Sunday, 12 July 2015

Two interesting female gomphids from the Nam Bung area.

Saturday July 11 I caught a small female gomphid near Nam Bung. I had never seen it before and studying it in hand revealed a very neat "horn" on the occipital ridge. Now, female gomphids very often have horns on their heads, but the shape of this one, like the tail of a diving whale ("fluking") is extra-ordinary. This pointed me to the genus Sinogomphus. This is, at least for me, really exciting. Last year in early May I had caught Sinogomphus leptocercus in the same general area, but thereafter the species remained elusive, in spite of several searches. I have no description of the female of this species, so I have to exercise some caution here. Nevertheless it is not very likely at all that there is another Sinogomphus species in the area (there are no Sinogomphus species known from Vietnam). So this should be the female of S. leptocercus!

Another female I caught is Leptogomphus divaricatus. This is not at all a rare species, being probably the commonest species in the north of the genus after L. perforatus. But I have not often seen the female and failed so far to take pictures of its distinctive divaricate horns. Glad to put that right!

First the female of Leptogomphus divaricatus, typical as Leptogomphids go.

But they can often be told apart by the horns on the occipital ridge. L. divaricatus has two that bend outward in opposite directions.

But look at this! Is this remarkable or what? Female Sinogomphus leptocercus. As if mommy bound her baby's hair together into a little palm tree.

Dorsal pattern fits several Sinogomphus species and of course also S. leptocercus.

The whole specimen in lateral view. The lateral pattern of the thorax is a little different from the male (see that entry), but otherwise patterning is similar.

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