Chrysoperla lucasina

Since this species was first described it has been lumped with Chrysoperla carnea, split again, lumped again and split yet again. The last decision to reinstate it as a distinct species was primarily based on analysis of songs which are unfortunately not possible to hear without specialist equipment under laboratory conditions. However Henry, Brooks, Johnson & Duelli (1996)¹ found consistent differences in appearance between the individuals with lucasina song type and individuals with other song types. The most important character for individuals that have not turned brown in winter (ruling out lucasina) apears to be the colour of the membrane between at least the second tergite and the second sternite - brown on lucasina and green on carnea and pallida.

There are now three Chrysoperla species in the UK - see my page for Chrysoperla carnea for details of how to separate these from other genera. Plant (1997) provides the following characteristics for lucasina:

• Membrane between tergites 1 & 2 and sternites 1 & 2 brown (but the key allows for an identification of lucasina if this is not clearly the case)
• Tornal region of forewing straightened making wing tip appear slightly pointed
• Insect remains green throughout winter, not becoming brown
• Hairs on leading edge of costa shorter than on carnea

Note that to accurately judge the shape of the wing you need to ensure the wing is flat. I now remove the forewings and flatten them under a microscope slide weighed down on either side. Even then I have often found it very difficult to judge the wing shape on Chrysoperla with some individuals being intermediate or at least not clearly one shape or the other. However on the basis of Plant I identified a small number of individuals with more clearly pointed wings as lucasina, even though the membrane between the tergites and sternites was wholly green. It wasn't until 2025 that I managed to locate the paper that separated lucasina on the basis of song types, and discovered that the research behind this paper found that every single male in their sample that sung like lucasina (and if I understand it correctly also the females that responded to lucasina song) had a dark membrane (at least on segment 2), which suggests that it is at best very unusual for lucasina to have a wholly green membrane. Other earlier authors had found wing shape and the length of costal hairs to be unreliable. This casts significant doubt on my previous identifications - and indeed any identification of lucasina lacking a dark membrane between at least some of the basal abdominal segments. I am therefore currently treating any record of lucasina (including my own) as unproven or at best provisional if it did not have a dark membrane (or if this is not recorded) with the possible exception of individuals that have clear evidence of both unambiguously pointed wings and comfortably short (measured) costal hairs (and ideally also mostly pale abdominal hairs, although this seems to be even more variable).

When submitting records of Chrysoperla lucasina please indicate what characters you used to identify it, preferably with supporting photos.

Also in 2025, for the first time in the several years that I have been examining Chrysoperla specimens, I have found several individuals that do have a dark membrane between at least the second and third tergites and sternites. Although some of these have rounded wings, many (but not all) have quite short, or clearly short, costal hairs. Given that I can find no reference in any of the literature that clearly indicates either carnea or pallida (or indeed any of the other European lookalikes) can have dark membranes, I am identifying all of these as lucasina - and concluding that 2025 is an exceptionally good year for lucasina, at least by recent standards.

¹ Henry, C. S., Brooks, S. J., Johnson, J. B. & Duelli, P. (1996) Chrysoperla lucasina (Lacroix): a distinct species of green lacewing confirmed by acoustical analysis (Neuroptera: Chrysopidae). Systematic Entomology 21: 205-218. This paper can be downloaded here.

This individual showed a dark line through the abdominal membrane between half way down segment one and segment three. The wing shape would not have caused me to suspect lucasina had it not had a dark membrane but the costal hairs were short.

female Chrysoperla lucasina showing abdominal membrane, side of head. forewings and costal hair length, Wendling Beck Environment Project (Norfolk, UK), 4th July 2025

Note that I've been measuring the costal hairs by measuring the actual length of individual hairs at around the middle of the costa. Some references that refer to the length of costal hairs do not provide an actual length or range of lengths for each species, nor any indication of how they might be measured, simply stating that they're shorter on lucasina and longer on carnea. Henry, Brooks, Johnson & Duelli (1996) does provide a figure but I think this must be a mistake - it says, "the setae on the costal margin of the fore-wing were usually short (<1.0 mm)." No matter how you measure them I cannot conceive that they could ever be anything like as long as 1.0 mm on any species of Chrysoperla - the longest I've measured on Chrysoperla carnea is only a little over 0.2mm. One earlier reference that I've only recently found does detail how they measured the costal hairs, and it's quite different from how I've measured them. They're actually not measuring the hairs at all, but the width of the fringe of hairs (which differs from the length of individual hairs because the hairs are slanting). They measure the width of the fringe perpendicular to the costal vein opposite the second costal cross-vein. It may be that subsequent authors have used the same approach in which case any figures quoted would not match my own measurements (but this certainly doesn't explain the anomalous figure of 1.0mm given in Henry et al.). On this one, like the one above, the length of the hairs (the way I measure them) was shorter than most carnea.

female Chrysoperla lucasina showing abdominal membrane, tip of abdomen, forewings and costal hair length, North Elmham (Norfolk, UK), 18th August 2025

There weren't many costal hairs left to measure on this tatty individual! The membrane between the tergites and sternites isn't easy to photograph in normal side view or elevated view, but here I managed to capture it by photographing it in a glass pot looking up from a low angle. The wing shape was not clearcut to me and the few costal hairs I could find to meausre were a bit longer than the last two and probably within range for either species.

female Chrysoperla lucasina showing forewings and costal hair length, North Elmham (Norfolk, UK), 21st June 2025

Another one with tatty wings, or rather one tatty wing. I don't think I would have got this to lucasina from wing shape or length of costal hairs but the brown line through the abdominal membrane was very clear.

female Chrysoperla lucasina showing side of head, abdominal membrane, forewings, costal hair length and tip of abdomen, North Elmham (Norfolk, UK), 26th July 2025

Again this one would be tricky on wing characters alone.

female Chrysoperla lucasina showing abdominal membrane, forewings, costal hair length and tip of abdomen, North Elmham (Norfolk, UK), 5th July 2025

An individual like this prompts me to wonder whether or not the presence of a brown line through the abdominal membrane really is diagnostic. I'm working on the assumption that it is as none of the most recent references suggest otherwise, but this one had quite rounded wings with longer costal hairs than is normal for lucasina and comfortably within range for carnea. If it is correct that the presence of the dark line is diagnostic, and if some lucasina don't have the dark line (as implied by Plant), then surely a lucasina with wings like this and no dark line in the membrane would be misidentified as carnea. I have included an annotated image of the abdomen tip showing measurements as they're used in the paper describing Chrysoperla pallida, though I think it's quite tricky to interpret these precisely as things don't necessarily line up at quite the same angles as shown there. I've also included a photo of the hind tarsal claw as the shape of this is also potentially useful, however I cannot make sense of the descriptions of how this is assessed in a way that applies here.

male Chrysoperla lucasina showing abdominal membrane, forewings, costal hair length, tip of abdomen and hind tarsal claw, Beetley Meadows (Norfolk, UK), 30th May 2025

This was one of three caught the same night.

male Chrysoperla lucasina showing abdominal membrane, forewings, costal hair length, tip of abdomen (before and after clearing) and genitalia, North Elmham (Norfolk, UK), 18th July 2025

There don't seem to be any consistent differences in the genitalia between this species and carnea, though there have been some claims to the contrary in the past. It is difficult to assess things like the relative length of the tip compared to the width as they're angled slightly and don't tend to sit flat even when prepared on a microscope slide with a cover slip firmly pressed down over it.

second male Chrysoperla lucasina showing abdominal membrane, forewings, costal hair length, tip of abdomen (before and after clearing) and genitalia, North Elmham (Norfolk, UK), 18th July 2025

There don't seem to be any consistent differences in the genitalia between this species and carnea, though there have been some claims to the contrary in the past. It is difficult to assess things like the relative length of the tip compared to the width as they're angled slightly and don't tend to sit flat even when prepared on a microscope slide with a cover slip firmly pressed down over it.

third male Chrysoperla lucasina showing abdominal membrane, forewings, costal hair length, tip of abdomen (before and after clearing) and genitalia, North Elmham (Norfolk, UK), 18th July 2025

This was found during the day on the same date that the above three were trapped at home. The dark line on the abdominal membrane was very faint, enough to make me question whether it's really good enough to call it as lucasina on that character. The wings are not convincing either way, either in terms of shape or length of the costal hairs. I may come back to this but for now I'm leaving it as unidentified though I suspect it is another lucasina.

male Chrysoperla sp. showing side of head, abdominal membrane, forewings, costal hair length and tip of abdomen, Wendling Beck Environment Project (Norfolk, UK), 18th July 2025

This individual was identified at the time (2023) as lucasina based on the wing shape, after spending quite a lot of time comparing it to wings of lacewings identified as carnea. I thought that the identification was supported by the length of the costal hairs, shorter than the carnea I had examined by that point, although I had only recently begun to measure these so the sample was small. However it did not have any dark on the membrane between the sternites and tergites and I am no longer convinced that my original identification was correct.

female Chrysoperla sp., identified at the time as Chrysperla lucasina but now considered unproven, showing forewings and close-up of mid costal hairs, North Elmham (Norfolk, UK), 10th September 2023

I caught this one in 2022 and examined it carefully. At the time I was content that the wing shape matched lucasina, though subsequently looking back at the photos I became less convinced. From the photos it seems that the hairs on the costa are short compared to typical Chrysoperla carnea (though they were not measured), so I trusted my original judgement and initially retained this as lucasina. The lip of the abdomen seems long but in other respects (e.g. height of lip compared to chin, length of hairs on lip, presence of dark hairs) it resembled carnea (and not pallida). Henry, Brooks, Johnson & Duelli (1996) failed to find any consistent differences between lucasina and carnea in the abdomen shape. A large proportion of dark hairs appears to be more typical of carnea but is not conclusive. In view of the green membrane between tergites and sternites and as the costal hairs were not measured, I am no longer satisfied that this was certainly lucasina.

male Chrysoperla sp., identified at the time as Chrysperla lucasina but now considered unproven, showing forewings and abdomen tip from side, North Elmham (Norfolk, UK), 29th October 2022

These two older records were identified as lucasina based entirely on the wing shape, but I suspect this was judged from the live insect without flattening them carefully. Again I have no notes or photos to suggest that the membrane between the terigtes and sternites was brown and I no longer consider the identification as lucasina to be proven.

Chrysoperla sp., identified at the time as Chrysperla lucasina but now considered unproven, North Elmham (Norfolk, UK), 13th October 2017

Chrysoperla sp., identified at the time as Chrysperla lucasina but now considered unproven, North Elmham (Norfolk, UK), 16th August 2017