What’s more frightening? A wasp with with huge forelimbs for grasping prey, or a mantis with a deadly stinger? Mantises are scary because of their huge “raptorial” forearms made for catching prey such as other insects or hummingbirds. They also appear to be staring right at you all the time, looking deep into your psyche and judging you on your most embarrassing Google search histories. However, mantises lack venom and their flying ability is laughable. Wasps are great flyers have terribly painful stings. They are also unpopular jerks, stinging you because you are trying to enjoy your steak out-of-doors or because they built their nest where it would be an excellent target for a thrown rock. Clearly, both insects could benefit if somehow they were crammed together into a single organism combining their strengths and compensating for their physical weaknesses and personality flaws.
Observe! The advanced monster I have described already exists! Introducing the Mantispid®, offering the front-end power and predatorial instincts of the Mantodea, with the streamlined slim-waist, pointy abdomen and “I’m gonna sting you, softy” coloration of the advanced Hymenoptera!
Observe again! that I am lying. Clever breeding nor genetic experimentation have not in reality created a new species of super-insect, not has the above image been created using Photoshop. I captured this creature on a second trip to Maupin, OR to look for Brochymena sp. of stink bugs. Despite their terror-inducing appearance, Mantispids, or mantis flies, are not harmful to humans. Remarkably, they are also not closely related to mantises (Order Mantodea) or to wasps (Order Hymenoptera). The family Mantispidae is part of the Order Neuroptera, of which the most common members are lacewings. Their resemblance to both mantises and wasps is a result of both convergent evolution, or the development of similar character traits by two unrelated groups, as well as Batesian mimicry, where a relatively harmless organism develops an appearance that makes it look like a more harmful organism. While that in itself is compelling, there is far more that makes this insect one to know, and to impress your friends with, as I am impressing you now.
Mantis flies have a complicated and fascinating life cycle. They are holometabolus, which means that they go through a complete metamorphosis (egg, larva, pupa, adult). The larvae are very tiny and are have very long abdomens. They will prop themselves up so that their legs are heads are pointed upwards with their pointed abdomens anchoring them to the ground. Imagine an ice-cream cone standing on its end, with 6 pretzels (the legs) coming out of the ice cream scoop. It’s in this position that they will wait for a spider to pass by. When a spider brushes past them, they will grab on tight and climb onto the spider’s body, positioning themselves into the space where the head/thorax meets the abdomen (the pedicle). It’s here that they will spend most of their larval life.
The primary objective of the Mantispidae larva is to hang out until their spider host lays an egg sac. The nymphs are dependent on spider eggs as their food source. However, spiders only produce eggs as adults. What happens when a young spider is boarded? Besides no eggs, another issue is that the spider, like other arthropods, will molt, shedding it’s exoskeleton (and in the process a young mantispid along with it). The mantispids overcome this problem by relocating to the spider’s book lungs (an internal organ with exterior openings, like gills on a fish) before it molts, and remain there until the molt is complete, where is will return to the spiders outer body. This is repeated until the spider is a mated adult that is able to reproduce and create an egg sac. If necessary, larval mantispids can remain on spider hosts throughout the winter, while the spider is reproductively dormant. What tenacity!
Mantispid larvae can enter the egg sac while it’s being created and get wrapped up within it. Some species do not hitchhike on the spiders, and have a better time locating and entering sacs that have already been constructed. Once inside the egg sac, the mantispid larvae will consume the spider eggs. After all of the eggs are consumed, will then pupate, eventually metamorphosing into the adult you see pictured here. Perhaps spider eggs are delicious and we’ve all been wasting our time on chicken eggs, which thankfully do not require one to spend their childhood upon a chicken. Chickens also conveniently lay eggs in paper cartons instead of cottony sacs like spiders.
Despite their uncanny resemblance to members of the family Vespidae, such as paper wasps, adult mantispids do not sting and are not terribly aggressive. This specimen was the size of a large yellow jacket. The adults are predacious and can move quickly. Their visual acuity is not as developed as their doppelgängers in the family Mantidae, but they are still very capable attackers. According to one study, their capturing behavior for catching and holding insects can be as fast as 60ms, triggered by the prey coming within a certain distance of the predator’s eyes and striking based on triangulation. And those spiky arms! So many spikes to impale some annoying flies.
So, if you dislike spiders, meet your new champion! If you are afraid of insects, meet your new nightmare (I know I said that these are harmless, but you are afraid of insects that are mostly harmless already). A few species can be commonly found across North America, although this is the first one that I’ve caught. It was unexpected and exciting. There are over 400 species of Mantispidae, and occur with the most diversity in tropical areas. For some free, impressively thorough, and fairly accessible scientific reading about a North American species, Mantispa uhleri click on the reference below for Redbord and Macleod.
References: Redbord and Macleod 1984, EOL species, Kral, et al. 2000,
Oregon Beat Sheet 
a very interesting and equally entertaining read!
Does the spider know it has been boarded, or try to shake/brush off the mantispid?
Two thoughts one this; First, the imagery presented in the first paragraph is the stuff nightmares are made of. Second, you definitely need to draw a cartoon of a young child, desperately clinging to the underside of a chicken, for this article.