jccurd's picture

Cooperative Chaser

Observed: 12th May 2011 By: jccurdjccurd’s reputation in Invertebratesjccurd’s reputation in Invertebratesjccurd’s reputation in Invertebratesjccurd’s reputation in Invertebrates
IMG_9558_Four-spotted_Chaser
Description:

I know, I've done it before, but this posed so nicely I couldn't help myself. Besides, it is my first decent shot of one from this location. Thanks to my spotter for finding it. :))
After a little more investigation, I think this specimen is what's known as form praenubila, with dark smudges behind the pterostigma.

Identifications
Species interactions

No interactions present.

Comments

Peter Allen's picture

I know!

I know how the shutter finger gets twitchy! Thank goodness we've moved on from film....

Hampshire Dragonfly recorder
Hampshire & IOW Wildlfe Trust

jccurd's picture

Out of curiosity, Peter,

... as the Hampshire Dragonfly recorder, I'm wondering if you know (of) Doug Overton (newforestdragonflies.com) and Paul Ritchie (hampshiredragonflies.co.uk)? I'd guess you must do.

John

jccurd's picture

Is this f. praenubila?

Comparing this to my only other good shot of L. quadrimaculata, this one seems to show more extensive wing node markings and a dark smudge behind the pterostigma which might indicate that this specimen is form praenubila.

RoyW's picture

praenubilia

This could cetainly be described as the praenubila form, although it is nowhere near as extensively marked as they can be.

As I was saying on another website recently, I'm not sure how extensive the markings behind the node and pterostigma have to be before the praenubila name is generally applied - there is a continual graduation from the 'normal' form (with no addition black markings) through to individuals with almost the entire wing tip black, and large 'splodges' at the nodes (eg: http://www.pbase.com/glazemaker/image/45275241 ).

jccurd's picture

Thanks, Roy

Your link example certainly has very extensive wing node and tip markings ,doesn't it? Mine, as you say, is much less extensively marked. In fact, it's really only the left wing, that is against a bland background, that makes the wing tip markings visible. It's very slight. The thing I noticed first was slightly larger wing node spots.

I presume the reason that this praenubila isn't regarded as a separate subspecies is genetic? We are just seeing individual variations, rather like that of the Azure Damselfly I had recently whose S2 looked very like a Variable. (Practice checking the pronotum, eh?)

John