Melangyna novaezelandiae

Melangyna novaezelandiae, commonly referred to as the large hoverfly, is a hoverfly species found in New Zealand. They are widespread throughout the country and abundant during summer months. They occur in a variety of habitats, including in subalpine and agricultural zones. As adults, they are around 9–12 millimetres in length, with a blackish body that has yellowish markings on the abdomen. The larvae vaguely resemble green slugs. The adults live for around 19–45 days and lay their eggs near aphid colonies. As adults, they feed on pollen and nectar from a wide range of flower species. Their pollen diet is considered to be essential for the females to produce eggs. Because of this, females tend to feed on pollen more than males. The larvae are predators and feed on aphids, but will also target Lepidoptera larvae such as Pieris rapae. Because of this diet, the larvae have been considered for use as a biocontrol agent. The species was first described in 1849 by English entomologist Francis Walker. A later description, however, is the main basis for this species. They are parasitised by Diplazon laetatorius, an Ichneumonidae wasp introduced to New Zealand.