Orius laevigatus

Most of the Orius bugs I've found have been females which can be very tricky to identify. This one is apparently a common species but is particularly difficult to tell from Orius niger which is also common (more common I think).

This male was swept from Yarrow (though other plants were also present) and its identification was confirmed by the double flagellum on the paramere. Most species of Orius were eliminated by the long hairs in each corner of the pronotum but this feature is shared by Orius niger. The mid tibia are supposed to be darker on niger, but on this specimen they could hardly be described as pale brown (as described for laevigatus, in contrast to dark brown or black for niger). Orius niger can be much darker overall, but more importantly males have a single flagellum on the paramere.

male Orius laevigatus showing pronotum, mid tibia and paramere, North Elmham Cathedral Meadows (Norfolk, UK), 9th September 2021

This was swept from Hemp Agrimony. I could only see a long hair at one corner of the pronotum but although they should have one at every corner (but they break off) I think just one counts. However it was a little way up the side from the very corner so I did wonder if it was the correct hair until I found Alan Cann's helpfully annotated images at NatureSpot which clearly point to the hair in the same position. That much puts it into the laevigatus or niger camp.

When I processed this I possibly made an error which meant I identified it confidently but a little carelessly as laevigatus. A little later I processed three niger specimens and realised I'd possibly made a mistake with this one, deciding that I couldn't be certain about it any more - but at this point I forgot about the relevance of the mid tibia colour. Then when I remembered the leg colour feature I was initially put off from going back to calling this one laevigatus as the two photos showing the mid tibia differ (it looks darker in the first but relatively pale in the second). By this time I had discarded all four specimens, but I still had them in my discard pot. Sifting through this I managed to find all four and work out which was which. Unfortunately this one had lost its mid legs completely so I wasn't able to firm up how pale they'd been, but compared to the other three this specimen was slightly larger which probably favours laevigatus and generally paler (noticeably on the clavus). In particular the front femora (still attached) were obviously paler than on the niger, and looking at quite a few photos of both species online this appears to be at least a good pointer towards laevigatus. Taking all things together I think my original ID was correct and I was too quick to doubt myself when I later examined some niger.

female Orius laevigatus showing pronotum, Rush Meadows NWT (Norfolk, UK), 15th July 2025