This study addresses the systematics of Malkaridae in New Zealand. We describe 2 new genera and 11 new species from New Zealand, and provide an overview of the systematics of the family.

The taxonomy of Merodon, the largest hoverfly genus in Europe, requires clarification. We revise the Merodon constans species group using classical morphological, geometric morphometric and molecular analyses, and distributional patterns. We provide morphological diagnoses, distributional data, and an illustrated key for 15 species (nine new). Our results indicate the need for an integrative taxonomic approach assessing the diversity and relationships within Merodon.