Trioza urticae
This is meant to be a very common species but I can't help wondering if 2021 was a good year, or at least a better year than the previous few, as I had multiple records from each of four sites (including my garden) despite never having recorded it before. The species is mainly found on nettles but is often found on other plants, especially conifers in winter - I've found it on Yew, pines, Spindle, Garlic Mustard and Dog's Mercury (as well as Common Nettle).
The genus Trioza can be separated from all other jumping plant lice that I've ever encountered by wing venation - veins Cu1 and M arising from a common origin in vein R. I'm not sure if any of the genera that I've not seen might share this character - the RES key differentiates the others be either having flattened antennae, no genal cones or brown-patterned wings.
The only Trioza species that I encountered regularly are this one and remota: urticae differs from remota in having vein R long, extending past the junction where vein M forks, but this is not diagnostic as in either case it is shared by a number of other Trioza species. Refer to the key for other characters but most are illiustrated below.
One such character is the widely-divergent triangular genal cones shown below.
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female Trioza urticae showing genal cones, terminalia and forewings, Wendling Beck Environment Project (Norfolk, UK), 13th November 2021
Another character is that the surface spinules on the forewing are largely confined to the base of Cu2. Note there seems to be quite a bit of variation in the colour of the forewings - pretty much clear in the individual above and quite obviously brown in this one.
, Elmham Park, 25-Mar-22 (A) (1).jpg)
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, Elmham Park, 25-Mar-22 (A) (3) (1).jpg)
, Elmham Park, 25-Mar-22 (A) (4) (1).jpg)
, Elmham Park, 25-Mar-22 (A) (5) (1).jpg)
female Trioza urticae showing wings (including close-up of spinules in region of Cu2) and terminalia, Elmham Park, North Elmham (Norfolk, UK), 25th March 2022
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female Trioza urticae showing forewing and terminalia, St Mary's Churchyard, North Elmham (Norfolk, UK), 7th December 2021
, Dillington Carr, 15-Nov-21 (A) (3).jpg)
, Dillington Carr, 15-Nov-21 (A) (1).jpg)
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female Trioza urticae, Wendling Beck Environment Project (Norfolk, UK), 15th November 2021
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female Trioza urticae, North Elmham (Norfolk, UK), 12th November 2021
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female Trioza urticae, North Elmham (Norfolk, UK), 19th October 2021
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male Trioza urticae, Wendling Beck Environment Project (Norfolk, UK), 11th April 2022
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male Trioza urticae, Wendling Beck Environment Project (Norfolk, UK), 15th November 2021
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Trioza urticae, North Elmham Cathedral Meadows (Norfolk, UK), 9th July 2021
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Trioza urticae, Wendling Beck Environment Project (Norfolk, UK), 29th January 2022
Trioza urticae, St Mary's churchyard, North Elmham (Norfolk, UK), 6th December 2021
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Trioza urticae, Elmham Park, North Elmham (Norfolk, UK), 7th January 2022