Hoverfly

Description:

Black and yellow hoverfly with brownish transparent wings. Somewhat I m not so sure about my ID - the above mentioned species should have some sort of a pattern forming a design resembling a skull or Batman on thorax... but I was wondering if the light was not playing a part in the deception, as those two vertical lines are not always that clearly visible... Anyway, if anyone have a better idea, welcome and thanks in advance!

Habitat:

I my ID is correct, this is a very common Palearctic species, found in variety of habitats, from forests to agricultural lands. Here, observed in Natural Reserve of Jura mountain range, at 900m approx; on edge of a mixed forest, and sunbathing on a board with the map of the Reserve.