Harvestman ID

[Geoff F]

Right then, let's have another think about Serendipity's little friend and start with the easy stuff.

Rilaena triangularis is generally a spring or summer harvestman. Phalangium opilio is a late summer and autumn specimen. But this is a generality as a few late R. triangularis can be found well into the autumn.

P. opilio males have very distinctive chelicerae and pedipalps which this individual lacks and the females usually have a dark coloured saddle but sometimes this can be very pale. Legs are quite long; 2nd leg 30 to 48 mm.

R. triangularis has a larger ocularium with a paler central area. A dark line often runs forward from the ocularium and ends with a tubercle on it's 'nose' which can be mistaken for a trident which is present on a number of other species. But this is hidden in our specimen, as are a number of other clues.

This species also normally has some form of dark coloured saddle but this can be absent in males. Legs are more moderate in length with the second leg around 28 to 38 mm, but this can slightly overlap with the size of a small P. opilio.

There appears to be some 'spikiness' on the lower side of the pedipalp femur which does make me lean towards R. triangularis .

So putting all this together; I think I would probably now go more for R. triangularis possibly a male. But I would be more convinced of this if it was a spring sighting.

[serendipity]

Erm! it was the start of June Geoff! In a cedar wood!
Why not try Jason its all part of the fun. And thanks to all for the input. the learning curve is what its all about.

[Geoff F]

Early June is one more vote for R. triangularis.

That doesn't rule out any of the other options but it is a touch early for them.

ps. For anybody interested in learning more about harvestmen; here is Gordon's identification guide http://www.supermacro.net/phpBB3/vie...37;E2%80%A6#p2

And for anybody who is keen enough to spend a little bit of money, I would recommend Harvestmen by P. D. Hillyard. I purchased my copy from the Field Studies Council.

[Action_Man]

One of the main characteristics of Rilaena triangularis, is the eye turret size in relation to the body, as you can see in this specimen, they are quite large, quite unique to Rilaena triangularis, they are also surrounded by quite large spines.

So just looking at the eyes alone, you could say its a typical Rilaena triangularis.