I was wondering exactly how dragonflies go about subduing their prey. Do they just grab other bugs in midair and just start eating, or is it more complicated than that? Do they eat while in midflight, or wait until they land to feed?
Same question about the praying mantis-- it seems like they just grab and start chewing. Is there any type of poison involved to immobilize the prey, or is it just brute force? Also-- how big do they get and what is the biggest prey they can handle? (I seem to recall hearing that they can actually subdue and consume small vertebrates, but I am unsure if that is really true.)
Any information about these fascinating insects would be appreciated!
I’m not an entomologist, but I have a fairly strong amateur interest in insects - not that it goes far in the credentials department. So, speaking not from authority but from observation, dragonflies pretty much just chomp insects as they fly. From what I’ve seen, dragonflies don’t really seem to be too concerned about eating the entire prey insect. It seems like they just fly up and take a bite, leaving what’s left to fall to the ground (this was with mosquitoes, so perhaps something bigger might fare differently). Anyway, they are amazingly agile; they don’t have much trouble zipping right up close to their victims.
Mantids are very different. They are mostly ambush hunters, staying veerrrrrryyyy still until another insect comes in range and then pow, they strike! When they do finally attack they are really fast, so the prey doesn’t have much of a chance. They catch the prey with their big, strong “forearm” pincers, usually crushing it somewhat - perhaps like Popeye were he an insect.
Neither dragonflies or mantids use poison in subduing their prey. They’re just physically well adapted to their particular styles of hunting.
The largest mantids reach about 20 cm long (8 inches). Large mantids have been known to kill and eat animals as large as hummingbirds.
I’m not sure if this helps, but I once witnessed a praying mantis kill a large spider (Not that big, but I’d say 3 inches end to end). Actually, it was astounding, the spider never stood a chance, the mantis only took the one hit-and-grab, and the spider never put up a fight it. That being said, the mantis (or, maybe the spider, who knows) secreted some sort of blue mostly transparent liquid from it’s mouth (Or, at least the area around it’s mouth). There wasn’t a whole lot of it, but it got on glass, and that’s how we first noticed it, and on a second look we could see a bubble of it coming from the mouth/spider contact point.
But, on the other hand, I’ve seen them devour whole grasshoppers (well, they didn’t eat them whole, they ate the whole grasshopper) with incredible speed and have never seen it in any other instances… not that I go around watching mantids eat things… often.