Tuesday, 9 September 2014

A. gigantica. Another Anotogaster!

Sunday September 7 I visited the Yen Bai area and checking a small stream running of the hills alongside QL32 I noticed a large dragonfly cruising. Large, but not extremely large. Nevertheless, when it passed once more it was clearly a Goldenring. It flew up the hillside and hung up in some shrubs. I could take a few record shots and then clambered up the hill until close to it and as this was a lucky day, I could net it. In hand it was immediately obvious from the small size and the yellow mandible bases that this was neither A. sakaii (larger and missing yellow bases), nor A. klossi (larger, although with yellow mandible bases, but different appendages). Indeed, checking the appendages, these were clearly different from what I had seen before, with a very clear large ventral tooth at over one third of the superior appendage, plus another basal one. The top of the frons was black, so later I could rule out A. kuchenbeiseri (which has yellow dorsum to the frons) and A. gregoryi, which has different teeth to the superior appendage. Remains A. gigantica. What is in a name, for a smaller species! But indeed, gigantica is a smaller Anotogaster, if still close to 9 cm. The appendages are rather distinctive, although apparently the specimens from Sapa miss the clear yellow bases to the mandibles. Although the IUCN list only mentions the species from a few old records from Yanmar, Karube (2012) illustrated it as one of 5 species of Anotogaster occurring in Vietnam. It was until now only known from Sapa.
The beautiful Anotogaster up in the shrub. Immediately the very yellow appearance is obvious
And in hand. Note the large yellow lateral markings on the thorax, and broad yellow rings on the abdomen down to S9. The yellow bases to the mandibles are also visible.

Although difficult to capture with my microscopic camera, this shot in the field of the appendages shows the clear ventral tooth almost in the middle of the superior appendage and directed anteriorly, plus a smaller but obvious basal ventral tooth. The epiproct is clearly getting thicker towards its apex and reaches to two thirds of the superiors.
Just short of 9 cm, a full cm smaller than A. klossi and A. sakaii, which is just as well. Those are chunky bulky things, this is a slender beautiful insect.

Typical diverging superiors

Another shot, with the microscopic camera, of the ventral tooth.

Ventral view of appendages 

And lateral view of S1-2. Note the different lamina compared to A. klossi (see that post).

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