Sexing a hoverfly

As mentioned in the previous post, differentiating between sexes of insects can often be tricky but in the case of hoverflies and the Marmalade Hoverfly Episyrphus balteatus in particular, it is relatively straightforward, especially with two similar photographs to refer to. 
In males the area covered by their compound eyes is significantly larger, with the left and right ‘eyes’ meeting at the central dorsal line. The scientific term for this eye arrangement is holoptic and is typical of several male members of the diptera (true fly) family.
Females eye clusters are smaller and don’t meet; instead an obvious separation is clear.

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