Despite
apparent semiotic similarities, the female is, in fact, from a genus
not at all related to its common mating partner, which in no way
prevents it from various futile reproductive attempts.
This
pseudo-positive assortative mating – the preference of one gender to
seek out mates with similar or superior characteristics – has been
likened to the behavior of a unique subspecies of baylisascaris that
frequently attempts to reproduce with more developed species in an
attempt to mimic their successful behaviors. Unlike these fecal
parasites, the female is far more aggressive in its mating behaviors.
So
aggressive, in fact, that few species can survive the attempt. For many
years hypotheses regarding these common coitus fatalities were few and
far between, more than likely because of the high incidents of injury
and death among researchers who put themselves at high risk to study the
sexual activities of this unusually destructive female. Fortunately
recent experimental developments have paved the way for researchers to
safely observe for the first time the actual behavior of the species
from initial excitement phase to the inevitable conclusion of its unique
sexual response cycle.
Again
paralleling positive assortative mating, the female is apparently
attracted to males exhibiting dominant behavior such as ritualistic
combat, excessive fat storage, and territorial aggression. However, the
female is again exceptional in that she normally prefers sexual partners
who only manifest dominant behavior traits. In a well-documented
experiment conducted in 2002, when faced with a choice between an
extremely healthy male specimen of a similar species with only a
miniscule colorization differentiation versus a male with obvious
physiological deficits who was only apparently suitable for
reproduction, the female consistently preferred to attempt to mate with
the similarly colored male. It is interesting to note, however, that
this behavior is only common if the female is out in the open. When
isolated, the female will reverse this behavior and become extremely
sexually aggressive toward the colored male.
Once
the female has become attracted to a potential mate, it begins the
courtship by displaying a series of provocative displays apparently
evolved to stun the male to the point where sexual activity is optimal –
for the female, because, as noted, the mating activity of the female in
no way could be considered beneficial to the male. One of the early
displays involves the unfolding of the lower limbs, extending them from
the female’s protective sheath of fibers. These fibers, it should be
noted, have been acquired from the desiccated remains of other,
previous, matings. Extended outward, the limbs thus act mysteriously.
Although they clearly lack any form of healthy musculature or show any
signs that the female could act in any way as a successful brood mother,
most males are lured at least as long as necessary for the female to
continue to the next phase of her sexual courtship. Various research
suggests that there are other, as yet unknown, factors at work at this
stage in the female’s mating behavior. Semiochemicals have been
discussed, as has the concept that the female’s coloring and behavior
somehow mirrors the male’s, even though the actions of this false female
in no way reflect true actions of a sexually mature female of any
species, let alone the male's genotype. One radical theory, as yet
untested, even hypothesizes that the female relies on a form of "bribe,"
consisting of preferred nutrients or items that might make its lair
more comfortable.
Now
close enough to a potential suitor, the female extends a set of hooked
upper limbs evolved to lock around the mate’s thorax, effectively
trapping it. Although this maneuver is largely successful in trapping
the male, it should be noted that some males have been sighted who, at
the onset of this initially aggressive female mating behavior, have
resorted to severing their own limbs to escape. These limbless males can
often be seen at the periphery of the female’s territory, too entranced
by the female’s chemical lure to escape but having become too cautious
to proceed closer and risk her predation.
For
those unfortunate enough not to escape, the female begins the next
stage of her pseudo-mating behavior: the opening of the anterior
mandibles, whereby a piercing stylet extends down and outward well below
even the laryngeal prominence. Evolved with barbs to resist removal,
the stylet is capable of easily puncturing the epicuticle and even
cracking through the most hardened of procuticle. Depending on the
chosen mate, the stylet will enter the head near or even directly
through the vulnerable ocelli or directly into the core of the thorax.
Once
this penetration has been achieved, the female injects neurotoxins that
act as a sexual catalyst for her aggressive mating behavior by markedly
increasing the males susceptibility to pain. Similar in toxicity to
scorpion venom, the wild thrashing of the impaled male further
stimulates the female causing a dramatic increase in the thrusting of
the style. So violent is this activity that occasionally the barb has
been observed penetrating completely through a potential mate’s head,
though this in no way decreases the female’s aggression.
The
next phase of this pseudo-sexual mating begins with the flooding of the
male’s head or thorax with a mixture of enzymes that immediately begin
to break down all present macromolecules. Normally preceding digestion,
this activity does not continue with the removal of the broken-down
tissues. Instead the region liquefied acts as a nutritious "nest" for
the next stage.
In
an action so far too fast to be completely viewed or documented, the
stylet is removed and the hole previously punched through the body of
the male is roughly widened by the introduction of an ovipositor.
Reaching precisely to the previously mentioned digested region, the
female then proceeds to go through a gesture of egg-laying, including
the positing of a large sterile egg into the body cavity of the
still-thrashing male.
This
activity is important to note as it adds a new complexity to this
puzzling behavior. For not only is the female attracted to, and very
often attempts to mate with, members of other species, resulting in the
death of the chosen mate, but the attempt is fruitless as the female has
yet to be observed procreating in any way. Being a clearly unsuccessful
evolutionary development, having no observable biological function
aside from preying on males of other species, how the female still
manages to carry on its genes is a matter of much curiosity.
The mystery of the female's behavior concludes with the last act of its unusual pseudo-sexual mating ritual. While the order mantodea has long been accused of the same behavior, recent studies have indicated that it is not natural in the wild. In the case of this singular specimen, however,
the action has been observed – where it is safe to do so – and
thoroughly documented far too often. Whether it is a way of further
stimulating its own sexual responses or just as a way of procuring
additional nutrients, the eating of the male’s head after sex continues
to perplex researchers and remains a fertile area for further study.
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