Chinese Mantis

Tenodera sinensis — the Chinese mantis — is the largest mantis species in North America (10-12 cm body length) and one of the most widely-encountered praying mantises in eastern and central US gardens, parks, and meadows. Native to East Asia (China, Japan, Korea), the species was accidentally introduced to Pennsylvania in 1896 in a shipment of imported nursery stock and has spread across the entire eastern, central, and southern US. The species is extraordinarily generalist as an ambush predator: while small mantises take small flies and other small insects, the adult Chinese mantis is large enough to capture and consume substantially larger prey. Documented prey includes butterflies (especially monarchs and swallowtails), bumble bees, yellowjackets, dragonflies, and (most controversially) small vertebrates. The 2013 Nyffeler et al. paper documented Chinese mantises killing and eating ruby-throated hummingbirds at hummingbird feeders — the mantis waits motionless near the feeder, grabs the hummingbird as she hovers, pierces the hummingbird's neck with the raptorial forelegs, and consumes the brain and breast tissue first. The Chinese mantis is widely sold as 'beneficial garden biocontrol' in egg case (ootheca) form by US garden centers — but conservation entomologists increasingly argue against the sales, given the documented impact on monarch butterflies, hummingbirds, and native mantis species (the Chinese mantis appears to be displacing the native Carolina mantis, Stagmomantis carolina, across overlapping range). Chinese mantis is also the subject of one of the most-cited mating biology dramas: females practice cannibalistic mating in many populations, biting off the male's head during or after copulation. The decapitation actually INCREASES sperm transfer rate (the male's body continues mating reflexively without the inhibitory neural input from the brain), making sexual cannibalism arguably 'beneficial' for both partners' reproductive success — a finding that has reshaped the evolutionary biology of sexual conflict.