Apertochrysa prasina (formerly Dichochrysa prasina)

A common species, flying between mid June and August.

Like Apertochrysa ventralis and Chrysopa pallens, this species has a black spot between the bases of the antennae. You should look at the underside of the abdomen, preferably before the insect is dead and dried-up, to eliminate ventralis, as that has black on the lower surface of the abdomen (after death, prasina may also darken making it harder to tell them apart from ventralis). Note that you cannot usually see the black ventral surface of ventralis on a side view photo. Separation from pallens is a little harder but prasina shows a small dark spot at the base of the costa on all wings and the basal cross-vein is dark. The palps are also ringed dark on prasina but not on pallens. Plant (1997) gives an additional difference in the number of spots on the head - 3 or 5 including the one between the antenna on prasina and 7 on pallens including a pair immediately in front of the antennal bases - however the figure showing the head of pallens appears to be an exact duplicate of the figure for prasina, presumably an error.

Apertochrysa prasina, North Elmham (Norfolk, UK), 3rd July 2020

Apertochrysa prasina, North Elmham (Norfolk, UK), 18th July 2018

2x Apertochrysa prasina, North Elmham (Norfolk, UK), 19th July 2019

Here is an example of how a poorly-preserved abdomen can turn blackish after death, potentially making it difficult to tell from Apertochrysa ventralis. It's always a good idea to check the underside of the abdomen while the insect is still alive or freshly dead.

male Apertochrysa prasina, North Elmham (Norfolk, UK), 18th July 2022

In case a need should arise to identify an example after the abdomen has turned black I am looking out for other characters that might be useful. I'm not sure I've found any yet - I will keep looking...

second male Apertochrysa prasina showing forewing (including close-up of mid costa) and abdomen from side (before and after clearing), North Elmham (Norfolk, UK), 18th July 2022

Apertochrysa prasina, North Elmham (Norfolk, UK), 25th June 2023

Apertochrysa prasina, North Elmham (Norfolk, UK), 20th July 2018

Apertochrysa prasina, North Elmham (Norfolk, UK), 21st June 2017

Apertochrysa prasina, North Elmham (Norfolk, UK), 23rd July 2016

Apertochrysa prasina, North Elmham (Norfolk, UK), 28th July 2016

Apertochrysa prasina, North Elmham (Norfolk, UK), 29th July 2016