Amblyseius swirskii is commonly used to control whitefly and thrips in greenhouse vegetables (especially cucumber, pepper and eggplant) and some ornamental crops.Since Amblyseius swirskii is not susceptible to diapause it can be used throughout much of the season. This species is considered a generalist predator, and readily consumes small soft-bodied pest species as well as pollen or plant exudates. Amblyseius swirskii has attracted substantial interest as a biological control agent of mites, thrips and whiteflies in greenhouse and nursery crops. The mites are released directly in the crops in bran or vermiculite carriers sprinkled on the leaves or substrates.
Amblyseius swirskii is documented to feed and reproduce on a wide range of prey from several orders, including thrips (western flower, onion, melon, and chilli), whiteflies (greenhouse and silverleaf) and plant feeding spider mites.
The generalist predatory mite A. swirskii is widely used against other pests such as thrips and whiteflies and is also very effective in controlling broad mites. Amblyseius is a beneficial predatory mite endemic to the Eastern Mediterranean region. This species is considered a generalist predator, and readily consumes small soft-bodied pest species as well as pollen or plant exudates. Amblyseius swirskii has attracted substantial interest as a biological control agent of mites, broad mites, thrips and whiteflies in greenhouse.
Thrips definitely count as unwelcome guests, but it's not always easy to find out how the pest got into the greenhouse or field concerned.
Generally speaking, there are three routes that thrips take when getting into a crop:
- They were already there
Thrips are experts at hide-and-seek - especially hiding. In winter, the insect hides away in sheltered spots, in crevices, on plant waste, or in the ground. Their pupae are also concealed in the soil. Thorough disinfection is therefore very important: you can do this as soon as the crop has been cleared out of the greenhouse or field.
- They fly into the greenhouse
Adults can fly into the greenhouse through the vents. These may be native species and thrips from neighbouring greenhouses. Installing insect netting in the vents can certainly help, but it is not always enough. If the infestation level is high, they can simply fly in through the doors. To prevent this, some growers use overpressure in the greenhouse.
- They come in with plant material
Larvae and eggs can hitch a ride on cuttings or young plants and are almost invisible. The existence of this route into a greenhouse sometimes leads to discussions or arguments between the grower and the supplier of the plant material. You can avoid this by making solid agreements. If the plant nursery does not use chemical products with a long-lasting residual effect, it is easier for the grower to build up a population of natural enemies.
Thrips infestations often start along paths and in warm places. From there, the insect moves further into the greenhouse or field crop, either under its own power by flying or drifting with the air. It can also hitch a ride on materials.
Western flower thrips (Frankliniella occidentalis) generally makes itself at home in the upper levels of the crop and in the flowers. Onion thrips (Thrips tabaci) is found everywhere, through it prefers the underside of young leaves. Echinothrips americanus, Impatiens thrips starts off low down in the crop, on the underside of leaves near the veins. These thrips are also found on weeds in the greenhouse; a good reason to put weed control at the top of your to-do list!