To further differentiate between the Chrysopinae species that have a green second antennal segment, you first need to look whether there is a black spot present between the antennae (see image below).
If your specimen has a black spot see below, if it has no black spot click here. Be careful for bits of dirt or lepidopteran scales looking like spots.
Apertochrysa ventralis
An important feature is the glossy black underside of the abdomen. Other diagnostic features are shown in the below image.
Apertochrysa prasina
One important character for this species is the dark spots at the base of the Costa, sometimes these are difficult to see, so have a good look at all four wings.
Chrysopa pallens
Defining features are given in the below image.
