Saturday, 28 June 2014

Enicospilus - Stephens, 1835

National insect week continues!

The japantarra [Central Bearded Dragon - Walpiri] honours this by consuming as many as he possibly can in as short a time as possible. Of course, he does that every week, so it's unlikely that he's actually aware of the event.

Here's one that won't be going down his throat:

Chongwe, Lusaka, Zambia, February 2013. Photographed using Olympus E-420 DSLR, Zuiko 40-150mm lens and 3 KOOD magnifiers.

In Chewa dialects, this - and numerous species both similar and dissimilar - are referred to as Abemberezi (singular form bemberezi), a group of insects of particular benefit to both farmers and scientists; in English - and related languages - these are the Ichneumon wasps.

Their use to farmers is twofold: first, like almost all wasps, the adults are valuable pollinators; second, ichneumon wasps are one of the most diverse groups of parasitoids on land; animals which spend a significant period of their life as a parasite on or within another animal.

This second point is where the ichneumons stand out from other wasps; unlike potter wasps such as Synagris proserpina [link], most ichneumons are rather specific in their choice of baby-food, with any species usually sticking to a particular family, genus or species as a host for their developing larvae.

The upshot of all this is that a farmer having a particular problem with any given insect pest can encourage or introduce a selection of species that are known to preferentially parasitize that species, and, so long as chemical control doesn't wipe out the pest or the parasitoid, their problem will be kept at a manageable level thereafter.

While abemberezi are interesting to scientists in a great many ways, they - along with a diversity of other parasitoids - are of particular value as biological indicators.

You may or may not be aware that the top of the food chain is, in evolutionary terms, a very dangerous place to be. It is. Being fussy at the top of the food chain, although a great way to avoid competitive exclusion, is an even better way to go extinct.

Imagine, if you will, that any healthy population required only eight individuals in that species (which would be very low). If a species is a producer (a plant, algae or various bacteria), it only needs enough resources to be available to support eight individuals. Provided that no competitive exclusion, mass predation or cataclysmic event wipes them out, they'll generally survive.

Now say that a herbivore of about the same size as the plant exists, and it needs a population of, conveniently, eight plants, in order for enough food to support it to be consistently available.

Now we need sixty-four plants, in order to support those eight herbivores.

And those herbivores have a predator, again of similar size and, by a curious coincidence (I like the number eight today), requiring a population of around eight herbivores to eat so that it doesn't eat them faster than they can breed (and yes, this is a laughably low figure). That means we need at least sixty-four herbivores to support our predator, and its seven colleagues, and 512 plants.

We are, of course, assuming that these plants, herbivores and carnivores are the only species around and lack disease and exist in a perfectly stable environment.

In this environment, we could perhaps expect a tertiary consumer, or top predator. Think about eagles preying on falcons, or wolves eating pet dogs. That sort of thing. Anyway, the same rules apply about how many need to be around for him to not eat them too fast.

Anyway, this now gets to 4096 plants that need to be alive and well at any given time.

So now, we introduce the real world.

Populations fluctuate. A surprise abundance of plants due to good rain one year means that the rabbits are healthy enough to have an extra litter and double their numbers. Before fox populations can respond, the rabbits have eaten the plants down to their roots and after the winter, only 130 rabbits have survived.

Bad news for the foxes, only sixteen of whom can survive this famine, although, on a happy note - given how dispersed the foxes are within the environment at this stage - not even the two wolves who might theoretically have managed to survive on this population can forage efficiently, so these surviving foxes do quite well for themselves, and only one wolf makes it through the winter.

Oops. No more wolves. Ever.

This is not a real world example. But it serves its purpose well; no matter how fragile the situation gets in the lower levels, the most dangerous place to be is always the top. This used to apply to business, too, until the British Government started bailing out failing giants at the taxpayers expense...

But I digress.

As a parasitoid is essentially a specialist predator, it is in an extremely fragile position and, although some species may thrive in disturbed environments, a diverse assemblage of parasitoid wasps is usually a good indicator of an intact invertebrate fauna - which itself is an indicator of high-value habitats worthy of protection and/or study.

That has to be the most words it has ever taken anyone to get to the point.

Anyhow, this wasp is a member of the vast genus,

Enicospillus
Stephens, 1835

And as such, probably parasitises a selection of Noctuoid moths (such as, but probably not its actual host, the Erebid Laelia robusta [link]). 

Also, it's somewhat bizarre and alienesque. Here's another picture, to give you more of an idea of its form:


And that, folks, is all.

Thursday, 26 June 2014

Catopsilia florella (Fabricius 1775)

Four days into national insect week, it seems as though it would be atrocious if I allowed the long-standing funk I seem to be in to stop me from posting something appropriate.

I had planned a lengthy discourse with tons of pictures of invertebrates, but focusing on anything lately has not been very doable (you may have noticed, in the unlikely event that you read through it, that the lengthy taxonomic notes have disappeared from recent posts. Which makes navigation harder, but saves about half an hour of distractedly re-doing the same thing.

Anyway, whining over, meet today's guest:

Lusaka City, Lusaka Province, Zambia, in October 2011. Photographed with Olympus E-420 DSLR, Zuiko 40-150mm lens and 3 KOOD magnifiers.
This soft-touch of an entry to a blog supposedly focusing on under-loved groups (in my defence, it was suggested by a random number generator) is one of Zambia's many Agulugufe (Chewa - plural of gulugufe), but is far from endemic; it extends through most of Africa, including island nations such as Madagascar and the Canary islands - which, having remained a territory (=colony) of Spain, is often used by entomologists to say that the butterfly is found in Europe. A little bit like saying that penguins breed on British shores when they're actually in the Falklands, but I digress.

This gulugufe is also found as far east as India and Sri Lanka (பட்டாம், ~Pattaam in Tamil; तितली, ~Dtidt(a)li in Hindi), and just in case you hadn't worked it out from the picture, the English term is Butterfly. 






As an etymological aside, one Chewa term for these distinctly user-friendly insects is Peperu, which is, to my ears at least, surprisingly close to the French Papillon.

As with a lot of insects which are not particularly edible, a common name specific to the species is difficult to find in Chewa; the most direct translation from the English '[African] Migrant' I can find is Matchona, which means migrant workers, and, by its structure and the persistent use of Zimbabwe in the example usages, would seem to refer even more specifically to members of the Shona people of Zimbabwe, who make up a considerable proportion of migrant workers in Zambia and Malawi.

So I am forced to think more broadly for a Chewa name to reflect the nature of these insects; Mlendo, which translates most directly to Guest, but can also mean Stranger, Tourist, Foreigner or Traveller, seems the most appropriate.

Our Mlendo Gulugufe can be referred to, internationally, as

Catopsilia florella
(Fabricius, 1775)

Within the butterflies, it is in a generally not white subfamily (Coliadinae) of the 'White' Butterflies (gugulufe loyera), the Pieridae, of which only one other butterfly has thus far been featured, the also not-white (but in the largely white-ish subfamily, Pierinae) Eurasian Orange-Tip, Anthocharis cardamines


Same as opening image, but only 1 KOOD magnifier.
As with most butterflies, there is sexual dimorphism (males and females look different), but with the Mlendo Gugulufe it is imperfect; while the individual to the right(the same one pictured at the top of the post) shows a colour form found in both males and females, the more cryptic colouring  of the specimen below is only known from females. 

Photographed in Chongwe, Lusaka, Zambia, in February 2013, using Olympus E-420 DSLR and 40-150mm Zuiko lens with 1 KOOD magnifier.







And that, folks, is all.









For the identification of large and distinctive African butterflies, the most comprehensive guide I've found affordable is Steve Woodhall's Field Guide to Butterflies of South Africa, published through Struik and available through Amazon (here). As I remain the world's biggest fan of free information, I can't go without mentioning the late R. C. Dening's collection, which, although not as user friendly, is more appropriate to Zambia and, key point, freely accessible online (click here to visit it).

Saturday, 21 June 2014

Podiceps cristatus (Linnaeus, 1758)

It's nearly National Insect Week.

This, by the way, is not an insect.


Attenborough Reserve, Nottingham, UK, in June 2014. Photographed using Olympus E-420 DSLR and Zuiko 70-300mm telephoto lens. Edited using GIMP to remove unwanted element from bottom right corner.


I know, it's a long unbroken string of vertebrates, which is somewhat biased, but that's life.


This lovely bird is, however, quite important for British insects.

It, like most British wildlife with any hint of the exotic in its appearance, was almost wiped out through overhunting. It was fortunate in its timing, however, as the peak of its destruction coincided with the existence of one Emily Williamson, who, in 1889, began a campaign to put life before fashionable hats.

This, to avoid unnecessary drama, was the foundation of the RSPB, one of several organisations now responsible for a large number of Britain's nature reserves and, despite some questionable management choices in some reserves, a major player in the conservation of the diversity of British insects.



The tenuous link to the upcoming insect week is not the only interesting thing about this lovely bird; it's also extraordinarily adapted to an aquatic lifestyle; their legs, perfectly positioned for swimming, are completely inappropriate for supporting the adult's weight on dry land, and cannot do so for more than a few steps.

This presents an obvious problems; watertight though they are, the amniotic membrane cannot usually absorb enough oxygen to sustain a growing bird if it's partially or wholly submerged. A nest on the immediate edge of the water, which would allow a bird limited to the water easy access and escape, is extremely vulnerable to changing water levels, which would limit the birds to extremely stable environments.

This bird, however, survives - and arguably even thrives - all over Europe, Asia, Australia and parts of Africa, and breed in a number of areas where water levels are rarely reliable.



So they build a nest that maintains a constant distance from the water, by building their nest on top of the water, and when their chicks hatch, the first order of business is teaching them to swim.



Nottingham, July 2013. Olympus E-420 DSLR and 70-300mm Zuiko lens.



This comes in an act of rather heartless parenting. First, they give the babies a tour of the neighbourhood while perched on Daddy's back. Once they're used
  

to this, Daddy swims away and leaves the babies to work out how to get back to him.

Still, it's not all bad - the chicks seen in the photograph to the right were several weeks past water-dumping age, but were still allowed to pass a lot of their time enjoying the scenery from the safety of their parents wings.






So what, drumroll please, is this mystery bird? Why, it's the great crested grebe (Puteketeke in New Zealand's Maori language; Kuifkopdobbertjie in Afrikaans; or Grèbe huppé  in French),

Podiceps cristatus  

(Linnaeus, 1758)

And that, folks, is all!

Friday, 9 May 2014

Chamaeleo dilepis, Leach, 1819

Welcome to a bit of a picture heavy post.

This lovely lizard is the subject of a bit of a family obsession:

Photographed in Chongwe, Lusaka, Zambia in December 2013, using Olympus E-420 DSLR
and Zuiko 70-300 telephoto lens.

As far as current knowledge goes, this is the only member of its family native to the Lusaka area. A significant chunk of my school time was spent retrieving these lizards from the centre of a panicked crowd and removing them to a safe distance.

There is a widespread distrust of chameleons in Sub-Saharan Africa - in Lusaka, the traditional myth seems to be that if you are bitten, you are cursed and one of your family is going to die. In the city, this is generally transmuted to their being highly venomous, or harbouring deadly bacteria on their teeth - All of which is patently not true. An angry specimen, with sharply defined markings and throat inflated to show brightly coloured skin usually hidden in folds, can look quite imposing, but having handled countless terrified individuals through my life, and been bitten well over twenty times (my father, notably, once demonstrated their harmlessness by allowing one to bite him on the tongue), I can confirm that it's bite is less painful and no more dangerous than being pinched by someone with medium-length fingernails. 

Have a look at another individual pretending to be twig while I babble about language:


Chongwe, Lusaka, Zambia in October 2011, using
Olympus E-420 with 40-150mm Zuiko lens



I'm not familiar with any Afrikaans names for this creature - a Chewa term is Birimankhwe, considering the more-or-less interchangeable nature of  'L' and 'R' in many Zambian dialects, its Soli name of Bilimankhwe is essentially identical. Kalilombe and Likakatuwe (both Chewa) are usually for larger specimens; Nanzikambe and Tonkhwetonkhwe are also listed by my Chewa dictionary, although I don't recall hearing either of these, or Likakatuwe, in use.



A closely related species is present in southern parts of Europe; in Spanish, Camaleón, which is more-or-less representative of most European names for this lizard (including the English Chameleon).

Further east, a number of species are found on the Indian subcontinent, and the Tamil  பச்சோந்தி

(~Pachonti) is possibly my favourite non-Zambian name.

The only species known to be present over much of Zambia, and extending across most of Sub-Saharan Africa, in English this is known as the Flap Necked Chameleon; internationally, it is most reliably referred to by its Linnaean binomial, which is:

Chamaeleo dilepis
 Leach, 1819



As previously noted, no other Chameleon species are known from most of Zambia (with the exception of a Nyika plateau endemic) - which, given the diversity of species in East Africa and Southern Africa, is possibly due to a lack of any real study rather than a missing diversity. Tellingly, in a country which is naturally forested, the only known chameleon is one of the least forest-dependent of the non-dwarf chameleons, and may simply have been the only species to survive widespread deforestation - often by fire in the inhabited portions of the country.




Although it is most readily encountered moving between trees, it is not limited to . Eggs, as with several other chameleon species, are buried underground, and, in areas with a marked winter season, won't hatch until a year later.

Smaller juveniles - like this hatchling from Chongwe - seem much happier on the ground than adults. This one was found sleeping on a grass-stalk a couple of feet above the waterlogged earth during a thunderstorm (only feet from the previously posted Zonocerus elegans) in January 2014.


Although individual colour changes are usually limited to darker or lighter tones of a base colour, with an increased apparency of dark stripes and spots being the common reaction to a human approach, the species displays an extraordinary diversity in individual colours; from rusty orange (Chongwe, October 2011)  to a lime green (Chongwe, March 2013):

















Although abirimankhwe are generally of quite sensitive temperament, young individuals are often not overly concerned when handled - although the polka-dot appearance of the specimen in the right hand image is an indicator of stress, less than a minute later, it was comfortable enough to catch a grasshopper from its perch on my index finger.

Despite a dark spotting being associated with distress, this large female - bright green and darkly spotted when found trying to hide from passing cars on a road, fading to a leafy green before her release - seemed to grow darker as she headed for the canopy of a large tree, in a quite different pattern to her (not photographed) distress speckles:


Photographed in Chongwe, Lusaka, Zambia in September 2011,
using Olympus E-420 DSLR and 40-150mm Zuiko lens.

And with that rather lengthy preamble, and a record six pictures in one post, on with the taxonomy:

- Chamaeleoninae
- Chameleonidae    
- 'Acrodonta'            
 A bit of a questionable taxon, but see also Agama armata
 - Iguania                      
As noted in a recent reptile post, things get iffy and unsatisfactorily named here. The next grouping on from Iguania is with snakes and allied groups - for which see also Psammophis mossambicus and Thelotornis capensis; and thereafter with the Skinks and wall lizards (e.g. Afroablepharus wahlbergii, Trachylepis varia ,Trachylepis striata wahlbergi and Zootoca vivipara) and eventually the geckos (for example Lygodactylus capensis). This completes the:
- Squamata                       
- Lepidosauria                   
- Lepidosauromorpha         
- Sauria                                 
- Diapsida                                  
- Romeriida                                 
- Reptilia                                      
- Amniota                                      
- Reptiliomorpha                             
- Tetrapoda                                       
- Sarcopterygii                                    
- Osteichthys                                       
- Teleostomi                                          
- Gnathostomata                                     
- Vertebrata                                              
- Craniata                                                  
- Chordata                                                  
- Deuterostomia                                           
- Nephrozoa                                                   
See also Nephila fenestrata, Enoplognatha ovata, Argiope bruennichi, Alopecosa barbipes, Phrynarachne rugosa, Hyllus argyrotoxus, Enoplognatha ovata, Argiope bruennichi, Pardosa amentata, Dysdera crocata, Dicranopalpus ramosus, Ligia oceanica, Dichtha inflata, Oedemera nobilis, Otiorhynchus atroapterus,Malachius bipustulatus , Phyllobius pomaceus, Cheilomenes lunata, Melolontha melolontha, Neojulodis vittipennis, Demetrias atricapillusAnthia fornasinii, Lophyra cf. differens, Synagris proserpina, Vespula germanica, Astata tropicalis, Anthophora furcata, Andrena nigroaenea, Zebronia phenice, Crambus pascuella, Nemophora degeerella, Sphinx ligustri, Laelia robusta, Acada biseriata, Metisella willemi, Anthocharis cardamines, Papilio demodocus, Panorpa germanica, Chloromyia formosa, Senaspis haemorrhoa, Helophilus pendulus, Episyrphus balteatus, Metadon inermis, Diasemopsis meigeniiDolichotachina caudata, Megistocera filipes, Pephricus, Grypocoris stysiRanatra, Anoplocnemis curvipes, Idolomantis dentifrons, Sibylla pretiosa, Tettigonia viridissima, Stictogryllacris punctata, Enyaliopsis, Zonocerus elegans, Humbe tenuicornis, Lobosceliana loboscelis, Cyathosternum prehensile, Heteropternis thoracica, Pseudothericles jallae, Enallagma cyathigerum, Pseudagrion hageni, Lestinogomphus angustus, Rhyothemis semihyalina, Orthetrum brachiale and Burtoa nilotica.
  - Bilateralia                                                        
- Eumetazoa                                                        
- Animalia                                                             
- Eukaryota                                                            

And that's all folks!



My sister, whose primary vocations are more creative than mine by far, also has a thing for chameleons, and much of her art - including several commissions - features these wonderful lizards.
See a limited selection of her artwork online at laurenvanniekerk.artweb.com





Monday, 5 May 2014

Zonocerus elegans (Thurnberg, 1815)

Today, that is to say the 5th of May, is surprisingly enough the date of the annual Cinco de Mayo celebrations in the US and Mexico, which - despite a series of five second films from a Los Angeles comedy group that suggest its origins are unknowable - celebrates a key Mexican victory over French forces in the American Civil War.

I've never been to Mexico. Neither has this:

Photographed in Chongwe, Lusaka, Zambia in January 2014, using Olympus E-420 DSLR, Zuiko 40-150mm lens and 2 KOOD magnifiers.

This delightful - unless you're trying to grow certain crops - Mnunkhadala is a widespread Sub-Saharan blubber-locust which can very occasionally reach densities sufficient for it to become a minor pest, but usually inflicts no real damage on the broad-leafed plants it feeds on. Mnunkhadala is quite a specific name: typically translated just as the English name of this species - the Elegant Grasshopper - which can also refer to a closely related species from West Africa, where Chewa-derived languages and dialects are not native. I'm uncertain as to whether the Chewa term also refers to other blubber locusts, distinguishing them from similar, less toxic true locusts, but I digress.

The link to Cinco de Mayo is a bit tenuous - Mexico's national Arthropod is the grasshopper (Chapolin in Náhuatl; Saltamontes in Spanish). Although on occasion Chapolin refers to a specific edible genus (and the species featured today is notably inedible), I, having never been to the New World, lack pictures of that genus, and this one's vibrant colouring put me in mind of what I've seen of Mexican artwork. 

As a further view, here's the whole insect: 

Same grasshopper, same day, same place. One less KOOD magnifier, I think.



As previously noted, a lot of locusts (from various parts of the family Acrididae) around the world are edible, and in both Mexico and Zambia, can be a major source of protein in rural areas. 

The Blubber Locusts, family Pyrgomorphidae, are generally not edible. They generally eat toxic plants, and built their own chemical arsenal by retaining those toxins in their tissues - as is advertised by their generally vibrant colours. 











As I now have to return to my actual job, I'll add the taxonomy and links later, and for now just note that to avoid the confusion of language, this Mnunkhadala's Linnaean binomial is:

Zonocerus elegans
(Thurnberg, 1815)

So with that, have a good Cinco de Mayo, be nice to some grasshoppers, and that is all (for now) folks! 


Saturday, 3 May 2014

Psammophis mossambicus (Peters, 1882) and a lengthy ramble on reptile taxonomy.

I think it's worth telling you that I am terrified of a fair few things.

One is being alone in water deeper than a foot. Crocodiles are another. Sharks were, for a while, and it's not unreasonable to suppose that the cold dread I experience when I'm swimming in a murky creek without anyone to use as a human shield is because I watched Jaws well before I was old enough.
I'm scared of being trapped in a crowd - hearing more than a couple of simultaneous conversations nauseates me. I'm not comfortable sharing silence with strangers - when I was alone in a windowless lab with a lovely Welsh girl, working on my BSc dissertation study while she worked on her MRes, I was absolutely terrified of her until we broke our respective silences, and I knew that she wasn't just sitting there judging me and/or plotting to kill me somehow
I don't like having people in my blind spot, even if they are talking. I love cliff-top walks, but if I'm within four feet of the edge and I have my shoes on, I find it extremely difficult to step forward (as an aside, if I find myself within six or so feet of water that may contain a crocodile, I have quite the opposite response, and find it difficult to stop running).
I get nervous around powertools - too many scary movies too early - and the sound of trains in the dark. Dogs I don't know, other people's parents, other people's spit, rollercoasters, the Knife-Edge bridge at Mosi-oa-tunya, touching food that other people will eat... I could go on.

This, though, is something that has never been an issue for me:

Photographed in Chongwe, Lusaka, Zambia in August 2011, using an Olympus E-420 DSLR and a Zuiko 40-150mm lens.

Europe doesn't have many snakes; Britain has only three, and as you might expect from this, not until really quite recently has it expanded its vocabulary to include species-specific names - even words such as the Greek-rooted 'Python' have only been in English for a couple of centuries.

Zambia has around seventy species of snake, some of which are harmless, some of which are potently venomous - some of which again will bite readily if they perceive a threat, some of which are unwilling to bite even if trodden on. Some will raise a hood and spit at people a few metres away but flee from people close by, similar species will raise a hood but not spit at a certain distance, but just strike if surprised close to.

The long and short of this is that there are a lot of words for specific snakes in Chewa and its sister-languages. The mildly venomous (nausea and mild to intense pain) species pictured above has the name of Chidyamsana in Chewa, or the Olive Grass Snake, Mozambique Whip-Snake or Mozambique Whip-Snake in English.

It's quite retiring, as one might expect from a small, thin snake, but if cornered will capitalise on its resemblance to the not-too-distantly related Black Mamba (Dendroaspis polylepis), and strike readily. As noted, it's not absolutely harmless, and with a good bite, could make you feel fairly sorry for yourself for a while, but, allergic or psychosomatic reactions notwithstanding, it's far from deadly.

Unfortunately, that resemblance that sometimes means it can send its attackers running now often leads this handy member of the suburban rodent - and indeed snake - control crew to be hacked to death.

Although it is readily confused with smaller specimens of the (much bigger) black mamba, it's shape is quite unlike it - very slender, and often appearing much longer than it actually is as a result, it more closely resembles the arboreal (and rarely seen) green mambas in form; its head, if seen from any angle other than the front, is easily distinguished by its short, pointed form (as opposed to the elegant elongated octagon of a mamba's head, aptly described as 'coffin-shaped' from above). Behold:





It might be better if I had a picture of a mamba to compare it to - I don't, but ARKive hosts a number of pictures (click here to visit them) of the species, which show the difference quite clearly.









With those points covered, it's probably time for the taxonomy. The snake itself is

Psammophis mossambicus
(Peters, 1882)

But from here on, it can get messy.  

Snake taxonomy, by the way, is made atrocious by the existence of that enormous waste-bin taxon heretofore known as the family Colubridae, and in an attempt to reflect the actual relationships between snake species, I seem to be using a taxonomy that isn't necessarily used anywhere else; I put this lovely snake in the:
- Psammophiidae
 which is usually treated as a subfamily of the troubling family Lamprophiidae - which is itself still treated by some as a subfamily of the afore-mentioned Colubridae. I'm treating them instead as a sister family within the
- Elapoidea                 
(along with all manner of snakes we'll be discussing in later posts). This is united with the majority of familiar snakes in the:
- Caenophidia              
which does include the various colubrids - although most are venom-less constrictors, the only one featured on the blog thus far is the venomous  Thelotornis capensis. These are united with the boas and pythons in the  
- Alethinophidia        
  which excludes only a very few rather divergent members of the larger:
- Serpentes                  
Which are somewhere in the taxonomic mess otherwise known as the
-Squamata                     
Within which, the snakes cluster with the iguanians (such as Agama armata ), followed by the skinks and wall lizards (e.g. Afroablepharus wahlbergii, Trachylepis varia ,Trachylepis striata wahlbergi and Zootoca vivipara) and eventually the geckos (for example Lygodactylus capensis). All this falls within the:
- Lepidosauria                   
of which the only other extant group is the New Zealand endemic order Rhynchocephalia, the two species of Tuatara.
- Lepidosauromorpha          
- Sauria                                 
Although after this, the taxonomy gets a little more straightforward, this contains the Archosaurs (Crocodiles and dinosaurs, including birds such as Caprimulgus pectoralis, Tockus alboterminatus, Larus argentatus, Sterna hirundo, Burhinus vermiculatus, Troglodytes troglodytes, Megaceryle maxima, Ardea goliath, Chalcophaps indica and Stigmatopelia senegalensis), and should really include the Anapsids - tortoises, turtles and various dead relatives. But that's another story. 
- Diapsida                                  
- Romeriida                                 
- Reptilia                                      
- Amniota                                      
- Reptiliomorpha                             
- Tetrapoda                                       
- Sarcopterygii                                    
- Osteichthys                                       
- Teleostomi                                          
- Gnathostomata                                     
- Vertebrata                                              
- Craniata                                                  
- Chordata                                                  
- Deuterostomia                                           
- Nephrozoa                                                   
See also Nephila fenestrata, Enoplognatha ovata, Argiope bruennichi, Alopecosa barbipes, Phrynarachne rugosa, Hyllus argyrotoxus, Enoplognatha ovata, Argiope bruennichi, Pardosa amentata, Dysdera crocata, Dicranopalpus ramosus, Ligia oceanica, Dichtha inflata, Oedemera nobilis, Otiorhynchus atroapterus,Malachius bipustulatus , Phyllobius pomaceus, Cheilomenes lunata, Melolontha melolontha, Neojulodis vittipennis, Demetrias atricapillusAnthia fornasinii, Lophyra cf. differens, Synagris proserpina, Vespula germanica, Astata tropicalis, Anthophora furcata, Andrena nigroaenea, Zebronia phenice, Crambus pascuella, Nemophora degeerella, Sphinx ligustri, Laelia robusta, Acada biseriata, Metisella willemi, Anthocharis cardamines, Papilio demodocus, Panorpa germanica, Chloromyia formosa, Senaspis haemorrhoa, Helophilus pendulus, Episyrphus balteatus, Metadon inermis, Diasemopsis meigeniiDolichotachina caudata, Megistocera filipes, Pephricus, Grypocoris stysiRanatra, Anoplocnemis curvipes, Idolomantis dentifrons, Sibylla pretiosa, Tettigonia viridissima, Stictogryllacris punctata, Enyaliopsis, Humbe tenuicornis, Lobosceliana loboscelis, Cyathosternum prehensile, Heteropternis thoracica, Pseudothericles jallae, Enallagma cyathigerum, Pseudagrion hageni, Lestinogomphus angustus, Rhyothemis semihyalina, Orthetrum brachiale and Burtoa nilotica.
  - Bilateralia                                                        
- Eumetazoa                                                        
- Animalia                                                             
- Eukaryota                                                             


And, taking the first exit I can see at this point, that is all, folks! 


                                                      

Friday, 2 May 2014

Nephila fenestrata, Thorell, 1859, or possibly N. senegalensis (Walckenaer, 1842), and a warning for the phobics.

I have mentioned before that I'm quite fond of spiders, and it's probably been apparent in those posts that I am a touch unsympathetic towards people who have worked themselves up so much about something essentially harmless that they'll even hide from an image...

I wasn't always that way. When I was about 8 years old, my dear uncle informed me that the brownish spiders building their webs in the shower were close relatives of the black widow, known as brown button spiders and possessing extremely potent venom. This wasn't entirely dissimilar to something bearing a resemblance to the truth, and this little seed of information threatened to grow into a full blown phobia, before I gained a house-mate who overreacted to wasps in much the same way.

Nevertheless, as this is a member of one group of spiders that I still would be quite uncomfortable handling, I will give spider-fearing men - and women - fair warning: You might not want to look at the pictures.

I will leave it up to you whether you let an irrational fear own you, or take that fear and punch it repeatedly in the face, saying 'Hey, you, fear! Listen up - spiders are extraordinary and valuable members of society, and even if I don't want to touch them, I'm not going to freak out over a bunch of pixels on the interweb. Yeah, I said web, fear, because I'm not afraid of pixellated silk!'

Or something to that effect.

I think that's enough pre-amble that real fraidy-cats should be able to click away without seeing the Kanguade (Chewa for spider) of the day:




You may notice that the pictures on this post are without caption; they are all taken in Chongwe, Lusaka, Zambia, scattered through February and March 2013, although the spider itself is present from the middle-to-late rains (in the late season of the 2013-14 rains, they only showed up in Chongwe in December), and usually persist until July or August.

Unfortunately, this means that all these photographs feature incompletely mature individuals, which can make I.D. a little tricky. For example:

The distinct yellow 'window' on the underside of this little lady would comfortably identify her as

Nephila fenestrata
Thorell, 1859

Also known as the black-legged Nephila (The genus' actual common name, 'Golden Orb-Weaver' is longer than the genus name itself, so we'll stick with Nephila), or Windowed Nephila which has a number of subspecies - and some pictures online certainly resemble this series, but whether those actually belong to this species, or are just hopeful I.D.s by people who've taken the stance that this is more windowed and black legged than it is red-legged or banded legged (the two most promising alternative species; also, in a not entirely unrelated note, the other two species present in numbers in South Africa, arguably the most comprehensively-studied microfauna in Sub-Saharan Africa)

But both these pictures were taken in shady areas, which necessitated the use of partial flash - which masks the translucency of parts of these oversized spiderlings' (okay, a little beyond spiderling) bodies. Which brings us to the third picture: 


This one, as you can probably tell, was caught in early-morning sunlight, which didn't simply allow us to see the transparency of the legs, but it's exaggerated it somewhat, while, to an extent, masking the brushes of dark red hair on three pairs of legs; without that, it seems as though it could grow into an adult Nephila inaurata, or Red-legged Nephila (it can't - there are other more convincing differences in colour and range). 

Even with the brushes, it's not an excessive stretch of the imagination to translate this to the colouring of Nephila senegalensis, which other people of uncertain credentials have done online. 

And, if we take a look at this larger subadult - losing a battle to a Sphecid wasp (probably Sceliphron sp.), we see more of that non-black colouring on the legs: 


The windowing of the abdomen is also reduced to two yellow lines, and the ratio of black to orange on the palp - the little mouth-leg held in the wasps mandibles - is different from each of those seen in the younger individuals already shown, but - as with all the individuals photographed, the femorae (first long bit) of all legs are black - whereas in all images of N. senegalensis I can find on the web or in my (rather limited) books, from Kenya to South Africa, the last (and usually second last) femur is orange-red. 


Two things prevent me from ruling out either of these species. 

1) They are known to be variable, and patterns in adults aren't always readily extrapolated from subadult patterns.

2) It's possible that, despite the saturation of the environment to the point that the dense populations of these spiders weren't separated by more than two or three metres within the entire area these were photographed, there were multiple species, and possibly even hybrids, in the mix.

Until I go out for longer, and get a more continuous series of photographs of the a specific web-group over time and into adulthood (Wasps' and Bulbuls' appetites permitting), I will favour N. fenestrata for these images, but be unable to rule out N. senegalensis. 

I'll add the taxonomy tomorrow - now, with a quick illustration of why these are known as Golden Orb Weavers, I'm off to bed. Behold their silk: 



Yup. It's a rich yellow colour, poetically known as gold. Not really noticeable on fine strands most of the time, but on the thicker threads that anchor the webs, it's a handy clue that you're looking at Nephila.










And, for now, that's all, folks: Goodnight.

Additional: here's the taxonomy.



- Nephilidae                     
- Araneoidea                      

- Entelegynae                       
- Araneoclada                        
See also Dysdera crocata
- Neocribellatae                       
- Araneomorphae                       
- Opisthothelae                             
- Araneae                                        
- Megoperculata                                
- Micrura                                              
- Arachnida                                            
See also Dicranopalpus ramosus
- Chelicerata                                            
- Arthropoda                                             
See also Ligia oceanica, Dichtha inflata, Oedemera nobilis, Otiorhynchus atroapterus,Malachius bipustulatus , Phyllobius pomaceus, Cheilomenes lunata, Melolontha melolontha, Neojulodis vittipennis, Demetrias atricapillusAnthia fornasinii, Lophyra cf. differens, Synagris proserpina, Vespula germanica, Astata tropicalis, Anthophora furcata, Andrena nigroaenea, Zebronia phenice, Crambus pascuella, Nemophora degeerella, Sphinx ligustri, Laelia robusta, Acada biseriata, Metisella willemi, Anthocharis cardamines, Papilio demodocus, Panorpa germanica, Chloromyia formosa, Senaspis haemorrhoa, Helophilus pendulus, Episyrphus balteatus, Metadon inermis, Diasemopsis meigeniiDolichotachina caudata, Megistocera filipes, Pephricus, Grypocoris stysiRanatra, Anoplocnemis curvipes, Idolomantis dentifrons, Sibylla pretiosa, Tettigonia viridissima, Stictogryllacris punctata, Enyaliopsis, Humbe tenuicornis, Lobosceliana loboscelis, Cyathosternum prehensile, Heteropternis thoracica, Pseudothericles jallae, Enallagma cyathigerum, Pseudagrion hageni, Lestinogomphus angustus, Rhyothemis semihyalina and Orthetrum brachiale
- Ecdysozoa                                                
- Protostomia                                                
See also Burtoa nilotica
- Nephrozoa                                                     
- Bilateralia                                                            
- Eumetazoa                                                            
- Animalia                                                                 
- Eukaryota                                                                



And now that really is all, folks!




Note: 

Other African Nephila not discussed within the text: 

N. comorana - not found on the mainland.
N. constricta - seems to have hairless legs, a la N. inaurata.
N. komaci - described as having a long, broad abdomen, a very distinctive colour pattern and a disjunct range.
N. pilipes  - in Africa, found only in Madagascar and associated islands.
N. sumptuosa - has a long, broad abdomen, unlike those seen in adults in and around Lusaka.
N. turneri - although range unclear, very distinctively coloured.


Although not particularly user-friendly, and there are definitely a few images that have been incorrectly assigned, the South African National Survey of Arachnids Virtual Museum is probably the most ambitious resource currently freely available for the full diversity of African Arachnids. It's worth noting that, given the shortage of information on this group, that's not as prestigious as it sounds.