Aphidius, a small parasitic wasp, specializes in parasitizing aphid species such as green peach aphid (Myzus persicae), melon aphid (Aphis gossypii), and cow pea aphid (Aphis craccivora), among others.

It is widely recognized for its efficacy in both indoor and outdoor crops like capsicum, cucumber, tomato, chrysanthemum, and various ornamentals, as part of integrated pest management programs.

Measuring between 3 to 5 mm, Aphidius is a black wasp. The female wasp lays an egg inside an aphid, which then hatches into a larva. The larva feeds on the aphid's internal tissues, eventually causing its death. Aphidius parasitizes both immature and adult aphids, including winged and wingless forms.

After feeding, the Aphidius larva pupates inside the aphid's body and forms a cocoon, giving the aphid's body a distinctive gold or bronze appearance known as an aphid "mummy."

Upon maturation, the adult wasp chews a precise circular hole in the mummy's abdomen to emerge. This emergence hole is visible once the Aphidius has completed its development.

Adult Aphidius wasps primarily feed on plant nectar and honeydew produced by aphids. The females are highly mobile, actively searching for aphid colonies, even small ones.

Naturally occurring in the northern regions of New Zealand, Aphidius may also be present in home gardens during late spring, summer, and early autumn. However, their numbers are often insufficient to effectively control aphids in these settings.

Aphidius poses no threat to humans or animals, and it is not expected to have any adverse environmental impacts.