Whitefly - Entocare Biologische Gewasbescherming

Damage Species Biological control Products

How to recognize whitefly

Despite their name, whiteflies are actually not flies. Instead, they belong to the group of true bugs, like aphids, mealy bugs and scale insects. Adults are 2-3 mm, have wings and have the ability to fly. Only early stage larvae have legs and are mobile. The younger stages usually settle on the underside of the leaf. The larvae are oval-shaped and translucent white to yellow. The last larval stage is a cocoon, which looks like a little box on the leaves. Adult whiteflies will emerge through a T-shaped tear in the cocoon.

With their specially adapted mouth whiteflies puncture the phloem vessels of plants. Because of the high pressure in the phloem vessels plant saps will stream in and lead to an overdose of sugar, which whiteflies excrete in the form of honeydew.

Whitefly damage

Whitefly is a big problem in greenhouse crops. Serious infestations can cause a big swarm of whiteflies when touched. Whiteflies, and the larvae in particular, feed on plant saps and excrete the surplus of sugars as honeydew. Honeydew will make the plants sticky. In addition, honeydew can act as a growth medium for black sooty mold fungus which will turn the leaves black and hamper photosynthesis. Whiteflies are also known as important virus transmitters.

Common whitefly species

Greenhouse whitefly

Tobacco whitefly

Cabbage whitefly

Biological control of whitefly

One of the first biological control agents that was sold commercially against whitefly was the parasitoid Encarsia formosa, EN-STRIP. This product is still being used very often and forms an important part of IPM or biological control of whitefly in many crops. Besides Encarsia formosa many other products are developed and available. These products can often be combined with Encarsia formosa. An important product is the predatory bug MIRICAL, Macrolophus pygmaeus. Especially in hairy crops with many trichomes and soft leaves, MIRICAL can be a very effective control agent of whitefly. In addition, other predatory mites like LIMONICA and SWIRSKI MITE are very capable control agents of whitefly. YELLOW STICKY TRAPS are used for quick monitoring of whitefly and catch a part of the pest population.

The choice of a certain product or strategy for biological control of whitefly depends on the crop, cultivation type and pest pressure and tolerance. In greenhouses in the Netherlands two whitefly species are most present. Which of these two species is present determines the control strategy: while EN-STRIP (Encarsia formosa) prefers greenhouse whitefly, ERCAL (Eretmocerus eremicus) prefers tobacco whitefly. ENERMIX is a combination of these two parasitoids and is the best choice for situations where it is not known which whitefly species is present.