Aphid Killers (Parasites)

Aphidius colemanii

These are tiny flying insects which lay their eggs inside Aphids, turning the dying carcases into "mummies". Widely used in commercial glasshouses, Aphidius colemanii is a highly effective way of reducing aphid numbers. Some growers even keep their aphidius populations going by providing "banker plants" like grasses or nettles where aphids like to congregate. Aphidius works better on small, isolated patches of aphid and the species of Aphidius used depends on the species of aphid present. Aphidius colemani is effective against small aphids such as Myzus persicae and Aphis gossypii. It is not effective against greenfly or blackfly, which are better controlled with lacewings, ladybirds, or aphid midges. (Aphidius ervi is better for control of larger aphids such as Macrosiphum euphorbiae and Aulacorthum solani. See below)

The tiny insects fly around searching out their prey, but you probably won't notice them unless you are looking carefully - they look a bit like a miniature version of a flying ant, but they are in fact technically "braconid wasps" related closer to wasps than to ants.

Soon after you introduce Aphidius you should start to notice round buff-coloured egg shaped lumps replacing the active aphids - this is the sign that aphidius are taking over. The aphids are being "mummified".

This beneficial insect is a native insect to the UK, so it also works outside, but is best in a glasshouse or conservatory where it will stay and reproduce until there are no more Aphids to parasitise. This is best introduced early when temperatures are regularly above 15°C (60°F). To gain quicker effect if the Aphids infestation is bad, it may be best to spray with our Soft Soap before your beneficial insects arrive.

You will receive a tube with developing Aphidius, some of which will be hatched already (depending on the ambient temperature).

Aphidius ervi - for larger aphids

Aphidius ervi is a very similar insect to Aphidius colemani, but it is better for control of larger aphids such as Macrosiphum euphorbiae and Aulacorthum solani. It is usually used as a preventative measure rather than as a control for large outbreaks, as it may take a little longer to get established. (For large outbreaks you might consider insects that eat adult aphids such as lacewings or ladybirds.)