Along with the predatory Saga katydids, Acrometopa syriaca is one of my favorite katydid species in Israel. There is something unique about its appearance; it almost looks like a tropical katydid that does not belong in the Mediterranean region. This species does not have a common name, so I suggest – “Mediterranean leaf katydid”. In my opinion, there is no other katydid in this area more deserving to be called a leaf-mimic.
When I visited Israel in early spring this year, I could only find tiny katydid babies. They were very easy to recognize as Acrometopa by the pale, extremely-long-yet-thick antennae, which are rich in sensory hairs. Apart from Acrometopa, only Saga species have thick antennae, whereas all other katydid species in Israel have relatively thin antennae.
There is very little chance to mistake adults of Acrometopa syriaca with another katydid species. It is big (can easily reach 12cm leg span, even longer if antennae are included), slow, and rarely jump. Apart from its characteristic antennae, it is always green, and has wide forewings that have both the color and texture of a leaf. This excellent camouflage makes it very difficult to find the katydid when it rests on bushes or small trees. Females are rounder in their appearance, while the males have longer hind wings that extend beyond the forewings. In addition, this species’ huge hind legs are unmistakable.
I just happened to be lucky enough to visit Israel again in early summer, and I was hoping I could find some adults. Even though this species has a relatively wide distribution throughout the country, I drove to the Golan Heights in the north, because I have always been under the impression that they are easier to locate there. But I found nothing. I returned frustrated to the Central Coastal Plain, only to find an adult female very close to the place I was staying at. Obviously, I could not resist the temptation to photograph her for Meet Your Neighbours biodiversity project.
But it was not over just yet, for this katydid was also a fine candidate to test something I wanted to do for a very long time: photography of fluorescence under UV.
I have photographed UV fluorescence of arthropods in the past; scorpions are usually the default subjects for this style of photography, because they show intense fluorescence even under long wavelengths in the UV range (380nm-395nm). This makes photographing “glowing” scorpions very easy with cheap UV torches (you can see examples of such photos in my scorpions gallery).
Things get more interesting under a shorter wavelength, specifically 365nm and shorter. I will not go into details here because I plan to write a bigger post about UV photography, but I will just say that many unexpected things start to fluorescence when exposed to this light, including representatives of several insect groups. I suspected that Acrometopa syriaca would “glow” because other members of the same subfamily, Phaneropterinae, were also found to show fluorescence under 365nm UV light. And as expected, it did not disappoint: when I shone my torch the whole katydid became bright turquoise in color – just stunning!