlas moth,
the female of the species is larger and heavier than the male.
The Queen Alexandra's Birdwing is considered an endangered species
because it has such a small natural habitat -only about 39 square
Most people consider spiders scary even if they
are only a fraction of an inch across. However, spiders that are
really dangerous to humans are rare (in North America there are
only two species, the brown recluse and the black widow). Spiders
do not feed on human blood and only bite people when they feel
threatened. With only one known exception, spiders are carnivorous,
but what they like to eat are mostly unwanted insects. They particularly
like mosquitoes which is one reason to be kind to a spider next
time you see one.
Giant Huntsman holds the record for the largest leg span
at 12 inches. (By Petra & Wilfried licensed
under the Creative Commons Attribution 2.0 Generic license)
The largest spider in the world is the Giant Huntsman
spider (Heteropoda maxima). This spider has a leg span
of 12 inches (30cm) and a body length of 1.8 inches (4.6cm). It
lives in Laos in Southeast Asia. Because of its coloration, a
pale yellowish-brown, scientists think that it lives near the
entrances of caves.
The Giant Huntsman spider was only discovered in
2001. Before that the record holder was the Goliath Birdeater
(Theraphosa blondi) of rain forests in northern South America.
It can have a leg span of almost 12 inches and weigh an enormous
6.0 ounces (170g) which makes it the heavier of the two species.
The Goliath is a member of the tarantula family of spiders and
despite its name, eats mostly insects and other invertebrates.
Occasionally, however, they have been known to dine on frogs,
lizards, bats, and even venomous snakes. The Goliath is the largest
of the 900 species of tarantula spiders that live in almost every
part of the world except Antarctica. Though tarantulas have a
venomous bite, it is rarely fatal to humans.
Though not as big as these spiders, another large
and interesting arachnid is the Heterometrus swammerdami,
a scorpion in India that grows up to 11 ½ inches in length (29.2cm)
and can weigh 2.1 ounces (60g). Fortunately, this type of scorpion
isn't very venomous. In fact it actually kills its prey by crushing
it with its pincers rather than stinging it.
Goliath Birdeater (Theraphosa blondi) has just a
slightly smaller legspan than the Huntsman, but weighs more
at up to 2.1 ounces. (John Snakecollector
licensed under the Creative Commons Attribution 2.0 Generic
The last group on our list is centipedes. The name
comes from the Latin prefix centi which means "hundred", and pes,
which means "foot". The actual number of legs a centipede has,
however, varies with the species. Some have as few as twenty,
others up to around three hundred. There are estimated to be around
8,000 different species of centipedes in the world. They prefer
to live in moist environments as they easily lose water through
The species which is the largest is Scolopendra
gigantea, the Peruvian giant yellow-leg centipede (also known
as the Amazonian giant centipede). It's native to northern South
America and can grow up to 12 inches (30cm) in length with either
21 or 23 pairs of legs. (For some unknown reason all centipedes
always have an odd number of pairs of legs, never an even number).
These creatures are carnivorous, very aggressive and will feed
on almost everything they encounter including insects, tarantulas
and also vertebrates like lizards, frogs, snakes, birds, mice,
and bats. Like all centipedes, it can inject its victim with venom
using pincer-like appendages which are actually a pair of modified
legs. Fortunately, while the sting will give most people severe
pain, fever, swelling and chills, it usually isn't fatal unless
the victim happens to be allergic.
or the "Peruvian giant yellow-leg" can grow as
long as 12 inches and has venomous fangs. (By
Tod Baker licensed under the Creative Commons Attribution-Share
Alike 2.0 Generic license)
While most of the creatures above are impressive,
they pale in comparison to their pre-historic counterparts. Meganeuropsis
permiana, the biggest known insect that ever lived, was a
dragon fly that thrived during the Permian period from 290 million
to 248 million years ago. It had a wingspan of 28 inches (71cm)
and a body of almost 17 inches (43cm). Pulmonoscorpius kirktonensis
was a scorpion that lived in Scotland about 340 million years
ago and was 28 inches long (70cm). Another ocean-going version
of scorpion, Brontoscorpio anglicus, wsa found fossilized
in sandstone from Trimpley, Worcestershire, England and was a
whopping 3.3 feet (1m) in length. Finally, there was Euphoberia
which an extinct form of either millipede, or centipede (scientists
can't decide which) that lived in Europe and North America. In
either case, you wouldn't want to meet one if it were alive today.
It was over three feet in length (1m).
Why were some bugs bigger back in the old days?
Insects don't have lungs but get the oxygen they need from the
air to their cells through a set of hollow tubes (referred to
as "tracheal tubes"). These need to get proportionally bigger
as the insect does in order for the insect to get the oxygen it
needs. The theory is that at some point the tubes get so large
that they no longer efficiently move oxygen and limit the size
of the insect. In prehistoric times, however, oxygen levels in
the air, which are about 21 percent today, were as high as 31
percent, allowing the insects to grow larger even though they
had the same sized tubes. Scientists have found that some modern
insects (particularly dragonflies) grow larger when reared in
artificial environments with high levels of oxygen.
The evolution of birds may also account for smaller
insects. Once birds that ate insects arrived on the scene around
150 million years ago, flying insects had to become faster and
more maneuverable, which usually means being smaller, to avoid
becoming an avian lunch.
insect is Chan's megastick which can have a body length
of 14.1 inches and a total length of more than 22 inches.
(By P.E. Bragg and licensed under the
Creative Commons Attribution-Share Alike 3.0 Unported
A Partial Bibliography
Jesús Molinari, Eliécer E. Gutiérrez, Antonio A. de Ascenção,
Jafet M. Nassar, Alexis Arends & Robert J. Márquez Predation
by giant centipedes, Scolopendra gigantea, on three species of
bats in a Venezuelan cave, Caribbean Journal of Science 4
Why Were Prehistoric Insects Huge? Science Daily www.sciencedaily.com
World's Longest Insect Revealed, Natural History Museum
www.nhm.ac.uk October 16, 2008.
Erik N. Kjellesvig-Waering Brontoscorpio anglicus: A Gigantic
Lower Paleozoic Scorpion from Central England, Journal of