First Brown Morph Mediterranean Katydid Adult

The first of our few interesting brown morph Mediterranean Katydids (Phaneroptera nana) has made it to adult and is still maintains a mostly brown appearance.

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In a post we made about color variation in Mediterranean Katydids (Phaneroptera nana) and Mexican Bush Katydids (Scudderia mexicana) from a while ago on 6/28, we were hoping that some of our brown morph Mediterraneans would stay brown all the way until adult just for their uniquness. In our experience, the brown morph is relatively uncommon in this species with probably only 10% or so of all encounters having this form (sample size of 80+ this year) with the rest being varying shades of green. In the past we had noted that the brown morphs consistently eventually started turning green with each successive adult and were full green by adulthood in the Mexican Bush Katydids so we were wondering whether the same would be true in the Mediterraneans.

As of now, it does seem true but also not necessarily. We still have a handful (4-5) brown morph Mediterranean nymphs that have stayed exactly just as brown every instar since we caught them (absolutely no sign of turning green), though they range in shade greatly (some are a very dark brown, some are pinkish, and some are a golden brown). But today, a golden brown sixth instar finally molted into adult and is still golden brown but quite bit lighter then before -- almost yellow with a tinge of green. It is clear that, given a few more molts, it probably would have eventually turned green. Yesterday when it was about to molt, its wing buds were so swollen and thick that you could almost see the new wings bundled up inside them and they were tipped with a distinctive green pigment. Of course when it actually did molt today and fully expanded out the wings, the green became much diluted as seen in the image. 

We are guessing that it decided to take the green route this final instar, perhaps because we moved it into the new enclosure then with the Blue Morning Glory vine (Ipomoea acuminata). We have noticed when we have encountered katydids in the wild, they often match their food plant quite well, suggesting that the substrate color does influence the color of the katydid to some extent. For example, one of the pinkish brown katydids we found was on a dying grape leaf (Vitis) that was a very similar pinkish brown and a yellowish Mexican Bush Katydid (overall still green though) with thick pink bands was found on a passionflower (Passiflora) flower which was pink and yellow. When we put this golden brown katydid back into the enclosure, it crawled on a morning glory flower bud that had a strikingly similar golden brown color with a tinge of green. 

- Brian