Chrysotoxum verralli Collin, 1940
Split from C. octomaculatum by Collin (1940). Early records of C. octomaculatum are likely to prove to be this species.
Biology & ecology:
This species has been reared from larvae found in a nest of the black ant Lasius niger. Pupae have been found under a stone, and females seen ovipositing, close to the entrances of ants nests. It is found on well drained soils usually near the shelter of trees or hedgerows. Typical situations include grassy places in scrub, woodland rides and glades or on the fringes of heathland. They are often seen resting on vegetation, and occasionally visit flowers such as bramble Rubus sp. and Dog Rose Rosa canina.
This is primarily a southern and eastern species that occupies a climate envelope that is largely hot in the summer and cold and dry in the winter.
Status & conservation:
There was a substantial decline in occurrence to the late 1990s, but there appears to have been some recovery subsequently.