Tuesday 6 December 2016

The Grasshopper without a name (Thericleidae)

The other day, on a group I follow on a popular social-networking site that shall not be named here, someone decided to complain about people answering queries with Latin names; while his initial complaint was mildly annoying, a later comment claimed that those using Latin names were snobbish and just trying to show off their own knowledge.

This is sufficiently absurd within the confines of the group itself, which covered snakes: snakes in the region do, for the most part, have unique common names; but many have multiple common names, which are not universal across their ranges, while the binomal names are universal; that's the entire point. The argument that they are elitist isn't new; the late, great ornithologist Levaillant was a firm believer that colloquial names were all you needed - but he was working with birds.

With insects, it is extremely unusual to find a species which has its very own common name. Sometimes, this applies to the entire family; take for example, this:

Thamithericles croceosignatus (Bolivar, 1914). Photographed in Chongwe District, Lusaka, Zambia; December 2013.

Not only does this colourful little creature not have a unique common name, its family doesn't; most often, they are referred to as Bush-hoppers, a name which also applies to a number of related families, and also some insects in completely separate orders.

The best that I can do (and will occasionally do for complainants on social-media) is find the English meaning of the name; but for that, see the (long-)previous post on a member of this family, Pseudothericles jallae (Griffini, 1897).

Fair warning: this post is about to turn into a tangled complaint about all sorts of things people and the media say; or things I think they say. 



You might - and people do - wonder why we should care about animals that have spent their entire histories so irrelevant to us that they don't even warrant names in Gosh-darned English.

First off, that's racist.

Look at this picture while you think about what you've done to deserve that. 



Harpethericles leechi, Descamps 1977, in New Kasama, South-East of Lusaka City. 






































Have you ever noticed that every single species of grasshopper in the UK has its very own common name? No? Well, they do. This might - in part - be down to how desperately few grasshoppers the UK has (13 members of suborder Caelifera - short-horned grasshoppers - native); but it also has a lot to do with occurring in Europe.

The Thericleidae - the family which we are currently looking at - do not occur in Europe, but are almost entirely limited to Africa.

This is not to say that Africa does not have a long tradition of naming; elderly villagers can have dozens of names for different creatures that the average European would dismiss at a glance as 'spiders', but many of these names have either disappeared or are disappearing - two well-spoken ladies recently racked their brains trying to find the word for butterfly for me after they dismissed the word 'gulugufe' as meaning something entirely different in Zambian Chewa and Nyanja as it means in Malawian Chewa; and despite both speaking several languages fluently, neither could produce a single word (In much the same way as 'Dumbledore' originally meant bumblebees (and occasionally stag beetles and cockchafers) in the UK, and became a term for a village idiot, 'gulugufe' seems to be primarily used in some areas to indicate a fool with no direction in life)

I am tempted, sometimes, to blame this loss of names indirectly on colonialism; even after independence, Zambia's first president, Kenneth Kaunda, resisted suggestion that local languages should be taught in Zambias schools for decades; believing that an entirely English-speaking population would be better equipped to thrive in a global economy. 

On the other hand, much of Sub-Saharan Africa only began writing down their language after the Europeans arrived; and with relatively small populations subject to the ravages of tribal conflict and the intra-African slave trade long before Ghana decided that gold was less profitable than slavery and launched the trans-Atlantic slave trade, keeping names for specific insects that are only occasionally encountered was probably not a priority in most areas.


Pseudothericles jallae jallae (Griffini, 1897) in
Lusaka South, February 2015. 




If this looks like an argument that they still shouldn't be a priority, that's because you're forgetting that tribal warfare and both the trans-Atlantic and intra-African slave-trades have mostly dried up. 

These days, more serious concerns are economic turbulence, voter dissatisfaction and - my personal favourite - environmental decline.

Aha, I hear you say; you have posted three images so far and not a one of them has wings! These creatures must be limited range endemics with narrow environmental tolerances!

How very insightful of you! Well, you've pre-empted my lengthy argument about how their limited ranges and particular taste where it comes to their living conditions mean that they exist on evolution's knife edge, depending on environmental consistency just to carry on existing.




Lophothericles euchore (Bolivar, 1914)
in Chongwe District, Lusaka, Zambia, February 2016.




And you can probably guess that I'm always happy to see them out and about, because they mean that the local environment is - over the broader area - stable. Needless to say, I don't really see them in the large farming blocks.

I do see some in the suburbs (especially Lophothericles euchore (Bolivar, 1914), left)










It also helps that - thanks to a truly fantastic monograph by Descamps (1977; sadly not available online but can be bought from NHBS for a painful price) - they are fairly identifiable.

But enough of this 'everything must be useful' nonsense. Personally, I think they're pretty awesome little creatures. For example, check out the 12 millimetre porcupine that is Uvaroviobia luanensis (Uvarov, 1953). 


Uvaroviobia luanensis (Uvarov, 1953), Chief Nyalugwe's area, Eastern Province, Zambia. 

You may notice the (Uvarov,1953) that follows its name? That's the author who described it, and the year it was described (and it's in brackets because Uvarov did not commit a terrible crime of nomenclatural impropriety and name a genus after himself; that change came later). In this particular case, the year it was described is also the only record of the species that I can find; recorded from the Luano valley - some distance from where I found it, but environmentally very similar - in 1953. 


You're looking at the male (above) by the way. The females look like this (below): 

Female Uvaroviobia luanensis (Uvarov, 1953)  on unnamed tributary of the Luangwa, Eastern Province, Zambia































Another U. luanensis...
Narrow-range endemic, so same area, too.





It's sexually dimorphic. Well, somewhat polymorphic; Females can sometimes also look like this (right): 

Lophothericles burri Descamps, 1977.
Female
In Chief Nyalugwe's area, Eastern Province










Lophothericles burri Descamps, 1977.
Male
In Chief Nyalugwe's area, Eastern Province


Uvarovobia's presence in a second valley system some distance from the site of its original description shows that it is much more widespread than previously thought, and may even extend in to Mozambique. This is even more likely for the larger, more typical Lophothericles burri Descamps, 1977, which co-occured in the same valley, barely a whistle away from the Mozambique border, and is more widely recorded within Zambia.
















They do get more widespread; Stenothericles porcellus (Miller, 1936), the prime suspect for a slightly troubling species from Chongwe (Lusaka), is recorded by Descamps from Malawi and Zimbabwe; curiously, he does not record it in Zambia at all. Of the two species of the genus that Descamps does record in Zambia, Stenothericles rossi Descamps, 1977 and S. zambiae Descamps, 1977, his illustrations of their cephalic (head) and thoracic (um... thorax) structures is quite different from both Stenothericles porcellus and my Chongwe Stenothericles; which might, then, be filling in a gap in an otherwise wide but disjunct distribution.



Stenothericles cf porcellus (Miller, 1936)
in Chongwe District, Lusaka, Zambia, December '13


For those of you who can't bring themselves to fork out for Descamps' Monograph - and I'm not judging you, I know that it can be hard to justify spending money on animals that you will likely never see, even if you are on the right continent - the best free resource on these and any other common-name-less Tsokonombwe (Chewa - Grasshopper) that you happen to be interested in is probably the Orthoptera Species File.

Saturday 3 December 2016

The Thick-Headed Flies - Conopidae


A rather larger - and much more confusing - family than last month's Micropezids, meet the Thick Headed Flies:
Conops (unidentified species) in Chongwe District, Lusaka, Zambia; February 2013.






























These colourful, wasp-like flies have had a tumultous taxonomic history; bouncing between the Aschiza (along with Hoverflies such as Metadon inermis) and the Schizophora (along with the greatest diversity of modern flies, including such oddities as the Stalk-Eyed Diasemopsis meigenii), but while genetics support its relationship to the Schizophora, its position therein remains imperfectly resolved (Gibson et al, 2010); but the family itself has been quite intensely studied (e.g. Gibson and Skevington, 2013).
Sicus ferrugineus Scopoli, 1763,
in Chichester, West Sussex, UK; July 2013.





Their life-habits are fairly remarkable, too; while adults are often found visiting flowers, they spend their larval stages eating other insects - usually bees (as is the case with Sicus ferrugineus Scopoli,1763 from the UK) or wasps of various families; a few species are known to parasitize cockroaches and crickets.








Wasps and bees are by no means an easy target for a fly with a limited physical arsenal; no powerful sting, no heavily-built, piercing mouthparts (which would be somewhat counterproductive, at any rate); and so many get around this problem by looking remarkably wasp-like:

Archiconops pseudoerythrocephalus Stuke, 2004 on banks of Luangwa; Eastern Province, Zambia, April 2015. 




Unidentified Mammoth Wasp (Scoliidae) from Lusaka,
showing similarity of appearance to that of Archiconops
The above Archiconops was closely following a Mammoth-Wasp (family Scoliidae), which itself was probably an external parasitoid of larval Scarab beetles; although Scoliids - unlike may parasitoid wasps - can sting, Archiconops is likely given some protection by its resemblance, allowing it to get close enough to use its scimilar-like ovipositor to rapidly lay an egg between the wasp's thorax and abdomen, and its agility - much greater than the often-bumbling Scoliids - allows it to beat a hasty retreat as soon as the wasp catches on.



 But there are other risks to hyperparasitism; evolutionary risks. While the wasp's populations are at the mercy of fluctuations in beetle populations, and must remain at a relatively low level to ensure that they do not begin to exhaust their host populations, the fly's survival depends both on the wasp and on the beetle, and if either of them has a bad year, the fly's population will plummet - and with reproductive rates necessarily low to avoid causing a crash in host populations, they can take generations to recover, and are rarely - if ever - common.

Conops cf aurantius Brunetti, 1925 in garden in Chongwe, Lusaka, Zambia;
only a handful of these flies will be seen per year even in most rural environments. 


Identification can also prove surprisingly complicated; although the flies are very distinctive as far as flies go - even if they may, at a glance, they may be mistaken for the wasps they mimic - there are a precious few others that can be strikingly similar.


Systropus Weidemann, 1820, is a wasp-mimicking bee-fly (family Bombyliidae)
that can bear a striking resemblance to some Conopids. Chongwe, February 2016. 

Physocephala rufipes (Fabricius, 1781)
in Bosham, West Sussex, UK

The fly immediately above is a Zambian example of Systropus Weidemann 1820, an unusual genus of Bee-flies (Bombyliidae) which, like most Conopids, closely mimics wasps. Physocephala - a very widespread genus of Conopid that also occurs in the region  (although the species shown is the British Physocephala rufipes (Fabricius, 1781)) - can be very similar; and they are probably most easily distinguished by their eyes; in Conopids, these are always widely separated, while in Systropus, they meet at the top of the head.





There are numerous other distinctions, particularly in the dramatic external genitalia of many female Conopids; but the widely separated eyes are a very prominent feature of the Conopids, and help to mark out this (un-cooperative) Conops cf elegans Meigen, 1824 as a member of the family [NB - various flies in various families ALSO have widely separated eyes, but are not nearly so Conopid-looking as Systropus].

Conops cf elegans, Meigen 1824.
Banks of the Luangwa River, Eastern Province, Zambia, April 2015.  

And just to be going with, the European Conops quadrifasciatus De Geer,1776 in a West-Sussex Garden. Although this species was only formally described some 18 years after Linnaeus' Systema Naturae transformed entomology in 1758, the genus - which we have encountered almost throughout this post - is actually one of the first described of all invertebrate genera*, as one of only 10 genera of flies that Linnaeus actually described.

Conops quadrifasciatus De Geer,1776 in Bosham, West Sussex, UK; August 2013.



More details about Conopid life-histories can be read in Gibson's 2011 thesis on the family, which is (unlike the other two Gibson papers) freely available online. 

A good starting place for Conopids in Southern Africa is O. Kröber's The Conopidae of South Africa, in Volume 14 Annals of the Transvaal Museum; this is a very elderly paper, however, and it is always worth checking on the Diptera Nomenclator that the names Kröber uses are still appropriate to species in south Africa (e.g. Conops erythrocephala Fabricius, 1794 in Kröber's work almost certainly refers to Archiconops pseudoerythrocephalus Stuke, 2004)



*Incidentally, and as I was completely mis-explaining to a much-more-knowledgeable entomologist the other day (As a general rule, if I'm trying to explain something genuinely interesting to someone cleverer than me who doesn't know about it, I will forget everything that is inside my head and be embarassingly wrong about everything), Linnaeus Conops - and all his other invertebrate genera - lag behind several European spiders. Although no longer in its original genus, Enoplognatha ovata (Clerck, 1757) - the very first post on this blog - is one of those species which is still listed as being described one year before Linnaeus' Systema naturae, which is officially considered the starting-gun for the binomial naming system in invertebrates - to avoid taxonomists having to trawl through Pliny and older works to see who deserves the truly initial credit, so the whole thing is a bit of a scandal.