Female giant rainforest mantises grow up to strike harder than males

If giant rainforest mantises went to kindergarten, little girl mantises wouldn’t look any bigger and stronger than the little boy mantises. Not until the end of mantis high school would lady mantises become the bigger sex. Then, female hunting strikes become more forceful than those of males.

The first series of measurements of this mantis’s predatory strike force from teensy insects-to-adulthood clarifies when hers and his power strikes diverge, a team from Kiel University in Germany reports in the March Physiological Entomology. The researchers now have a new unanswered question, though. Mantises, especially adult females, wallop the test apparatus harder than predicted based on a key muscle’s size, says Kiel entomologist Thies Büscher. So where’s that extra power coming from?

These Hierodula majuscula mantises, native to Australia, use this force in ambush hunting. Instead of roaming for prey, the insects freeze into statue-stillness. When something inattentive and edible strays into reach, the mantises suddenly reanimate, snapping out specialized raptorial legs in a lightning-quick attack.

That attack is not a killer punch so much as a body snatch, Büscher says. The mantises don’t have venom, but their mouthparts are sharp. (Yes, he’s been bitten. Not fun, but rodent bites hurt more.) What typically kills the snatched prey, he says, is fluid loss as the mantis bites into its still-living meal.

To measure the power of such strikes, researchers tucked a yummy fly larva into a little see-through box fastened onto an instrument measuring the force of attacking mantises. “They are always hungry,” he says.
Hungry little mantises grow up in stages. When their hardened outer covering becomes too tight, they upsize. They typically need six molts for males and seven for females to reach full size, stretching about the length of an adult human hand. Even at that size, though, they rarely weigh more than 3.5 grams, little more than a U.S. penny.

The youngest ones tested, who had only molted twice in their series of little growth spurts, hit the fly box with only roughly 2.5 millinewtons. Adult males, however, whacked the target with roughly 70 millinewtons and adult females with about 196 millinewtons.

Though the mantises’ strike force can increase a lot from infancy to adulthood, other body traits—like weight—change in different scales, leading to some odd effects. “I’m interested in scaling,” Büscher says.

Usually strike force, for instance, grows in proportion to the area of a muscle’s cross-section. That’s just a two-dimensional measurement, but insect bodies grow in three dimensions. Yet 3-D whole-body weight grows faster than the 2-D muscle area. So for their size, some wispy little youngsters pack a (proportionally) stronger punch than the full-size hunters.

Just measuring the particular muscle’s cross-section, however, predicts that giant rainforest mantises shouldn’t be able to hit as hard as they do, Büscher says. Some other animals have evolved ways of storing power, such as building up pressure on a latch-and-spring mechanism until it finally pops open, releasing the accumulated energy. This workaround permits athletic feats such as extreme speed in a mantis shrimp strike or the sudden somersaulting of a gall midge larva. Yet Büscher hasn’t found any hints of such a phenomenon in mantises and now suspects that maybe there’s another muscle or other ignored anatomical part involved in some way. The hunt continues.

We do know that what gets caught gets eaten, says evolutionary physiologist Christopher Oufiero of Towson University in Maryland. He hasn’t measured the force of strikes, but his lab has worked out how fast 14 mantis species eat — based on watching the insects get more than 300 flies through their mouths.

The adult female mantises in his tests, all specialists in some form of camouflage, proved swift eaters not limited by their mouthparts, he and colleagues reported in the February 2026 Ecology and Evolution. Overall, the team concluded that mantises can readily eat more than they need just to survive. They feed less like other insects and more like spiders.