Photo credit: treknature.com
Thought crickets are unassuming little chirpers? Think again – upon closer inspection, I have come to realise that African Armoured Ground Crickets are the most revolting and weird insects to walk South Africa, Namibia and Botswana’s semi-dry areas.
Like something from a horror movie, the African Armoured Ground Cricket has some strange defense mechanisms in which it protects itself with. This cricket is deemed the warrior of all crickets, with an armoured exoskeleton containing 5 rows of spine that shield the back of its abdomen, as well as spikes on the front of its pronotum.
If this isn’t creepy enough, I have discovered that the African Armoured Ground Cricket, a.k.a. the Gobabis Prawn, Bush Cricket, or as we refer to it in South Africa, a “koringkriek” is not only geared for possible attack, but when attacked, it has a very peculiar way in which it defends itself in…
When their attackers –birds, lizards and spiders – make their move to feast on these crickets, they expel toxic blood (called “haemolymph”) from the gaps in their bodies to avoid being eaten! They also regurgitate recently eaten food. Now, why would these crickets resort to these extreme measures to deter their enemies? Entomologist Bill Bateman of the University of Pretoria and his colleague Trish Fleming of Murdoch University in Western Australia conducted a study to determine what exactly makes these African Armoured Ground Crickets act this way and whether the haemolymph is actually successful in warding off predators.
What is really fascinating to note, is the amount of control these armoured ground crickets have. From the study carried out by Bateman and Fleming, they have discovered that these crickets have the ability to control how they release their haemolymph depending on how they are attacked. If attacked from above they release a well of blood, and this takes place 90% of the time. When attacked from the side, they squirt out blood sideways from behind their legs almost 70% of the time, and then they also try to bite the attacker. Blood can be squirted up to 6cm in distance! Furthermore, the males stridulate (producing noise from rubbing their hind legs together), while the females rely on squirting blood, biting and vomiting as they can’t stridulate.
That said, the toxic blood these African Armoured Ground Crickets release is green and bitter, which repels the attacker immediately. Their vomit also drives back predators. Wow, can you imagine, bleeding and vomiting at will to get rid of enemies? That is quite a show.
Not only to Armoured African Ground Crickets have odd defense mechanisms, but they also are cannibals! These insects horde in search of food, and that when flocked together in such large volumes, these crickets get run over and squashed alongside the road into what is called a ‘pancake’ of crickets. Crickets find the scent of the injured and bleeding appealing, and this turns into quite a cycle – attracting more crickets to the side of the road that get run over and this attract even more crickets. This makes me think of a scene from The Walking Dead where zombies are attracted to the smell of blood… creepy!
Lastly, when I thought things couldn’t get any stranger, I discovered that when male armoured ground crickets choose a mate, they present the female with a sperm pouch and a spermtophylax (a body of food given as a so-called wedding gift) and together combined this is called a “spermatophore”. They then mate and females lay eggs in a random order. Moreover, males prefer to choose virgins over non-virgins because this means that the chance of the offspring being theirs is greater. They are able to distinguish between virgins and non-virgins as virgins are lighter in mass.
Other than pursuing cannibalism in their free time, Armoured African Ground Crickets also plague pearl millet and sorghum crops. To prevent this from happening, farmers dig trenches around their fields containing insecticide. Crickets simply march in and can’t get out. Quite an easy solution I’d say!
These armoured ground crickets are really not what meet the eye. The next time I see an insect, I will not judge it purely on looks. Although in this case, their rock-hard exterior did give somewhat of a clue as to its nature… This is really an insect I’d rather not reckon with – I would gladly watch an Episode of the Walking Dead than face these blood-squirting, vomiting cannibals any day of the week and be sure to receive a good night’s rest!