Bug-on-bug Warfare – Tackling Glasshouse Whitefly

Plants grown in glasshouses are highly susceptible to pests and diseases due to the warm, damp conditions.

In our glasshouses nursery at Hampton Court Palace, we use an Integrated Pest Management Programme (IPM) which uses biological pest controls alongside cultural, physical and (sparingly) chemical controls to minimise crop damage by pests and diseases.

Encarsia formosa eggs
Encarsia Formosa eggs

‘Biological control’ is the term used to describe predatory insects and organisms that feed on undesirable pests. A common pest is glasshouse whitefly which reproduce in huge numbers and cause unsightly damage to plants such as Lantana (of which we hold the National Plant Collection). To combat the whitefly, we buy the tiny parasitic wasp Encarsia Formosa as eggs (on hanging pieces of card), which hatch and lay their own eggs inside whitefly larvae. The parasitized larva turns black and the hatched wasp leaves a visible exit hole.

Parasitized whitefly larvae
Parasitized whitefly larvae © Bioline AgroSciences

We also spray Pyrethrum and use yellow sticky traps to keep whitefly numbers down until the Lantanas are put outside on display in the summer when they tend to disperse in the wind and cooler climate.

Sticky traps

Amy Borthwick
Skilled Gardener, Glasshouse Nursery

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