Pyrilla Control

Symptoms

Look for pale yellow to brown hopper insects with a pointed snout on the underside of leaves, jumping when disturbed. Leaves turn yellow and dry from the tips, and a sticky honeydew covers the foliage on which black sooty mould develops, giving the crop a blackened look. Heavy attack causes drying of leaves.

Damage

Pyrilla (Pyrilla perpusilla) is a sap sucking hopper that weakens plants and reduces photosynthesis through sooty mould on honeydew. Severe outbreaks cause leaf drying and lower cane weight, juice quality and sugar recovery. It tends to flare up in humid weather and on lush, heavily fertilised crops.

Organic & cultural control

Conserve and encourage the natural parasitoid Epiricania melanoleuca, which is a very effective biocontrol of pyrilla, by collecting and releasing its egg masses and cocoons in affected fields. Detrash lower leaves to reduce shelter, avoid excess nitrogen, and protect other natural enemies. In most cases this parasitoid alone keeps pyrilla under control.

Chemical control

Spraying is needed only in severe outbreaks where the parasitoid is absent, since chemicals also kill the helpful Epiricania. When essential, recommended actives such as chlorpyriphos or malathion may be used as advised. Always read and follow the product label, observe the pre-harvest interval, and consult your KVK or a qualified agronomist before spraying.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Avoid excess nitrogen and dense planting that create the lush humid canopy pyrilla loves. Detrash lower leaves regularly to reduce shelter and humidity. Protect and multiply the parasitoid Epiricania, monitor leaf undersides through the humid months, and avoid blanket spraying that destroys this natural control.