Nineta flava

A large species of green lacewing, flying between mid May and September.

The large size of this lacewing is sufficient to eliminate most of the commoner species apart from Nineta vittata, but there are other large species that need to be eliminated, and apparently small examples occur sometimes too. The basal segment of the antennae is large, but not twice as long as wide as it is on Nineta vittata.

If using Plant (1997) please note that the Nineta section of the key has been extensively revised to accommodate additional species - refer to Entomologist’s Rec. J. Var. 126 (Canard, Wilton & Plant, 2014) for details (this also corrects an error in Harvey and Plant, 2007). Once vittata is ruled out on the size of the basal antennal segment, check the shape of the edge of the forewing - it should be concave in Nineta flava but not in Nineta pallida (which has not been recorded in Norfolk). Check carefully for this - the concavity is not always obvious in flava. Finally if it looks like flava with costal concavity but the costal cross-veins are dark then keep hold of the specimen and contact me if it's in Norfolk - there are two species that are possible, but neither have been recorded in Britain yet (however it's more likely to be Nineta flava which can have some dark costal cross-veins (see below).

Despite having caught several Nineta vittata, the commoner Nineta flava had eluded me until 2022. This was clearly a good year for them as three came to my garden moth trap and I found another nearby.

Nineta flava showing fore and hind wings, North Elmham (Norfolk, UK), 27th May 2022

female Nineta flava showing size comparison with a male Chrysoperla carnea (below the flava), fore wing, close-up of head showing basal antennal segments, and abdomen tip, North Elmham (Norfolk, UK), 29th June 2022

Unsure about any genitalic differences between flava and other Nineta I thought I'd check this one, but for some reason don't seem to have taken any photos of the abdomen before dissection. Anyway, for what it's worth, here's what I found inside this flava. I've subsequently found French and Spanish papers showing the differences between flava and other Nineta species but these relate to undissected males viewed from the side (and in some cases from below).

male Nineta flava showing internal genitalic structures, North Elmham (Norfolk, UK), 30th July 2022

This individual (which I found resting under a lime leaf during the day) had darkened ends to its costal cross-veins, but this was pretty marginal, so I don't think there's enough cause to suspect either of the European species (guadarramensis or principiae) which have, "Costal cross-veins of forewings more or less entirely darkened or at least darkened at the ends."

Nineta flava showing forewings (3 shots), head showing basal antennal segment and abdomen tip, County School Station (Norfolk, UK), 13th August 2022

The next one (found by Dave Norgate and passed to me for identification) had more extensively darkened costal cross-veins near the base of the wing, and clearly darkened bases to nearly all the costal cross-veins. Arguably this made it a stronger candidate for one of the European species but the only way I was going to know for sure was if I could find a reference that has more detail on how to identify those. I found two papers, firstly a Spanish paper on Iberian Chrysopidae (Los Crispópidos de la Península Ibérica y Baleares (Insecta, Neuropterida, Neuroptera: Chrysopidae) by V J Monserrat (2016). This had diagrams of lateral and dorsal views of male Nineta abdomens of four species (guadarramensis, vittata, flava and pallida). The diagrams for flava matched this individual as expected and one of the species with dark costal cross-veins, guadarramensis, was ruled out, but principiae was not included. I then found the French paper Les Chrysopes du genre Nineta Navás, 1912, en France (Neuroptera, Chrysopidae) by Canard, Cloupeau and Leraut (1998) and this included lateral (and in a couple of cases dorsal) views of male abdomens for principiae, guadarramensis, pallida, flava, inpunctata, vittata and carinthiaca. None of these diagrams quite tallied with the specimen before me but flava was closest and the differences from principiae were, I think, more significant.

male Nineta flava showing base of forewing (including close-up of costa) and abdomen tip (side view before clearing, 3 side views after clearing and one dorsal view), Toftwood, Dereham (Norfolk, UK), 21st June 2024 (specimen collected by Dave Norgate)