Cucumber: monitoring strategy for flying thrips

To measure is to know, install blue sticky traps in your crops to detect thrips on time.

In this time of year we advise cucumber and gherkin growers in Western Europe to install traps in their greenhouses. “In the beginning of a new cultivation period, growers should hang these above their plants,” says Wesley Akkermans, Sustainable Crop Management Specialist at Biobest. “This is the place where thrips establishes itself first.”

Many pest insects like whitefly, leaf miners and aphids are attracted by the colour yellow. Thrips, one of the most common pests in cucumbers, don’t dislike yellow, but their true favourite is blue. Moreover beneficials like parasitic wasps are not attracted by this colour.

The rule of thumb for blue Biobest’s Bug-Scan^® traps is 20-40 per hectare of protected crops. To monitor the population evolution properly a weekly or two weekly thrips ‘check and count’ will do.

When thrips has been detected, it is important to react promptly with curative control measures, for example the introduction of predatory mites like Amblyseius swirskii and/or Amblyseius cucumeris. “If in the past thrips appear on a frequent basis, we advise to apply these mites as a preventive strategy. When releasing A. swirskii, combine this with Nutrimite™ to give your predatory mites a boost and built a stronger army more quickly” says Wesley. “Also in this case frequent monitoring remains advisable.”