Aphidius colemani
A 2–3 mm black parasitoid wasp that lays a single egg inside an aphid. The larva eats the aphid from within and pupates in its skin, leaving the swollen, golden-brown shell growers call a mummy. It is sold for the small aphids — green peach, melon and tobacco aphid — and is released preventively under glass, starting soon after planting, because the first mummies take 10–14 days to appear.
At a glance
- Mode
- Parasitoid — one egg per host
- Rate
- 0.25–4 /m² per release, weekly
- Ships as
- Mummies in a bottle of carrier
- Temp
- 18–25 °C best; weak above 30 °C
- Humidity
- 60–80 % RH (US suppliers)
- Setting
- Greenhouse and indoor crops
How it works
A female checks each aphid by drumming it with her antennae, then stabs it with her ovipositor and leaves one egg — Koppert times the whole act at under half a second. Second and third instars are preferred, but any stage can be used, winged adults included. Suppliers put her output at about 100 to up to 300 eggs, with up to 200–300 aphids attacked, over an adult life of about 10–14 days.
The parasitised aphid does not die straight away. One stung as a young nymph never breeds; one stung as a fourth instar or adult still produces young for up to two more days. Some 7–12 days after the egg is laid the aphid swells into a mummy, and the new wasp cuts a round hole and leaves four to six days later — about two weeks from egg to adult at summer temperatures. That lag is why the wasp is used ahead of the aphid, not after it: a release that is working shows nothing for the first week.
Is it established?
The mummy is the evidence, not the dead aphid. Count mummies on the same leaves you count aphids on — the ratio is the read on whether the program is holding.
- DAYS 1–3Adults emerge from the mummies in the carrier and disperse
- DAYS 10–14First golden-brown mummies on leaves near the release points
- DAYS 14–21Mummies with a neat round exit hole — the next generation is out
- AFTERMummies spreading through the colonies; keep releasing until aphids are under control
Release & handling
Mummies arrive in a small bottle of carrier — wood chips in Koppert's pack, buckwheat hulls in some others. Release them as soon as they arrive: Arbico says within 18 hours, and Koppert allows one to two days at 8–10 °C in the dark if you must hold them. Tip the carrier onto rockwool slabs, horizontal leaves or into release boxes hung in the crop — never onto the soil — and keep it dry and undisturbed for a few days while the adults emerge.
Release the same day
Adults begin emerging within one to three days of release. The sooner the mummies are in the crop, the sooner the wasps are working.
8–10 °C, dark
One to two days at most (Koppert); release as soon as possible.
Dry, off the soil
On rockwool slabs, horizontal leaves or in release boxes, out of direct sun and away from irrigation. Extra points near colonies.
Leave the carrier
Do not move or wet it for a few days. Go easy on yellow sticky cards, which trap the wasps too: one per 100 plants at most, or use blue cards.
Pesticide sensitivity
UC IPM rates pyrethroids, acetamiprid and spinosad as highly harmful to parasitoids, azadirachtin (neem) as moderately to highly harmful, soil-applied imidacloprid as moderately harmful, and soap and oil as low risk. Beauveria bassiana can infect and kill the adult wasps. Check a product →
When to choose something else
The wasp is a preventive tool for small aphids in warm, protected crops. Reach for something else when:
- Colonies are already large — add the gall midge Aphidoletes aphidimyza or lacewing larvae on the hot spots and keep the wasp going underneath
- The aphid is potato or foxglove aphid — colemani stings potato aphid but cannot complete its development, and it is not an effective control for foxglove aphid either; use Aphidius ervi
- The house runs above 30 °C for long spells — larval development stops at 30–31 °C
- It is high summer and mummies are failing to hatch wasps — hyperparasitoids can wipe out parasitoid populations in summer, so switch to or add a predator
Where to buy
Suppliers listed alphabetically, not ranked. helpfulbugs takes no commission and does not sell insects.
- Arbico Organics500 / 1,000 / 5,000US
- Buglogical500 / 1,000 / 5,000US
- Koppert (Aphipar)500 / 1,000 / 5,000GLOBAL
- Sound Horticulture500 / 1,000 / 5,000US
Aphidius colemani by target
Rate and timing differ by what you are releasing it against. Each page below is the program for one pest.