Red eyes, mostly black body with a few triangle (ish ) shaped pale marks on abdomen. About 1cm long.
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It's a common hoverfly, found on low growing flowers like Dandelions, Forget-me-nots and so on. If you could see the front legs, you'd see there is a swollen segment on the lower leg, typical of Platycheirus.
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Lat/Lng: 51.6, 0.3
OS grid ref: TQ6097