A Millipede Murder
The other day, well it feels like it was just the other day, but more accurately, was probably a few months ago, I was out for a walk on the wildlife estate I was then living on, when I came across this murder scene; the one in the video. I call it a murder scene, as upon investigation, which involved asking good friends who happen to be phenomenal guides, I discovered that this millipede was very likely killed by these same bugs who were at the time busy feeding on it. And, that they are aptly named Millipede Assassin bugs. This begged further investigation, which turned out to be very interesting indeed.
Millipede assassin bugs, which go by the scientific name of Ectrichodia crux, are a subspecies of assassin bugs (Reduviidae), and are known for specializing on millipedes as prey. They are fairly large, as bugs go, with adults measuring up to 22 mm in length, have a stout build, and are shiny black with a distinctive black cross incised on their pale yellow thorax.
Turns out that there aren’t two different bugs in the photograph either, as I incorrectly surmised, as the bright red rounder things are nymphs of the same said bug. Generally, when one finds insects, and other animals, displaying bright colours such as this, they are advertising that they contain poison and are to be avoided by other predators. At the very least, that they taste bad. This is known as aposematic colouration.
Now, millipedes have their own powerful chemical defences that they deploy when threatened in order to protect themselves from predation. But this bad bug (and right now I have the song “Bad bug, bad bug, what you gonna do?” going around in my head) has the means to get past this. It must be said that not much is known about how exactly the millipede assassin bugs gets around these defences, but somehow they do. They ambush their prey, quickly piercing the body, presumably in between the harder outer segments of the millipede’s exoskeleton, and inject saliva containing paralytic toxins and cytolytic enzymes. This very quickly subdues the prey and initiates digestion of the body contents, which are then sucked out by the feeding assassin bugs.
It would appear then that the millipede assassin bug has developed a unique specialisation in a niche market.
There’s more! Apparently assassin bugs are also excellent garden residents, and it's not recommended to remove them from one’s garden ecosystem as they can do wonders for one’s pest control regime, preying upon ants, spiders and caterpillars, amongst others. Although I’m not sure why spiders were included in the list of critters one would want to get rid of?
References:
Beetles in the Bush
Candide
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