Download Praying Mantises

Praying Mantises
(Tamil: kumpidu poochie)
Don’t be deceived by the pious name or
the appearance of praying, because there’s
nothing pious about the behaviour of these
insects, whatsoever! In fact I sometimes
think they would be more appropriately
named Preying Mantises, as that’s what
their praying posture is really all about.
The Praying Mantis has awed and
intrigued humans from earliest times with its distinctive mannerisms. It was the Greeks who first called it
‘Mantis’, meaning soothsayer, prophet, or diviner. Even today in many parts of the world it is treated with
great awe and respect. Some consider it bad luck to kill or touch one. In parts of Italy they are thought to
bewitch people. In Provence in France, a lost child is said to be able to find its way home from the direction
in which a mantis points its leg. In Morocco, shepherds declare that if they get lost and find a mantis, it will
point with its foreleg to the north. In Turkey and parts of West Asia they claim that it faces Mecca when
it settles into its praying posture. In the Far East it has long been a symbol of bravery and ferocity; there’s
even a Kung‑Fu posture which imitates it. And in ancient China their egg masses were prescribed as a cure
for cramps, warts, gonorrhea, asthma, bladder troubles, hip pains and bed wetting. Some people even keep
them as pets, as they accept handling.
General introduction
The closest insect relatives to mantises/mantids are the termites and cockroaches, from which they are
thought to have descended. Or should one say ascended, as whilst termites are pests and cockroaches are
reviled, mantids are on the whole respected or even revered. Altogether there are around 2,200 species
worldwide, with maybe 200 in India, the vast majority located in tropical or sub‑tropical climates. They
vary considerably in size, from ant-size species to some which are several inches long. Also colours and
form vary according to habitat. Most range from leaf greens to earth or dust browns, but a few are highly
coloured or superbly camouflaged, resembling flowers, twigs, grass, ants, dead leaves, or even bits of lichen
or the bark of trees.
Flight and escape
Although they may have well developed wings – sometimes strikingly coloured – adult mantises
are not strong fliers. The females of most species are in fact flightless. This, plus their often clumsy
attempts at escape, leaves them somewhat vulnerable to fast moving determined predators, though like
squirrels they are good at keeping on the opposite side of tree trunks or branches when the occasion
warrants it.
Mantises as predators
It is as predators that mantises really come into their own. Firstly, they are equipped with excellent
daytime eyesight, supported by an uncanny ability to swivel their head through 180 degrees. Once they spot
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a flying insect, their compound eyes lock on to it frontally, and the whole head swivels to follow its flight,
rather like a gun turret on a ship. Their night vision, however, is poor, though they will often come to a light
and take advantage of it to catch insects.
Sometimes, slowly and stealthily, mantises will stalk their victims. Normally they just lie in wait,
remaining – apart from occasional swaying like a wind‑blown leaf or blade of grass – rock still for long
periods of time, with their two front legs raised in the classical “praying” posture. When they do move to
take prey, it is with such speed and ferocity that the human eye can’t follow. In just a twentieth of a second
their raised front legs lash out and back, impaling the victim on a row of vicious spikes on the inner edges
of the legs. The action is comparable to the serrated blade of a clasp knife suddenly opening and then
immediately snapping shut.
Diet
The prey of mantises generally includes any creatures small enough for them to successfully capture and
devour, such as grasshoppers, crickets, caterpillars, butterflies, moths, spiders, flies, wasps, bees and other
insects, all taken alive. In South America certain large mantises are also known to take small frogs, lizards,
snakes, rodents and birds, such as humming birds (the only birds, incidentally, which can fly backwards!).
Cannibalistic tendencies
In addition to the above, in cannibalistic fashion all
mantises devour other mantises. What’s more, that not
only includes their brothers and sisters from the moment
they are born, and any other mantises later encountered,
including ones their own size, but also extends to the
eating of mates. Like many female spiders, female
mantises often kill their male suitors, eating them alive,
even during the act of copulation. It is one of nature’s
most grisly and fascinating sights. While the female
may be steadily devouring the generally smaller male’s
body from the head downwards over her shoulder, even
with the head and thorax eaten the stump of the male’s
abdomen on its remaining supporting legs may continue
the mating action for hours, thanks to an independently
operative nervous system (How’s that for sexual drive?)
And as if that was not enough, the female will just as
readily eat her own children when they hatch if she
happens to be around! Finally, after eating, they go
through a meticulous ritual clean‑up of their bloodied
forelegs to remove all traces of the victim. At least, the
books describe it as a clean-up, but perhaps all they are
really doing is nibbling off the last tasty fragments, like
someone sucking the remnants off an ice-cream stick?
Photo: Igor Siwanowicz
Courtship behaviour
Although sexual cannibalism is common in captivity, and under some circumstances may also be seen
in the wild, Mantises are highly visual creatures, aware of everything that is happening around them, and
it’s not clear whether or not having human observers watching them affects their behaviour. Research using
video recorders in vacant rooms, for example, found that mantises that were not hungry or being watched
actually displayed elaborate courtship behaviour, the male engaging the female in a courtship dance to shift
her focus from her normal pattern of feeding to mating. Successful males usually leap onto the female’s
back, clasp her thorax and wing bases with their forelegs, then arch their abdomen to deposit and store
sperm in a special chamber near the tip of her abdomen.
So far so good, but it is the act of dismounting that is one of the most dangerous times for males, because
it is at this time that females most frequently cannibalize their mates. Perhaps in awareness of this, many
males remain in the mounted position for an extended period of time, presumably waiting for an opportune
moment to safely dismount and get away from a possibly hungry female. Successful males who succeed
and have avoided being eaten get to mate with other females.
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Egg laying
A well nourished female mantis of certain species may lay up to ten times a year, commencing in each
case two days after mating. They usually lay in a head‑down‑tail‑up posture, leaving a typically-shaped
ootheca (egg case, see right)
similar to those of cockroaches,
covered in a frothy substance
that quickly hardens to insulate
and protect the eggs. In this
manner anything from ten to
several hundred eggs may be
laid after each mating, attached
to tree trunks, plant stems,
rocks or walls, or placed in soil
or grass. The females of some
species remain with the eggs till
they hatch; others abandon them,
whereupon the eggs become
vulnerable to attack from several
species of parasitic wasps.
Metamorphosis
As in related insect groups, mantises go through three stages of metamorphosis, namely egg, nymph
and adult, with the nymph and adult insect physically quite similar. (The nymph is just smaller and has no
wings or functional genitalia, is often coloured differently to the adult, and in the early stages may mimic
ants.) On hatching, baby mantises quickly scatter to avoid each other’s cannibalistic tendencies. They then
take up an independent existence, growing to maturity through 6‑9 moults. Not all make it, of course. Apart
from the risk of being eaten by fellow mantises, they also fall victim as newly emerged infants to ants, then
later to certain reptiles, birds and various small-to-medium size mammals.
Defence
Generally speaking, mantises are protected against
predation simply by virtue of concealment, in that
most species make use of protective body colouring
to blend in with the background. However, various
species have gone even further, and have evolved
to not only blend with the foliage, but to mimic it,
appearing as either living or withered leaves, sticks,
tree bark, blades of grass, flowers, or even stones.
Some species in Africa and Australia are also able to
turn black after a moult following a bush fire in the
region, to blend in with the fire-ravaged landscape.
When concealment fails and they are directly
threatened, the mature insects of many species can put
up a good defence. They stand tall and spread their
spiked forelegs, with their wings fanning out wide to
make them seem larger and more threatening, with
some species having bright colours and patterns on
their hindwings and inner surfaces of their front legs
for this purpose. They can also bite or even strike
at their attackers with their spiked forelegs, and in
the case of small birds sometimes damage the eyes.
As part of the threat display, some species may also
produce a hissing sound by expelling air from their
abdominal spiracles. When flying at night, at least
some of the mantis species are able to detect the
echo-location sounds produced by bats, and when the
Photo: Igor Siwanowicz
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frequency begins to increase rapidly – indicating an approaching bat – will stop flying horizontally and
begin a descending spiral toward the safety of the ground, often preceded by an aerial loop or spin. The only
defence mechanism they apparently lack is chemical defence.
Mantises and humans
From the human point of view mantises play an important role in reducing pest insects. Many farmers
deliberately introduce them by depositing their egg cases among vulnerable crops. The only problem is that
they also kill beneficial insects which might be supportive of agriculture through pollination. On balance,
however, as non‑vegetarians they are very much welcomed.
Sparse distribution, for good reason
Not surprisingly, bearing in mind their ferocity and their readiness to see each other as potential snacks,
they are quite sparsely distributed. It’s even said that you’ll rarely find more than one to a bush. That is, until
mating time, when the males – attracted by a no doubt irresistibly delicious pheromone – go a’courting.
Do they know the risks they take? Perhaps, because they certainly don’t rush in like mad fools. They have
been known to take up to an hour to close the last 30cms/12in. to the female! What happens next must
largely be a matter of luck, and perhaps the state of the lady’s appetite. Many males escape unscathed. But
many don’t.
Thankfully human love affairs are different, and the worst that most men can expect (unless married
to someone like Lorena Bobbit) is to be verbally “chewed-up” by an irate partner as opposed to literally
being eaten alive in course of the mating act. If they weren’t, perhaps more men would opt to become
brahmacharis?!
Additional miscellania
* Regarding their conservation status, only one species (Spanish) is listed as Lower Risk/Near Threatened,
though various species in some parts of the world are under increasing threat from habitat destruction.
* Organic gardeners who avoid pesticides welcome mantises as a form of biological pest control. Tens of
thousands of their egg cases are sold each year in certain garden stores in the West for this purpose.
* In tropical species, the natural lifespan of a mantis in the wild is about 10-12 months, but some species
kept in captivity have lived for 14 months.
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