"How do I tell what gender my Orchid mantis is?"
Male and female Orchid mantids (Hymenopus coronatus).
This is a question we get all the time, but it can be easy to determine through some simple observations. Look for the following three traits:
- Abdominal segments - The most common method to sex any mantis species, at any age, is to count the number of segments on the underside of the abdomen. Of course, getting your mantis to cooperate and stay still long enough to count segments can be a difficult feat! And the younger the nymph, the harder it can be to differentiate the segments, even with a good camera and macro lens or a magnifying glass. Female mantids have fewer abdominal segments than males - in the case of Orchids, females have 6 abdominal segments, and males have 8.
- The "Necklace" - When your Orchid mantis reaches its 4th instar (or L4, meaning it has molted 3 times) or later, the necklace becomes more apparent. At this point, you will see that the female usually has a green necklace, and the male has a brownish-red necklace.
- The "Unicorn Horn" - Also around the 4th instar, female Orchids begin to develop a noticeable bump on their forehead, between the eyes, which takes on a green or yellow hue. Male Orchids, on the other hand, never develop this "unicorn horn", and the forehead remains flat.
Personally, I am a visual learner, so I never fully appreciated these differences until I finally saw them myself. It was always hard for me to find good, clear diagrams on the web; so, now I have made a few of my own to share below.