The biggest praying mantises are long, thin species from the tropics of Africa and Southeast Asia, some of them longer than a pencil. “Largest” has two answers, though: the longest mantises are slender twig mimics, while the heaviest is a shorter, stockier African species. In nearly every large species, the record-holders are females, which grow much bigger than males.
The Longest Praying Mantis Species
Guinness World Records lists Toxodera denticulata, found on the Indonesian island of Java, as the largest described mantis species.1A-Z Animals. Discover the Largest Praying Mantis in the World It reaches a body length of about 7.8 inches, roughly 20 cm.2A-Z Animals. Discover the Largest Praying Mantis in the World It belongs to a family of stick mantises, meaning mantises that mimic sticks, so its great length is mostly a very thin, drawn-out body. A close relative, Toxodera maxima, is reported to reach about 7.08 inches, around 18 cm.3A-Z Animals. Discover the Largest Praying Mantis in the World
Stick-like mantises survive by looking like a dead twig, and their slim legs, often held stiffly along the body, break up the outline of an insect. Many sway gently as if moved by a breeze.
Africa’s giant African stick mantis rivals Toxodera denticulata. It is medium brown and commonly reaches up to about 6 inches, around 15 cm.4A-Z Animals. Discover the Largest Praying Mantis in the World The longest specimen on record is an adult female collected in Kankiya, northern Nigeria, measuring 17.2 cm, close to 7 inches.5Karl Shuker’s Blog. DID I SEE AN UNDISCOVERED SPECIES OF GIANT PRAYING MANTIS IN SOUTH AFRICA? It is preserved at the Natural History Museum in London.6Karl Shuker’s Blog. DID I SEE AN UNDISCOVERED SPECIES OF GIANT PRAYING MANTIS IN SOUTH AFRICA? So a typical giant stick mantis is a little shorter than the Guinness species, but exceptional individuals come close.
The word “described” matters here. Records only count species that scientists have formally named and measured, and tropical forests probably still hold unnamed mantises, so an even longer one could turn up.
Official lengths run from the head to the tip of the abdomen. Antennae and outstretched legs are left out, even though they make the insect look larger. The lengths quoted for a species are often upper limits for females, not averages.
The Heaviest Praying Mantis
The West African mega mantis, Plistospilota guineensis, is thought to be the heaviest mantis in the world.7A-Z Animals. Discover the Largest Praying Mantis in the World It lives in West and Central Africa, including Cameroon, Ivory Coast, Guinea, Liberia and Ghana.8ShukerNature. DID I SEE AN UNDISCOVERED SPECIES OF GIANT PRAYING MANTIS IN SOUTH AFRICA? Adult females grow to about 11 cm, roughly 4 to 4.7 inches.9ShukerNature. DID I SEE AN UNDISCOVERED SPECIES OF GIANT PRAYING MANTIS IN SOUTH AFRICA?10A-Z Animals. Discover the Largest Praying Mantis in the World That is much shorter than the stick mantises, but they are bulkier and heavier than giant stick mantises, weighing up to about 10 grams.11ShukerNature. DID I SEE AN UNDISCOVERED SPECIES OF GIANT PRAYING MANTIS IN SOUTH AFRICA?
Most garden mantises weigh only a gram or two. The wording is cautious (“thought to be”) because no official record weights have yet been published.12A-Z Animals. Discover the Largest Praying Mantis in the World
Length and weight records go to different species because the two grow differently. Stick mimics gain length by stretching thin, which adds little weight. A stocky body packs more muscle and mass into a shorter frame.
The mega mantis has a broad, heavy-looking abdomen and thick legs. It is a plain beige or brown, which helps it blend into bark and dry leaf litter rather than mimic a twig.13A-Z Animals. Discover the Largest Praying Mantis in the World
Why Female Mantises Are the Giants
Most mantis species show the common pattern of females being larger than males.14PubMed. Different paths to sexual size dimorphism in two praying mantids, Pseudomantis albofimbriata and Hierodula majuscula Males and females can need a different number of skin sheddings to reach adulthood, so they grow for different lengths of time.15PubMed. Different paths to sexual size dimorphism in two praying mantids, Pseudomantis albofimbriata and Hierodula majuscula Each time a mantis sheds its skin it can get larger, so a female that goes through one more stage than a male can end up noticeably bigger.
Sometimes the gap is large. In one group of orchid mantises, females grew about 1.5 times larger and males reached about 0.87 times the size of those in related groups.16PubMed Central. Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises The size gap there came mainly from females getting bigger, not males shrinking.17PubMed Central. Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises Bigger females are better at catching prey, which favoured their larger size.18PubMed Central. Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises
If you spot a huge mantis, it is most likely an adult female, and size records like the Nigerian specimen are typically females. Males are slimmer, with longer wings relative to the body and longer antennae. Size alone is not proof. The standard method is counting the segments on the underside of the abdomen: males typically show more visible segments than females.
How Big Garden Mantises Get
A young mantis grows by molting, which means shedding its skin; one common Asian species goes through 7 stages before adulthood.19PubMed Central. Antennal Development in the Praying Mantis (Tenodera aridifolia) Highlights Multitudinous Processes in Hemimetabolous Insect Species Young mantises that eat well become adults sooner and end up larger.20PubMed Central. You Are What You Eat: Food Limitation Affects Reproductive Fitness in a Sexually Cannibalistic Praying Mantid
Common garden mantises are far smaller than the record holders. The Chinese mantis is usually the largest garden mantis in North America, commonly around 3 to 4 inches. The European mantis is smaller, usually around 2 to 3 inches. Both are non-native in North America and are often released for pest control.
Sightings often seem larger than they are. People tend to overestimate an insect’s length when judging from a distance.21Mantid Forum. Friend thought he saw a huge chinese mantis They often include the legs and antennae, and rarely handle the insect to measure it.22Mantid Forum. Friend thought he saw a huge chinese mantis23Mantid Forum. Friend thought he saw a huge chinese mantis
To measure a mantis you find, photograph it beside a ruler or coin rather than guessing. Measure from the front of the head to the end of the abdomen, leaving legs and antennae out, to compare fairly with records.
Giant African stick mantises are sold to hobbyists and can reach about 6 inches as adults.24PanTerra Pets. Giant African Stick Mantis Caresheet (Heterochaeta sp.) | PanTerra Pets Shedding the skin is their riskiest time: they hang upside down to molt and need room to stretch out fully, so they need tall enclosures. Check local rules, since some countries restrict non-native insects.
Can Large Mantises Catch Birds
Among insects and spiders that prey on animals with backbones, mantises are the main predators of birds.25Global Ecology and Biogeography. Arthropods as vertebrate predators: A review of global patterns Mantises catching small birds has been recorded on every continent except Antarctica.26The Wilson Journal of Ornithology. Bird Predation By Praying Mantises: A Global Perspective More than 70% of reports come from the USA, often hummingbirds at feeders or flowers.27The Wilson Journal of Ornithology. Bird Predation By Praying Mantises: A Global Perspective The ruby-throated hummingbird is the bird most often caught.28The Wilson Journal of Ornithology. Bird Predation By Praying Mantises: A Global Perspective About 78% of caught birds were killed and eaten, and 18% survived only because a person freed them.29The Wilson Journal of Ornithology. Bird Predation By Praying Mantises: A Global Perspective
If a mantis has caught a hummingbird, gently lift the mantis away using a stick or gloved hand. Check the bird; many freed birds fly off unharmed. Then move the mantis well away from the feeder.
Big mantises eat almost anything, including helpful insects. Garden-type mantises eat insects of every role, with over 75% of their diet being plant-eaters, other predators and pollinators.30Food Webs. Diets of two non-native praying mantids (Tenodera sinensis and Mantis religiosa) show consumption of arthropods across all ecological roles They frequently eat other mantises.31Food Webs. Diets of two non-native praying mantids (Tenodera sinensis and Mantis religiosa) show consumption of arthropods across all ecological roles The large Chinese mantis did eat more invasive spotted lanternflies than smaller species, and adults were better hunters than young ones.32PubMed. Predation efficiency of praying mantises as important natural enemies of spotted lanternfly, Lycorma delicatula Still, be cautious about releasing large, non-native mantises in gardens for pest control.33The Wilson Journal of Ornithology. Bird Predation By Praying Mantises: A Global Perspective
People have little to fear. Mantises have no venom or sting. A large one may pinch with its front legs, which can sting briefly but is harmless.
Why Mantises Don’t Grow Even Bigger
Insects breathe through a network of dead-end tubes that deliver air directly to their tissues.34Argonne National Laboratory. What Keeps Bugs from Being Bigger? Air enters through small openings along the body and travels through branching tubes straight to the tissues, without blood carrying oxygen. Gas moves through these tubes largely by simple spreading, which gets slower as the path gets longer. Because this works less well over longer distances, scientists long thought it kept insects small.35Argonne National Laboratory. What Keeps Bugs from Being Bigger?
The idea had support. Most insects grow smaller in low oxygen and some grow larger in high oxygen.36PubMed Central. Atmospheric oxygen level and the evolution of insect body size The high-oxygen air of about 300 million years ago was thought to explain the giant insects of that era.37PubMed Central. Atmospheric oxygen level and the evolution of insect body size
Newer evidence challenges the oxygen story. A recent study found insects were never close to running out of oxygen, even at very large sizes.38University of the Witwatersrand. The Breathing Myth That Misled Insect Biology So something else, such as body strength or survival during molting, may set the upper limit.
Growth does strain a big body. Body weight grows faster than the strength of a muscle as an insect gets larger, so small young mantises are proportionally stronger than large adults.39Science News. Female giant rainforest mantises grow up to strike harder than males And a hard outer skeleton must be shed to grow, a vulnerable moment that gets riskier with size.