Ever since I can remember I have been having a recurring nightmare: I am in some incredible location – usually somewhere in the tropics, there are amazing insects everywhere, often those that I have been dying to find, but I need to leave immediately and have none of my collecting gear – not a single vial, no net, no camera (not everybody can relate, I realize, but entomologists know what I am talking about). And last month I finally got to live through this bad dream.
Before coming to Gorongosa I flew to the northern town of Pemba where a newly opened campus of the University of Lurió trains Mozambican students in biology and engineering. It was supposed to be a strictly-business trip, meeting lecturers and students, and for this reason I did not bring with me any collecting or sound recording equipment, and only the most basic photo gear. But my friend Harith had a better idea and decided to take me on a short trip to Quirimbas National Park, famous chiefly for its spectacular marine life. Some of his students were working on insect and amphibian faunas of the park, and I said, “Why the hell not.” The seemingly easy trip turned briefly into hell after our Mitsubishi truck decided to part ways with its clutch right in the middle of nowhere. After a long while a friendly driver in a passing car went to fetch a tow truck for us, and eventually we made it to the park.
The first thing that I noticed was the wall of insect sound. The lush miombo forest reverberated with loud katydid calls, ones that I did not recognize. They were unusual for a couple of reasons. One, it was the middle of a hot, African day, and katydids tend not to like it, preferring to call under the cover of the night. And two, the calls were continuous, low frequency, and very complex. They were telling everybody with ears, “Here I am, come and get me.” And when you do that you better have a good trick up your sleeve to protect yourself, as katydid ladies are not the only ones listening: birds, lizards, monkeys, they all love big, juicy insects.
The katydids were calling from high in the trees and I was afraid that I would not be able to catch, or even see them. But then one flew down from the canopy and landed right in front of me. When I saw what it was, my heart skipped a beat – it was Pardalota karschiana, the Holy Grail for katydid aficionados (there are a few of us out there). This species had been known only from the original type series, described in 1911 and preserved in a museum in Berlin. What is special about this species is that even those old, dried husks retained vivid, crazy colors, unlike those of any other known katydid species. And colors as awesome as this indicate an equally awesome biology.
I caught the katydid and he immediately went into a defensive mode: he opened his bright purple, black and white wings, and exposed his neon-orange abdomen and cervical membrane; he lifted his hind legs that had yellow and black markings, remarkably similar to those of toxic chrysomelid beetles. This was either a daring bluff, or this thing was seriously poisonous. All around me other males continued to sing.
A video of a P. reimeri nymph – although the insect is not feeding it gives the perfect illusion of the front end of a fuzzy caterpillar chewing on a leaf.
What to do? Here I was, surrounded by a remarkable entomological discovery, but with no way to collect, preserve, or record it. I decided to exploit Harith’s students and we fanned out looking for the insects. Soon we discovered where they sang – they were only calling from, and feeding on, two species of trees, both known to produce potent chemical defenses, including some powerful psychoactive alkaloids. This almost certainly explained their aposematic coloration. We also found nymphs of this species, which turned out to be incredibly hairy. In fact, when I first saw one I thought I was looking at a fuzzy caterpillar feeding on a toxic plant – its movements were an uncanny imitation of the front end of a caterpillar chewing on a leaf, even though I was looking at at the katydid’s butt. It wasn’t shocking then when a minute later I noticed very similar looking caterpillars feeding on the same plant and, also on the same plant, tiger moths (well known to be toxic) wearing colors very similar to those of the katydids’. Having nothing else at my disposal I pointed my Canon 6D at the canopy and used its video recording feature to record the sound of the singing males. I collected as many individuals as I could, stuffing them into Ziplock bags, hoping to be able to get decent photos and proper sound recordings later on.
In the end I managed to collect enough material and data to write a short note about the biology of this species. But not being able to do a very good job at data and specimen collecting in the field was not a pleasant experience. I have already learned never to go anywhere without my headlamp, a GPS, and a camera, and now I am adding to this list an ultrasonic sound recorder and a large set of vials with 96% ethanol. On the second thought, maybe also an extra clutch for a Mitsubishi and a satellite phone. And some beer, for emergencies.
Two nights later I had a nightmare about Quirimbas.
17 Comments Add yours
The coloration of this creature is incredible! I can’t help but envision an alien language written in yellow (Or white?) within the black on each wing. Thank you for sharing these photos with us.
I came across this nice drawing derived from your picture on flickr. You may want to have a look.https://www.flickr.com/photos/antbbx/13688867533/
I love the rune-like yellow marks on the black spots. Perhaps you should give it a common name like “Runic Katydid”.
Re Acripeza, I don’t know of any tests on its toxicity but they do feed on highly alkaloid plants. I’ve always thought that the hemolymph of Acripeza should be looked at but to my knowledge, no one ever has.
Re Pardalota, there are specimens in the Cal Academy collection, collected by ES Ross in several places during his African forays. The colours, of course, are faded but he probably took photos of them. They are all now in the Getty Collection.
That moth looks a lot like an Agaristinae Noctuid, something in the genus Heraclia. African moths aren’t my specialty though, and there are probably a few species in a few Lep families that mimic each-other.
Chris, yes, Heraclia was my first guess, too, but I was told by a Mozambican biologist that they were in fact arctiids.
Absolutely beautiful – and I’m torn between sympathy at the equipmentless scenario described, and ridiculous levels of envy that you consider a 6D inadequate photographic equipment. :)
The behaviour and ecology of this katydid reminds me of our Acripeza reticulata. If it has an orange neck membrane that would really be a coincidence. I understand your excitement–probably just like the first person to see a Quetzal.
David, I imagine that Veria colorata may be equally bright in life (I have never seen a live one) and perhaps also displays a similar behavior? Has anybody tested Acripeza for the presence of any toxic compounds? They clearly must be well defended otherwise they would have disappeared a long time ago.
This is amazing, and I can definitely relate!
What a gorgeous katydid! Have the toxins been characterized yet?