Wednesday, February 22, 2023

Hobby "Ergaula pilosa" are NOT E.pilosa...

Welcome once again, to today's installment of "Old Hobby Stock Roach IDs Were Made Waaaay Too Hastily and We're All Paying For it Now"! 🙃😂

Thanks to my friend Martin, who originally brought this to my attention as we were discussing this genus, we've both done a little digging (Martin more than me), and it would seem there are significant differences in size and pronotum shape between hobby stock "E.pilosa" and actual E.pilosa...

Ergaula pilosa is a species that's restricted to Indonesia and Malaysia, they have very deep pits/indentations on the anterior margins of their pronotums (even more noticeable than on E.capucina), with adult males maxing out at around 30mm, females 26 mm or so, (so about E.capucina sized). They are generally referred to in literature as being light or dark brown in color, not black like the hobby stock "pilosa".

Non-type female from Sabah ©CSF
Non-type female from Selangor ©CSF
Non-type male from Selangor ©CSF
Holotype female of M.silphoides, a synonym of E.pilosa ©L. Chopard
This is in contrast to the old hobby stock of Ergaula "pilosa", which only have very shallow pits on the anterior margins, more shallow than on E.capucina. They're larger too, males maxing out at 35mm (though often coming out more capucina sized), with females maxing out at 37mm. They're also darker, black or very dark brown (though in well lit pictures, like the ones down below, their velvety hairs often make them appear a lighter brown than they do in real life). The only locality data that has been recorded for this old line is "Borneo", which does at least narrow the (described) options to E.funebris, and E.pilosa.

Now, the hobby stock is obviously not the latter, so might they be funebris? Perhaps, unfortunately only a single male of E.funebris has ever been described in literature, no females. The description for the holotype male much more closely matches the morphology for the hobby stock "pilosa", with only shallow pits on the pronotum, a much darker brown/black coloration, rather than the lighter brown of true E.pilosa. The holotype funebris male lacks any light spots on it's tegmina completely, which is a common trait of the hobby stock "pilosa" males (though some do come out with spotting as well, it's a variable pattern).
However, the Holotype funebris is rather small, only 26mm, which puts it at the same general size as capucina males. Granted, some hobby stock "pilosa" males come out basically the same size as capucina as well, their size seems to be a lot more variable than that of the females, who even in crowded conditions seldom stunt much. It would be really helpful if an adult female funebris had been described as well, to compare in size and morphology to the females of the hobby stock "pilosa".

Anyways, here are some pictures of hobby stock "pilosa", courtesy of Paul Sutton of Paul's Pills, who kindly took these pictures for this very blog post:

Adult female hobby stock "pilosa". Notice the SUPER shallow pronotum pits. 

Adult female hobby stock "pilosa". Again, note the shallow, almost absent pronotum pits.

The difference between these and true pilosa in terms of pronotum morphology is rather noticeable IMO (and supposedly the coloration is noticeably different as well).
So overall, it seems clear to me that the old "pilosa" stock in culture is NOT E.pilosa. They might be E.funebris, and this does seem the most probable ID, however with information on the females of that species being nonexistent, I can't rule out that the hobby stock "pilosa" might not be funebris, but in fact an undescribed species.
So, I personally propose that the old hobby stock of Ergaula "pilosa" be relabeled to Ergaula sp. "Borneo", or if you're more confident than I am regarding their similarities to funebrisErgaula cf. funebris "Borneo"

There is hope for actual E.pilosa existing in culture though. In the Russian hobby, they have a stock of Ergaula collected recently from Kinabatagan, Malaysia, which has pronotum structure much more like that of true E.pilosa (and the range fits too). Unfortunately more details about them and their body length are scant, and these aren't in culture anywhere else in the world besides Russia ATM. But hopefully they'll spread around in the hobby worldwide, eventually...

Ergaula cf. pilosa "Kinabatagan, Malaysia" ©Reptomania
Anyways, that's gonna be it for this post, thanks for reading, hope everyone enjoyed, stay safe, and I'll see you all next time! 😉

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