When thinking of fierce little critters, poisonous spiders often come to mind. Their fear-inducing image is all over right now for the spooky Halloween season. But there’s actually a group of insects that hunts spiders – the aptly-named assassin bugs. And how they accomplish this feat is quite amusing – the assassin bugs will often “trick” a spider into thinking the bug is caught in a web, and then grab and strike at the spider when it gets close. But if a spider is lucky, it may win with a counterattack and eat the assassin bug instead.
These impressive, stealthy predators eat many different types of insects (including bees!) as well as other little critters, like the arachnids. The assassin bugs do this by using bristled, thin front legs to grab their prey, and a beaklike mouthpart to stab it. These vicious predators then inject deadly saliva (with specialized enzymes) into their captured prey to liquefy it. They then proceed to suck out their prey’s liquid insides.
Assassin bugs are a very successful group, being found pretty much all over the world and including thousands of species. However, since they come in a variety of shapes and diet preferences, some are much more welcome in a person’s house than others. For example, the desirable “masked hunter” (Reduvius personatus) lives in houses and keeps pest populations (like bedbugs, termites, or cockroaches) at bay. Like many assassin bugs, it can camouflage itself – some crafty assassin bugs remarkably use other dead insects as camouflage, while the masked hunter uses dust and debris found in a person’s home. On the opposite end of the spectrum, the human blood-suckers known as “kissing bugs” (belonging to the Triatoma genus) are very unwelcome guests since they can transmit a potentially fatal disease (Chagas disease) to people in Central and South America. (They got their name for specifically biting people’s tender skin around their lips and eyes.) And just about every assassin bug has the ability to deliver a painful bite, with their stabbing mouthpart and liquefying saliva, so it’s not recommended to handle them, even if they aren’t carrying a dangerous disease!
So, although they have some undesirable relatives, remember that there are beneficial insects out there, like the masked hunter, who are trying to fight for us to keep our houses free of bedbugs, termites, cockroaches, and other little pests!
For further reading:
- Duncan Geere’s article “Assassin Bug Eats Spiders After Feigning Capture” in WIRED
- Teisha J. Rowland’s book Biology Bytes: Digestible Essays on Animals Both Commonplace and Bizarre
- BugInfo.com’s article “Nature’s Assassins: Assassin Bugs”
- Butterfly Pavilion’s webpage Insects: White Eyed Assassin Bug