Natalicola pallida (Westwood, 1837) - or, The Pale Inflated Stinker

During my first year at university, there was a professor by the name of Brian Case; every time I walked past his office door (as he sadly passed away before my second year, I never had the opportunity to take any of his lectures), all I saw on the name-plaque was brain-case. Similarly, every time I see Westwood's name appended to a species, my mind auto-corrects it, and I suddenly relive Evan Rachel Wood destroying a perfectly unassuming glass of wine with a fair-sized chunk of Anthony Hopkins' (presumably simulated) brain - and, in order to get back to where I was, I have to fight to stop wondering whether he was drinking Chianti.

If you haven't seen the first season of Westworld, that may be a (rather major) spoiler, so sorry for that. Equally, if you would rather receive pictures of insects without tangential pop-culture discussion, sorry for that, too. 

Back on topic, and today's insect is a Tessarotomid shield bug. The shield bugs, by the way, comprise the Pentatomoidea, a globally important group of predators, innocuous herbivores, hugely destructive pests (Nezara and friends) and seasonal delicacies (C.M. Dzerefos writes quite regularly about a Tessaratomid treat) that I have, until now, entirely neglected.

Before I blether too much, here it (he, unless I'm mistaken) is: 

Chongwe Distr., Lusaka, Zambia; 03 June 2018, taken with Olympus E-450 and 3 KOOD magnifiers. 

Beyond being popular as foodstuff in some African tribes, the Tessaratomids are mostly known for... well, not much. As with the rest of the Pentatomorpha (a group which includes the previously featured Anoplocnemis and Pephricus), they can, if sufficiently annoyed, blast you with foul-smelling-but-mostly-harmless liquid; being a fair bit bigger than most of their relatives (I did attempt a scale photo, but he objected and I had no desire to be sprayed in the face), they are sometimes called Giant Stink Bugs (imaginitive) or, for their rather wide abdomens, they are sometimes called Inflated Shield Bugs. 

Although I was aware of their existence, having never come across one before the little green gentleman above showed up in my garden, I had come to unconsciously think of them as one of those bizarre groups of interesting looking insects that the South Africans see, but aren't really present in Zambia, so as you might imagine, I could not immediately say exactly who I was looking at. Fortunately, help was at hand.

In his unavoidably fantastic 2009 database of African Pentatomoidea (if, like me, you are on limited internet, do consider signing onto someone else's before you click that link, as it takes you directly to the .pdf), Robertson lists a paltry 41 species (one of which with two subspecies) of this superfamily from Zambia, which is - considering that even the UK, which as a temperate island should be doubly depauperate, has at least 36 species in the superfamily - more than a bit low. That's not actually surprising - as a nation, Zambia has been more than a little neglected: while our 908 species of butterfly probably more-or-less covers our total, and I've yet to knowingly encounter a species not on that list, our stinkbugs have been tragically overlooked by generations of Hemipterologists**.

Beyond the inevitable undescribed endemics (this is Africa, after all), a more reasonable estimate of our total Pentatomoids is probably in the region of 251 - which is to say, there are 251 species (of which 14 have a second subspecies in the same situation, and 3 have a third for 268 total forms) of shield bug that have either been previously recorded in Zambia, or are recorded in such a combination of countries that they most likely also occur in a significant part of Zambia, based on Robertson's database. A further 18 species and 2 subspecies occur in multiple countries on either side of Zambia, but are either patchily distributed in well-trafficked countries (i.e., one or more recorded countries may not be native range, but inadvertent introductions through shipping, etc) or despite their "per-country" range seeming to suggest that they should occur in Zambia, have a distribution which could correspond with habitat types not present in Zambia (e.g. species recorded in a continuous band of coastal nations and no landlocked countries).

I don't really need to go on about all that, though - in fact, if I hadn't only finished going through said database this morning, I could probably have gotten straight to the point that Robertson's list has a solitary species in Zambia, Natalicola delegorguei Spinola, 1850 (link is to Stål's type of synonym Gonielytrum curculiventre) - not the same species as the Encosternum delegorguei Spinola, 1850 that Dzerefos writes about - and six species probably in Zambia. After casting about the web for a possible way to work out precisely who I was looking at without having to either drive into town or, of all things, ask someone else, I came to the conclusion that just to access the papers which might help me identify it, I'd have to shell out over a hundred dollars in either direct-access fees or subscriptions, and was entirely ready to give up.

Even with this face staring at me, I was ready to give up and let the little guy
fester away in my hard drive until that imaginary day when I'm going to be
obscenely rich enough to afford thousands of subscriptions, back-issues
and the postage to Lusaka... 

But then something magical happened. Retreating from journals who think it's fair to charge 25 USD a pop for papers that came out fifty years ago without even letting me see the abstract, I stumbled across Philippe Magnien's Illustrated Catalog of Tessaratomidae, and after a brief getting-to-know-you period, I realised that while his "publications" page did not (unlike some of the other hemiptera databases on the same domain) provide access to much (or any, to be honest) of the listed literature, he had thoughtfully included images of specimens under all but one of the relevant species entries.

As it turns out, Natalicola pallida is structurally quite different from all other contenders; while Piezosternum calidum (Fabricius, 1787), Aplosterna virescens Westwood, 1837 , Selenymenum piriforme Montandon, 1894, Stevisonius acutus Jeannel, 1914, Elizabetha courteauxi Schouteden, 1917,  and even Tessaratoma absimilis Distant, 1893 (more on that in a moment) - not to mention Dzerefos' Encosternum delegorguei Spinola, 1850, which Magnien lists as occurring in Gambia as well as Southern Africa, which could possibly suggest a wider range including Zambia - have rather sloping, unpronounced shoulders similar to those seen on Stål's re-described Natalicola delegorguei type, Natalicola pallida has very broad, protruding shoulder pads that threaten to entirely swallow the head and bury the whole insect in a forgotten time when Ridley Scott wasn't making sequels*.

This is easier to see from above:

Natalicola pallida - same individual, still from Chongwe, but from a better angle
 to see the form of the pronotum. 

So that's that.

More or less.

The less, really, comes down to a few disagreements between Robertson's Database and Magnien's catalog: first, the name itself; Robertson consistently uses Natalicola pallidus and Magnien uses Natalicola pallida; these cannot both be correct, but pallida agrees with the gender of Natalicola (i.e., they both end in "a"), so I've tried to use that; conversely, I am inclined to use Robertson's Aplosterna Westwood, 1837 over Magnien's Haplosterna Westwood, 1837; I treat Robertson as more accurate here because they credit Haplosterna to Stål, which explains why wherever Haplosterna virescens is seen, it is followed by a bracketed (Westwood, 1837) - indicating that the binomial is not the one that Westwood described it under. Magnien brackets Westwood for the binomial, but still credits Haplosterna to Westwood, which - unless Westwood used Haplosterna for a different species earlier in the same paper, but described virescens under Aplosterna (not impossible) - doesn't make sense. Next, which may come down the the 9 years between Robertson's work and Magnien's, Robertson records Tessarotoma absimilis from Tanzania only, while  Magnien records this species from the entire East Coast, as well as Zambia, which is evidenced in a picture of a specimen from "Kafue City, Kafue River, Lusaka Zambie".

I should be very clear, here. I have quite regularly been to and through a place called Kafue, close to the Kafue River, and while it gets dangerously closer to being a far-flung shanty/suburb of Lusaka City every year, it is by no means itself a city. That is not to say that I'm questioning the record itself, I just feel that it's important to note that for anyone who heads to Kafue expecting to find a city, don't.

A final note should be made that while the link to Natalicola delegorguei Spinola, 1850 takes you to the Swedish Museum of Natural History's image of Stål's type, with the name credited to Spinola, 1852, I've use Robertson's Spinola, 1850 as this appears to be correct






*while I profess to having enjoyed Blade Runner 2029 and, yes, Prometheus (Alien: Covenant, however much potential it may have had, is unforgiveable by virtue of it's killing off Shaw to distance itself from fanboy-hate for Prometheus, and its stupid "Gotcha" ending undermining the otherwise touching Walter/Daniels relationship and setting it up for an Alien 3 level of "well, none of that film mattered" sequel) this is actually a nod to the '80s and shoulder pads. Yes, I know that he made other films between those originals and their sequels. 

**which should be a word, because Hemipterology is, and while the general preference is for Hemipterist, I've never met anyone who described themself as a Bioist, Zooist or Entomists; terms like Lepidopterist, Orthopterist and Hemipterist imply fanciers or enthusiasts (which, in fairness, is true for a lot of Lepidopterists), along the lines of Philatelists and Racists, rather than studiers-of. 

The Unequal Conehead, Conocephalus (Conocephalus) inequalis Uvarov, 1928

Conocephalus Thunberg, 1815 is a massive, successful genus, with well over one hundred species across all continents except Antarctica, and the Orthoptera Species File (OSF) recording forty species within Africa. Throughout their range, they - like many members of the subfamily Conocephalinae Krauss, 1902 - are primarily associated with grassland areas, where they can be an abundant and conspicuous feature of the invertebrate community. In southern Africa, where such fat-and-protein rich insects are an important food resource for humans, they are not so valued as the larger Pseudorhynchus Serville, 1838 and Ruspolia Schulthess, 1898, but are commonly more abundant than either.

Neither I nor the folks at the OSF have found any records of this genus from Zambia, but they are definitely here; the pan-African Conocephalus (Conocephalus) conocephalus, first described by the taxonomic powerhouse that was Carolus Linnaeus in his Systema Naturae (1767), is common across the country, and then there is this little guy: 

Chongwe Distr., Zambia, April 2018

Within the African Conocephalinae, the tribes Agraeciini Redtenbacher, 1891 and Copiphorini Karny, 1912 are largely comprised of more robust insects. Additionally, the majority of the Copiphorini have an extended - sometimes markedly - forward point of the head, distinctly beyond the bases of the antennae, and the Agraeciini are almost exclusively recorded from Tanzania and Kenya, with a single species in Gabon and Cameroon.

This leaves for our consideration the tribe Conocephalini Burmeister, 1838; excluding three species of Thyridorhoptrum Rehn & Hebard, 1915, which seem to be limited to areas North of the equator, the Conocephalini in Africa essentially comprises the previously mentioned Conocephalus and the subtribe Karniellina Hemp & Heller, 2010. While the Karniellina do certainly enter Zambia, being recorded from Muchinga, Northern and Eastern provinces so far (more on that another day, hopefully), males in this group have somewhat shorter elytra (the hardened forewings) and an enlarged pronotum (the conspicuous upper part of the thorax), which in all except one genus (Karniella Rehn, 1914; rather distinctive little beasties from Rwanda and the D.R.C.) are twice the length of the wings - which is not the case here. 

So we turn to Conocephalus itself, and shrink in horror. Even if we make the (dangerous) assumption that all species in this genus in Africa have been described, within the continent, this genus is a mess. Our first port of call is to head to the magnificent, wonderful and previously mentioned Orthoptera Species File, which - short of visiting every museum in every country the Southern African Development Community (SADC), and all those in every country that ever sent entomologists or entomologically-inclined missionaries, colonists or mine operators to them - is the most reliable way of finding out which species are where. 

Excluding species that are in Africa geographically, but don't penetrate (oo-er) south of the Sahara; and, to make our initial workload easier, ignoring species that the OSF only has records from West Africa for (for now - as distribution data is fairly patchy still, this can be unreliable at times), we're looking at twenty-five described species to compare. We can immediately exclude the seven bizarre, elongate species of subgenus Megalotheca, which, although they probably are present in Zambia, look more like a piece of grass dreaming of being a katydid than anything else. Knowing we may have to revisit them later, we're going to put the six species for which the OSF's illustrations show long-winged type specimens to one side - tentatively, though, because to add to the chaos, some species of Conocephalus are known to vary seasonally between long-winged and short-winged forms. This still leaves us with twelve species: seven not illustrated at all, and five with short-winged type specimens illustrated. 

One of the five illustated species is Conocephalus (Conocephalus) inaequalis, and the photographs of the type show that, despite being 90 years old, the type still shows much of the colouring of our little chap. This isn't all that meaningful in itself, but when Uvarov described this species in 1928, he also wrote about five of the other species we want to examine or eliminate, so this seems like a promising rabbit-hole to wriggle down into. 

Before we go any further, anyone of a particularly sensitive disposition should probably look away. This is because, in order to describe why I'm moderately confident that we landed through (mostly) luck on the right insect, I have to show you a picture of the business end of a male katydid, and I don't mean the end it eats with.

On the left, you can see the somewhat obscured terminalia of the individual shown near the beginning of all this preamble; he was not overly co-operative, and with it being cold and dark when we met, I didn't check on the quality of my pictures until after I'd gone back inside.  You can, however, just about make out two spines coming off the inside of his cerci (the arm-like structures at each side), although due to the angle and his poorly-placed hindleg, this takes some peering.





Fortunately, back in 2013, I managed to get a picture of a somewhat more co-operative male which shows this a little more clearly; notice the long, black-tipped spine pointing inwards from just behind the blunt tip of the cercus (no, not the type with dancing bears and trapeze artists), and a second one just a little further back from the tip, about half as long.

Well, as it turns out, Uvarov devoted some time to providing illustrations and descriptions of this end of those five little katydids, and both Conocephalus (Anisoptera) rhodesianus (Peringuey, 1916) and C. (A.) bechuanensis (Peringuey, 1916) are quite, quite different: rhodesianus, described from Zimbabwe (then Southern Rhodesia) has single-spined cerci, which bechuanensis has a tiny second spine that doesn't protrude inward, but rather nestles on top of the large terminal spine.

This is progress; all ten of our remaining suspects are within the subgenus Conocephalus. Exciting times (I speak from a highly caffeinated position, so I recognise that others may be less excited by this).

But wait, there's more. Conocephalus peringueyi, which outside of this paper has only ever been mentioned by the OSF itself, is entirely different, without any long, inwardly projecting spines; and on the subject of C.  inaequalis, Uvarov describes it as:

"similar to C. caudalis, differing from it in the structure of the male genitalia, and in the development of the elytra. The latter are longer than the pronotum, reaching to the middle of the abdomen, with the apex parabolic; they are greenish in front of the radial veins with are green, and brownish behind them, with brown spots along the middle... Cercus similar to that in C. caudalis, but its inner teeth are very unequal in size, the one nearer the base being much shorter and obtuse"

Elytra longer than the pronotum - check; they don't reach the mid-point on the abdomen, but the abdomen of your average grasshopper is of quite variable size depending how well fed, out of breath or dead they are, and the pronotum-to-elytrum proportion is consistent with Uvarov's measurements (elytra 1.5 times length of pronotum) - so check; tips of elytra a smooth, u-shaped curve - check; colour characters - check, except that I can't see any clearly marked brown spots; but brown spots on brownish don't sound too visible at the best of times; and cerci - very much check.

Generally a pretty convincing description; the species Uvarov has grouped C. inequalis with, he's also ruled out for us; if we head to Walker's description of Conocephalus  caudalis (Walker, 1869), we can also incidentally take C. tenellus and C. punctipennis out of the running, since both of them have hind wings longer than the fore wings, and if our little conehead has hindwings at all, they're not even long enough to see; his description of C. caudalis turns out to be a dud; he describes only the female, does so briefly, and apparently doesn't bother to illustrate her; the male was only described some time later by Redtenbacher (1891); his illustration (under synonym Xiphidium natalense) confirms what Uvarov implied: the teeth of the male's cerci are equal in size in C. caudalis; from his descriptions, C. africanus (from Gabon) is another long-winged species, so that's ruled out, while his description of C. guineensis (also from Gabon) covers only the female, which is short-winged, doesn't really give us any reason beyond geography to suspect that we're not looking at that species. Not losing hope, we turn to the last two species: Conocephalus brincki and Conocephalus basutoanus, both described Chopard in 1955.

You know how people who'd read all the books George R.R. Martin had written in the series before Game of Thrones aired used to prematurely distrust certain characters who, it turned out, were absolute monsters? I react that way to Chopard. He seems to have spent his life going out of his way to publish papers in journals I do not have access to (even when UNZA Library isn't closed for Cholera); while the type for C. basutoanus (from Lesotho) is illustrated on OSF, and shows that the male has quite different cerci, the type for C. brincki is not illustrated, and so I cannot comment on it. Geographically, it shouldn't be a problem - the single record is from high mountain heath in the cape - but leaving it here, as "probably inequalis, but could be guineensis or brincki at a stretch" feels like an anticlimax. If only there was some authority that had written about the unusual features of inequalis after all these species had been described...

Oh, wait.

Heller et al did exactly that in 2014, regarding a strange little conehead from the Eastern Congo, describing the male as being similar in the structure of the cerci to inequalis, noting that "this type of cercus does not belong to the common ones in the genus (not figured e.g. in the only available multi-species study of the genus by Pitkin (1980) on species of the Pacific area)".

Is it disingenuous that I knew this before I took you on this long and twisted journey? I actually read it after Uvarov's description, but as Heller et al note the absence of stable identification characters for the rest of the African Conocephalus (which I am tempted to interpret as nobody knows where Chopard's descriptions are), I then went through the rest of these species in an effort to reach a slightly greater degree of certainty.

Did I get it? Somewhat. The species was described from an unknown location in South Africa, probably in the Transvaal, and seemingly also eastern D.R.C., and people with more access to resources and far better qualified than I could go no further than I have to identify a seemingly identical specimen; if inequalis-like animals were present in northern S.A. and eastern D.R.C. but nowhere in between, it would seem impossible for this to be a single species; it may be a little naive, but despite sharing Heller et al's concerns, I find myself feeling that stumbling on this little conehead in Zambia adds just a little bit of confidence to their identification.

And it could have been worse: trying to identify male coneheads in Africa may be nigh-on impossible, but the females are even harder; this female, by association with the male above, I'm assuming to also be Conocephalus (Conocephalus) inequalis.

References:

Characteristics of the Karniellina in: Hemp, C., Heller, K.-G., Kehl, S., Warchalowska-Sliwa, E., Wägele, J.W. & Hemp., A (2010). The Phlesirtes complex (Orthoptera, Tettigoniidae, Conocephalinae, Conocephalini) reviewed: integrating morphological, molecular chromosomal and bioacoustic data. Systematic Entomology 35, pp. 554-580

Descriptions of Conocephalus inequalis, C. peringueyi, C. bechuanensis and C. rhodesiensis in: Uvarov, B.P. (1928). Notes on the Types of Orthoptera described by Dr. L. Péringuey. Annals of the South African Museum 25 pp. 341-357

Descriptions of Conocephalus tenellus, Conocephalus caudalis and Conocephalus punctipennis in: Walker, F. (1869). Catalogue of the Specimens of Dermaptera Saltatoria in the Collection of the British Museum part II, pp. 225-423

Descriptions of Conocephalus africanus, Conocephalus guineensis and male of caudalis in: Redtenbacher, J. (1891) Monographie der Conocephaliden. Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien 41 pp. 315-562

and finally:

Support for throwing my hands up in the air and saying b***er it, it's inaequalis in: Heller, K.G., Hemp, C., Liu, C. & Volleth, M. (2014). Taxonomic, bioacoustic and faunistic data on a collection of Tettigonioidea from Eastern Congo (Insecta: Orthoptera). Zootaxa 3785 (3), pp. 343-376.