DESCRIPTION: Wing length 5 - 8.5mm. A widespread species whose main identification features are different in both sexes. Males have squarish commas on tergites 3 and 4 which partially fuse at the mid-line and which extend into the lateral margins making over 50% of the edge yellow. The females markings are smaller but still extend to the same degree to the margins. Males have a large genital capsule. Both sexes have a grey shining band on t he posterior margins of tergites 2, 3, and 4. BEHAVIOUR: The adult flies feed on pollen and nectar and have a preference for umbellifers. They can be seen in large numbers when joined by migrating specimens or when a mass emergence occurs. Larvae feed on various ground-layer aphids. DISTRIBUTION: Common throughout especially in open habitats. HABITAT: Meadows, woodland clearings, hedgerows, gardens and waste ground. PERIOD: March to November. |