White band on Gatekeeper

[htcdude]

I was wondering if anyone could figure out what the white bar is on this Gatekeeper? I've not seen anything like it before, maybe human interference??

Thanks,

Nige

[Padfield]

It certainly looks like marking for some experiment, though I've never seen that form before. Certainly not natural!

Guy

[David M]

I can't figure out why such a marker would need to be used. Looks pretty cumbersome for the butterfly.

[MikeOxon]

Could this be part of a tag for tracking the movement of the butterfly by harmonic radar? See, for example, http://phys.org/news3623.html It is certainly not just a paint mark as it does not conform to the surface of the abdomen.

A long time ago, I wrote the original UK paper on harmonic radar [Flemming, M. A., Mulllins, F. H., and Watson, A.: 'Harmonic Radar Detection Systems', Radar-77. IEE Conference, London, pp. 552–555, 25–28 October, 1977]. The insect just needs to carry a tiny semiconductor diode, which acts to double the frequency of a radar signal that is used to track it. The frequency-doubled signal is easily distinguished from the natural radar reflections from foliage, the ground, etc.

Mike