Tuesday 20 August 2013

Stictogryllacris cf punctata (von Wattenwyl, 1888)

Because there's going to be quite a long discussion of its ongoing identity crisis, we'll
start with the picture...

Stictogryllacris punctata, Chongwe, Lusaka, Zambia

 This is a leaf rolling cricket from Chongwe, Lusaka Province, Zambia, and I think it's Stictogryllacris punctata. But I'm not certain. Here's another picture before we get started on why I only think it's Stictogryllacris punctata.


So, let's start with what is known:

Eukaryota
  Animalia
    Eumetazoa
      Bilateralia
        Nephrozoa
          Protostomia
            Ecdysozoa
              Arthropoda
                Hexapoda
                  Insecta
                    Dicondylia
                      Pterygota
                        Polyneoptera
                          Anartioptera
                            Polyorthoptera
                              Orthopterida
                                Panorthoptera
                                  Orthoptera
                                    Ensifera
                                      Stenopalmatoidea
                                        Gryllacrididae
                                          Gryllacridinae
                                  
Now here is were it gets iffy. Based on ranges identified and visual comparisons of specimens pictured on Orthoptera species file, it could potentially be either of two unpictured Niphetogryllacris - N. meruensis and N. kilimandjarica, both of which are described as fully winged... based on 'Vorderschiene' being fore tibia, N. kilimanjica is ruled out by having 5 paired spines.
N. meruensis is also ruled out by virtue of it being described as 'Kopf und Pronotum ganz ohne dunkle Zeichnungen', which I believe means that the head and pronotum lack dark markings.Which - accompanied by the distinct ranges of other Niphetogryllacris, rules out that Genus.

The other promising genus is Stictogryllacris, which has a promising range, and 9 known species. Of these:

S. fülleborni lacks markings to its head and pronotum, although it is recorded from neighbouring Tanzania - ruled out.

S. laetitia is widespread, but all subspecies, again, seem to lack any distinct markings on the head and pronotum - ruled out.
S. lyrata, though only pictured as faded specimens, seems to have the colouring of the spines in common, but lacks the ornate patterns to the frons - ruled out.
S. nana is only recorded from Natal, although unpictured and therefore troubling. Probably can be eliminated.
S. pallidus is far more northerly in its distribution - tentatively ruled out.
S. picteti, like S. nana,, is entirely unpictured, and can only be tentatively ruled out by its non-overlapping range (French Congo).
S. pygmaea is recorded only from islands in the Gulf of Guinea. Ruled out.


This leaves two species - Stictogryllacris quadripunctata and S. punctataThe names of both are quite convincing, and both are - and were originally - described by Brunner von Wattenwyl in what seems to be Latin in the Verhandlungen der Kaiserlich-Koniglichen Zoologisch-Botanischen Gesellschaft in Wien (1888). Did I mention Latin?

I never learnt Latin, and as great as Google translate is, it seems to lack any notion of technical terms. So this translation is liable to be iffy.

Both species are long-winged, with S. punctata's wings described as 'Elytra ampla, cum alis pallida, femore postico sub duplo longiora', and S. quadripunctata as 'Elytra femore postico duplo multo longiora, acuminata', which I'm reasonably confident means that S. quadripunctata has pointed forewings more than twice the length of its rear femora, while S. punctata has long, pale forewings that are less than twice the length of the femora.Which - unless the angle of the photograph makes the femur look shorter (or I haven't correctly distinguished between the fore and hind wings...), would tentatively indicate that this was S. quadripunctata (my limited knowledge of the various grasshoppers and crickets indicates that, provided wings are present at all, wing length is an inconsistent and often climate-dependant variable).

But - and this bit I am certain of my translation of - S. quadripunctata is described as having 3 spines on the inner margin of the hind femora, and five on the outer - the photographed species has 2 and six, respectively. Annoyingly, no mention is made of the number of spines on S. punctata's legs, so as much as this seems to rule out one species, it doesn't confirm the other. Irksome.

Other points - an oblique line from side-to-side of the back of the head, and a pronotum decorated with points and lines, and the appropriate (Angola) distribution, support S. punctata, hence the title, but until I write to someone who knows better and say "Oi, is this Stictogryllacris punctata, or Stictogryllacris at all?", this remains very tentative identification...

Probably Stictogryllacris probably punctata
probably (von Wattenwyl, 1888)

Spotted Leaf-Rolling Cricket.






NB - other Afrotropical Gryllacrine genera ruled out are: Afrogryllacris (seems to be entirely west african, and rather sturdier), Afropacra (one species, with distinctive colour patterns), Afroneanias (one species, the female shown bore some resemblance, including the two-six pattern of spines on the hind femora, but was only recorded from Kenya), Ametroides (seems to be entirely wingless), Atychogryllacris (stockier, and apparently limited to north-western parts of central africa), Barombogryllacris (more northerly, structurally distinct), Diaphanogryllacris (the only African species, D. postica, is distinctively marked and, within Africa, only known from Madagascar), Echidnogryllacris (only one species, which again is Malagasy and disctinctive), Glomerinus (which, although having an appropriate range, seems to consist of chunky, pale-spined and wingless species), Gryllacris (primarily non-African, but one species occurring in Madagascar, another in Congo - species pictured show little resemblance to current), Hadrogryllacris  (with one dissimilar african species from Ghana), Pissodogryllacris (Madagascan (and Comorosan?) distribution, long-spined, dark-bodied species pictured bear little resemblance), Pseuderemus (monotypic and malagasy).

PS - I sincerely apologise for the former unnecessary apostrophe, and would like to assure any readers that I do not intentionally abuse punctuation. My mind was preoccupied, which is how I came to wrote a plural as a contraction...

No comments:

Post a Comment