No African safari is complete without seeing rhinos, giraffes or lions. If you’re lucky, you might even spot a leopard. All four are big, high-profile animals, worthy of anyone’s bucket list. But beneath our feet (or possibly crawling over them) are minibeasts that share the same name as the megafauna mentioned above – the leopard slug, antlion, rhinoceros beetle and giraffe weevil. And although they may not have the same charm as their namesake, their behaviour is, if anything, even more intriguing.
The rhinoceros beetles are named because of the characteristic horns that the males of most species possess. The largest and arguably most impressive of them all is the aptly-named Hercules beetle. For its size, it is one of the strongest animals on the planet, able to lift 850 times its own body weight. The horns of the Hercules beetle are used by the males to fight one another (the females lack them entirely); one curves out from the head and another up from the insect’s thorax, forming something that looks a bit like a crab’s claw (see image below).
Despite their dramatic (and somewhat daunting) appearance, rhinoceros beetles are almost completely harmless because they cannot bite. This has led the Japanese rhinoceros beetle in particular becoming a popular pet in Japan, and it even sold in vending machines! Only in Japan…
Many children buy or catch these insects and breed them – a male and female together will set you back eight hundred yen or so, which is about eight dollars or six British pounds. The beetles have also become a popular subject in gambling, with two different males placed on a log and people betting on which one will push the other off first.
Madagascar is home to quite a few oddities – large nocturnal lemurs with disproportionately long fingers; frogs the size and colour of tomatoes; and ants that drink the blood of their own young – but few are as weird-looking at this insect: the giraffe weevil. The reason for its naming is instantly obvious: the male has a very long neck, complete with a hinge in the middle. The neck, together with the head, makes up 70% of the insect’s overall body length.
And what do they do with these elongated necks? They nod, of course. The males compete with one another, trying to out-nod their opponents in ritualised fights until one retreats. And so it is that the males with the longest necks (better for nodding, you see) are selected by females. The female has a more modestly-sized neck and she uses hers for construction. She rolls up leaves to create a tube shape and lays eggs inside each one. She will even create small notches on the leaves to create a strip to ensure that it sticks together. In essence, she invented Velcro long before we did.
If ever a slug could be called romantic, this would be the one. Its mating behaviour consists of mucus, more mucus, a bit of bungee jumping and some entwined genitals – probably all highly erotic if you happen to be a slug.
When a leopard slug wishes to mate, it leaves behind a particular scent within its slime trail to advertise this fact and it isn’t long before another slug, having detected this trail with a short pair of tentacles, is chasing after the original. Both, it should be noted, are hermaphrodites, possessing both male and female parts. The chaser, to let the slug in front know that it is right behind and also in the mood for a bit of mating, gives the pursued a small nibble on the end of its slimy foot.
The leading slug then heads upwards to the underside of a branch, and the second one follows it. The two start circling one another more and more until they embrace, and then they release their hold on the branch, sliding downwards on a thick rope of mucus. Now, dangling in midair like bungee jumpers, each slug averts their male organ from just behind their head and they, too, start to entwine. Suddenly, both penises flare out like umbrellas and now, at last, after this long bout of strange slug foreplay, sperm passes from one slug to another and both are fertilised.
And yes, in case you were wondering, those strange blue-ish organs in the image above are the slugs’ penises, each coiled around the other.
The antlion is a Jekyll-and-Hyde creature. As an adult, it is a graceful winged member of the lacewing family that feeds mainly on pollen and nectar, but as a larva it is grotesque and vicious monster. You don’t believe me? Just look at the picture below.
Fortunately, if you happen to be an ant (the antlion’s favourite food), you needn’t have nightmares about these horrible insects chasing after you… because it doesn’t do any chasing. The bad news is that it is an ambush predator, so if you fell into its trap, you’d be dead before you knew it.
The antlion makes a conical pit in the sand by walking backwards in ever-decreasing circles until the larva is barely visible at the very bottom. An ant, scurrying back to its nest, is unlikely to see the inconspicuous pit until it is too late. It tumbles down the side, unable to climb back up to the lip of the cone due to falling sand. As soon as the antlion larva detects the ant’s struggles, it emerges from its lair at the bottom and flicks its head to hurl more sand at the ant, creating tiny landslides in the pit that brings the ant ever closer to its huge mouthparts.
Like a spider, the antlion does not have a distinct mouth so it must first liquidise its prey using powerful enzymes before sucking up the delicious bug juice through a channel formed by the snug fit of the mouthparts. Such a liquid diet is useful because there is minimal waste… and that’s just as well because the antlion larva has no anus. All metabolic waste is stored within the larva until it makes the transformation into an adult, upon which it can finally be excreted. If only human babies could wait that long…