Thursday, 18 July 2019

Xanthogramma stackelbergi

Although Paul Tabor has recorded this species twice in the valley before, this is my first Xanthogramma stackelbergi, which was only added to the British list as recently as 2012. It has a number of identification differences from the very similar Xanthogramma pedissequum. Of the 6 Glamorgan records 3 have been in the valley.




"This species closely resembles X. pedissequum and was added to the British list in 2012 by Alan Stubbs . Females have the black stripe on the frons very narrow and often petering out where it meets the lunule. The yellow spots on tergite 2 are squarer than in pedissequum and those on tergites 3 and 4 more oblique. The sides of the thorax below the level of the wingbases seem to always have four/five yellow spots, with two always located near the halteres (often missing in pedissequum). This is one of the best field characters Further differences exist in the wings and underside of the abdomen. The dark costal patch of stackelbergi does not usually extend below vein R3+4 in contrast to typical pedissequum. Viewed from the underside, both sexes have the narrow membranous area between the sternites and tergites mainly yellow except for a dark patch coinciding with the posterior transverse stripe of sternite 2, and this creates a dark band that is less than half of the length of this sternite i.e. much less extensively darkened than pedissequum. X. stackelbergi seems to be widespread but localised in southern Britain and to show a stronger attachment to woodland edges, rides and clearings than pedissequum."

Above quotes taken from Steven Falk's flickr page :-

https://www.flickr.com/photos/63075200@N07/sets/72157632548622900/

Below are some photos of typical Xanthogramma pedissequum.





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