The praying mantis is recognized globally for its distinctive posture and predatory habits. While males and females may appear similar at first glance, a distinct difference exists between the sexes, known as sexual dimorphism. Understanding these differences is important for observers hoping to identify them or for breeders seeking to pair them for reproduction. Several reliable anatomical and behavioral clues allow for accurate identification.
The Definitive Visual Test: Counting Abdominal Segments
The most accurate method for distinguishing sex involves counting the visible segments, or sternites, on the underside of the abdomen. This structural difference is consistent across nearly all species and can often be used to determine sex even in juvenile nymphs. Female mantises possess six distinct abdominal segments, while males have eight.
To perform this count, the mantis must be viewed from below, as counting from the dorsal side is unreliable. The final segment on a female is broader and larger than the preceding ones, often ending in a point. Conversely, the male’s eight segments are smaller and more uniform in size, with the final two segments being slender. This segment count remains the definitive anatomical test.
Secondary Physical Indicators (Size, Wings, and Build)
Once the mantis reaches adulthood, several other physical characteristics offer secondary confirmation of its sex. Females are larger, heavier, and more robustly built than males. This increased mass and broader abdomen are necessary adaptations for carrying and producing the large egg case, known as the ootheca.
The differences in size extend to the wings, which are fully developed only in adults. Males possess longer, fully formed wings that extend past the tip of the abdomen, allowing for agile, sustained flight. Female wings often terminate around the end of the abdomen or are shorter, sometimes making them incapable of true flight due to their greater body weight.
Antennae
Males have longer, thicker antennae, which are covered in more sensory organs (sensilla). These enhanced antennae allow males to effectively detect sex pheromones released by females over long distances. Females have shorter, more thread-like antennae.
Distinguishing Behavioral Patterns
Beyond physical differences, the sexes exhibit distinct behaviors reflecting their differing roles in survival and reproduction. Males are more active and mobile than females, often flying at night in search of mates. Their lighter, streamlined bodies are optimized for mobility, allowing them to cover greater distances.
Females, by contrast, are more sedentary and rely on ambush hunting, often remaining in a single location. This difference in activity is linked to their temperament; females tend to be more aggressive, particularly when they are gravid and require a steady food supply. This aggression helps them secure the energy needed for egg production.
The need for energy also affects their appetite; females display a more voracious and consistent hunger than males. This high energy demand contributes to the observation that females who are not well-fed are more likely to engage in sexual cannibalism. Behavior provides strong supporting evidence for the anatomical differences observed.