Trioza remota

This seems to be one of the commonest psyllids, or at least one of the ones I encounter most often.

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 urticae: 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.

The proportions of the forewings, and the proportions of cell Cu₁ are important for separating this species from similar species. I don't always measure them as I have done here - judging from the diagrams in the key I think the differences should be reasonably easy to tell by eye. This one was beaten from pine, though the species is normally associated with oak.

female Trioza remota showing forewing (including close-up of cell Cu₁), genal cones and terminalia, Bintree Wood (Norfolk, UK), 31st March 2021

There is quite a lot of variation in body colour. This one is one of the paler ones I've come across, with the greenest abdomen.

female Trioza remota showing forewing, North Elmham (Norfolk, UK), 23rd October 2022

Here is a much darker one.

female Trioza remota, North Elmham (Norfolk, UK), 18th December 2022

The terminalia aren't as important for this species as they are for some, but it can help to confirm if you are not quite sure. It may be easier to view after macerating in potassium hydroxide solution. In this case I was put off by the clear yellowy-brown colour wash to the wings which some sources say Trioza remota shouldn't have, but it seems this isn't consistent.

female Trioza remota showing forewing and terminalia, North Elmham (Norfolk, UK), 10th January 2019

female Trioza remota, North Elmham (Norfolk, UK), 2nd November 2022

The extent of surface spinules on the forewings seems to vary - not all are as extensively covered as this one.

female Trioza remota showing forewing (including close-ups to show surface spinules) and terminalia, North Elmham (Norfolk, UK), 23rd October 2021

The surface spinules were hard to see under 63x magnification on this one, though they were just visible. This one was beaten from a small conifer (possibly Yew).

male Trioza remota showing forewing and genitalia, North Elmham railway (Norfolk, UK), 4th January 2024

As with female terminalia, male genitalia are not always necessary to identify this species but can help to double-check. It is not necessary to dissect the insect to examine these, just a side-profile view of the abdomen is normally sufficient.

male Trioza remota showing forewing and genitalia, North Elmham (Norfolk, UK), 28th February 2022

female Trioza remota, North Elmham Cathedral Meadows (Norfolk, UK), 27th October 2019

female Trioza remota, North Elmham (Norfolk, UK), 25th October 2019

male Trioza remota, North Elmham Cathedral Meadows (Norfolk, UK), 27th October 2019

Sometimes on dried specimens it can be difficult to view the genitalia, and in that case it helps to macerate the abdomen in potassium hydroxide solution.

male Trioza remota showing forewing (including close-up showing surface spinules)and genitalia (before and after clearing in potassium hydroxide solution), St Mary's churchyard, North Elmham (Norfolk, UK), 16th October 2021

male Trioza remota, North Elmham (Norfolk, UK), 18th December 2022

male Trioza remota, North Elmham (Norfolk, UK) showing forewing and genitalia, 23rd October 2022

male Trioza remota, North Elmham (Norfolk, UK) showing wings (including close-up showing forewing surface spinules) and genitalia (before and after clearing in potassium hydroxide solution), 27th October 2020

male Trioza remota, North Elmham (Norfolk, UK), 29th October 2022

male Trioza remota showing forewing and genitalia, North Elmham (Norfolk, UK), 6th November 2022

The strangely flat nymphs can sometimes be found in hollows on oak leaves. This one was photographed using different cameras (one with flash, the other through the microscope) and each has brought out different characters. This was before I had found the RES key to nymphs and unsure what it was I posted a photo on Twitter. Andy Musgrove suggested the ID and James Heal confirmed.

Trioza remota nymph, North Elmham Cathedral Meadows, (Norfolk, UK), 24th August 2020

male & female Trioza remota in copulation, North Elmham Cathedral Meadows (Norfolk, UK), 22nd May 2019

female Trioza remota showing forewing and terminalia, North Elmham (Norfolk, UK), 10th October 2023

female Trioza remota showing forewing and terminalia, North Elmham (Norfolk, UK), 18th October 2023

male Trioza remota showing forewing and genitalia, North Elmham (Norfolk, UK), 18th October 2023

2x female Trioza remota, North Elmham (Norfolk, UK), 20th October 2023

female Trioza remota showing forewing and terminalia, North Elmham (Norfolk, UK), 20th November 2023

The next two were beaten from the lower branches of a pine tree.

female Trioza remota showing forewing, Ringmere (Norfolk, UK), 7th February 2024

male Trioza remota showing terminalia, Ringmere (Norfolk, UK), 7th February 2024

Finding myself next to a laurel and recalling that there was a psyllid I wanted to see on Laurel, I checked the leaves of the tree and very quickly found this psyllid. When keying it out I realised that the psyllid I was thinking of was on Bay Laurel, completely unrelated to the Cherry Laurel I found it on. Oh well, I just have to find a proper Bay tree now...

female Trioza remota showing forewing, Beetley Meadow (Norfolk, UK), 8th April 2024