Thrips are an important pest on many crop groups. Besides sucking sap and stunting plants, they also transmit viral diseases to crops. Viral diseases have seriously reduced yield and product quality because there is no cure yet, so the most practical way to limit their development and spread is to control the vector – thrips.
Scientific name: Frankliniella occidentalis
Morphology
Thrips are very small; adults are about 1mm long, black, with a pointed tail and fringed wings. Nymphs are wingless, similar in shape to adults, pale greenish-yellow.
Behaviour and damage
– Thrips are active both day and night; during the day they move fairly quickly and, when disturbed, hide on other leaves or play dead and drop to the ground.
– Adult thrips crawl quickly and nimbly and lay eggs in young leaf tissue. Adults and nymphs usually concentrate on leaf undersides and crawl onto petals to feed.
– Thrips suck sap from young leaves, young shoots and flower buds, causing yellow leaves, pale flowers and deformed, curled petals, reducing ornamental value so flowers fail to meet quality standards. Feeding sites show round, clear oil-drop-like spots with a yellow dot in the centre, at first whitish-yellow and later dark brown. Damaged young shoots are often rough, stiff and brittle, with leaf margins and tips curling up, and plants grow poorly.
– Thrips thrive in dry, hot weather.
– Short life cycle, high reproduction and high resistance to pesticides.
Control measures
– When thrips first appear, spray the plants with water, thoroughly covering leaf undersides.
– Use yellow sticky traps to catch adult thrips.
– When thrips density is high, spray the following product: Pilaravia 155SC, 24ml per 20-litre tank of water. Focus the spray on the undersides of young leaves and young shoots in the early morning or cool afternoon. The product has stomach, contact and two-way systemic action combined with new technology and a dedicated additive, helping growers control thrips faster with a longer-lasting effect, saving costs and care time.
Advisory contact: +84 86 210 5050 (Free)
