Beneficial insects and yellow sticky traps

What they are

Beneficial insects are bugs that eat pests or use them to raise their young. They're bought alive, in sachets or little bottles, and released into the grow. This is called biological control: instead of a treatment, a natural enemy.

The ones in the game

Phytoseiulus persimilis: a reddish mite, smaller than a pinhead, that only eats spider mite. It's very hungry, but it needs humid air (over 60 %) and suffers in the heat.

Amblyseius (cucumeris or swirskii): a mite that eats thrips larvae; swirskii also eats whitefly eggs and larvae.

Encarsia formosa: a wasp less than 1 mm long that lays its eggs inside whitefly larvae. The larva turns black and, instead of a fly, another wasp comes out. It doesn't sting people.

Ampelomyces quisqualis: it's not a bug, it's a fungus that lives off powdery mildew. It's sprayed on the plants, gets into the white spots of the powdery mildew and dries them up. It's better for preventing than for curing, and fungicides (like sulfur) kill it.

How to use them

They're released early: when the first bugs show up, or before, as prevention. They don't wipe out the pest overnight: they bring it down and keep it under control. With a very advanced pest they arrive too late.

They're living things: they need their climate (usually 20 to 28 °C and medium or high humidity) and they die with insecticides. Potassium soap, neem oil and sulfur harm them too.

Yellow sticky traps

They're yellow cards with glue. Many flying bugs are attracted to yellow: whitefly, thrips and fungus gnats get stuck. (For thrips, blue traps are also used.)

They're mainly for monitoring: if stuck bugs show up, you know there's a pest before you see damage on the leaves. They catch some, but they don't cure a pest. Against spider mite (which doesn't fly) and fungi they're useless.

Careful: they also catch the beneficial insects that fly, like encarsia. With wasps released, few traps or none are used.