Praying mantises exhibit sexual dimorphism, meaning there is a noticeable difference between the sexes. Distinguishing between a male and female mantis is useful for enthusiasts, researchers, and those who keep them as pets. Accurate sex identification requires focusing on specific anatomical and behavioral traits that become more evident as the insect matures.
Counting Abdominal Segments
The most definitive and reliable method for determining a praying mantis’s sex involves counting the visible segments, or sternites, on the underside of the abdomen. This technique can often be used on sub-adult mantises, typically from the fourth instar (L4) onward, although it requires careful observation. Females possess six abdominal segments, a number directly linked to their reproductive anatomy.
The female’s final segment is notably larger and broader than the others, forming a protective structure around the ovipositor used for laying the egg case, or ootheca. In contrast, male mantises display a count of eight visible abdominal segments. The male’s segments tend to be more uniform in size and shape toward the tip of the abdomen.
Observing the underside of the insect is necessary for an accurate count, sometimes requiring gentle handling. Given the small size of the segments, especially in younger individuals, a magnifying glass or a clear photograph can aid the process.
Differences in Overall Body Size and Shape
Beyond the segment count, the most apparent distinction between the sexes lies in their general morphology. Female praying mantises are larger, heavier, and more robust than their male counterparts. This greater body mass is necessary for the production of hundreds of eggs contained within the ootheca.
The female’s abdomen is notably wider and more rounded, particularly when she is gravid, giving her a stockier appearance. Males, conversely, are smaller, lighter, and possess a slender, elongated body shape. Their streamlined form contributes to their mobility and capacity for flight. These size differences become increasingly pronounced as the mantises reach their final molt into adulthood.
Distinctions in Antennae and Wings
Specific appendages show measurable differences between male and female mantises, particularly after they reach their final adult stage. Male mantises have longer, thicker, or bushier antennae compared to the female’s shorter, thinner antennae. The male’s specialized antennae are equipped with a higher density of sensory organs called sensilla.
These sensilla allow the male to detect airborne pheromones released by the female, which is necessary for locating a mate over long distances. Differences in wing structure are also common and are directly related to flight capability. Adult males have wings that extend well past the tip of the abdomen, and their lighter body weight makes them strong, agile fliers.
Female wings are often shorter, sometimes only reaching the end of the abdomen or being vestigial in some species. Due to their significantly heavier, egg-laden bodies, adult females are often poor fliers or entirely flightless.
Behavioral Differences
Behavioral patterns can provide supporting evidence for sex identification, though they are less reliable than physical characteristics. Male praying mantises exhibit greater activity levels and are more skittish or flighty. Their light weight and powerful wings allow them to spend more time actively searching for females.
Females, due to their larger size and reproductive requirements, are more sedentary. They often adopt a sit-and-wait strategy, relying on camouflage and ambush tactics to conserve energy and secure resources for egg production. Females are also more aggressive than males, a trait sometimes observed during or after mating through the act of sexual cannibalism.