Hemerobius lutescens

One of our commonest species of brown lacewing that has been recorded between February and November. My own records show two peaks, a smaller one in spring (early May to early June) and a larger one between late July and mid September, with stragglers from late March to mid October.

The presence of a recurrent humeral vein and 3-4 branches to the radial vein helps separate Hemerobius from Psectra and Micromus, and the position of veing RMCV (inside the fork of vein M) helps to rule out Wesmaelius. However, note that vein RMCV is often unpigmented in Hemerobius so you may need to look really carefully for this and it might not show up in photos (as shown in the photos below, it may be easier to see when the wing is backlit).

female Hemerobius lutescens showing base of forewing (lit from above in first photo, backlit in second photo), County School Station, North Elmham (Norfolk, UK), 23rd March 2022

Although on average they have a weaker pattern of dark markings on the wings, Hemerobius lutescens can look extremely similar to Hemerobius humulinus. See the FSC AIDGAP guide (Plant, 1997) for details of how to separate lutescens from humulinus by the tip of their abdomens. The female abdomen is shown below - note that the last segment is produced much further than on humulinus. This can be hard to see on live specimens but is an easy character to use on freshly dead specimens. Beware dried-out dead specimens where the projecting segment can retract into the abdomen making it difficult to determine - the individual shown here had only been dead for a day or two and was already too shrivelled to see clearly - I got round this by partially clearing the abdomen in potassium hydroxide solution, but if you don't have suitable dissection chemicals available then I shouldn't be surprised if soaking it in water would suffice.

same female Hemerobius lutescens showing partially-cleared tip of abdomen, County School Station, North Elmham (Norfolk, UK), 23rd March 2022

female Hemerobius lutescens, North Elmham Cathedral Meadows (Norfolk, UK), 25th May 2019

female and male Hemerobius lutescens, Hell Pit near Longham (Norfolk, UK), 15th May 2016

female Hemerobius lutescens, North Elmham (Norfolk, UK), 10th August 2019

female Hemerobius lutescens, North Elmham (Norfolk, UK), 11th August 2018

female and male Hemerobius lutescens, North Elmham (Norfolk, UK), 18th September 2018

female Hemerobius lutescens, North Elmham (Norfolk, UK), 20th August 2020

female Hemerobius lutescens, North Elmham (Norfolk, UK), 20th September 2018

female Hemerobius lutescens, North Elmham (Norfolk, UK), 22nd August 2016

female Hemerobius lutescens, North Elmham (Norfolk, UK), 31st August 2018

male Hemerobius lutescens, North Elmham Cathedral Meadows (Norfolk, UK), 19th May 2018

male Hemerobius lutescens, North Elmham Cathedral Meadows (Norfolk, UK), 21st May 2019

male Hemerobius lutescens, North Elmham (Norfolk, UK), 1st September 2018

2x male Hemerobius lutescens, North Elmham (Norfolk, UK), 14th August 2020

male Hemerobius lutescens, North Elmham (Norfolk, UK), 15th August 2020

male Hemerobius lutescens, North Elmham (Norfolk, UK), 18th August 2018

male Hemerobius lutescens, North Elmham (Norfolk, UK), 18th September 2020

2x male Hemerobius lutescens, North Elmham (Norfolk, UK), 19th August 2020

male Hemerobius lutescens, North Elmham (Norfolk, UK), 20th September 2019

male Hemerobius lutescens, North Elmham (Norfolk, UK), 22nd August 2018

male Hemerobius lutescens, North Elmham (Norfolk, UK), 22nd September 2020

male Hemerobius lutescens, North Elmham (Norfolk, UK), 23rd August 2016

male Hemerobius lutescens, North Elmham (Norfolk, UK), 25th May 2019

male Hemerobius lutescens, North Elmham (Norfolk, UK), 26th August 2018

male Hemerobius lutescens, North Elmham (Norfolk, UK), 31st July 2020

male Hemerobius lutescens, Row Heath near West Runton (Norfolk, UK), 27th May 2017

There are no good references covering lacewing larvae identification and the identity of this one is unknown. It may possibly be this species whose larvae apparently look similar.

possible Hemerobius lutescens larva, North Elmham Cathedral Meadows (Norfolk, UK), 12th October 2019