Spring Pest Alert: Thrips, Aphids on Hanging Baskets

Posted by Matthew Grassi|April 17, 2019

Avoid thrips resistance by rotating chemicals so that two successive generations are not exposed to the same product.

As the countryside turns to spring, University of Massachusetts (UMass) Extension’s Greenhouse Crops & Floriculture Program advises growers be on the lookout early for thrips and aphids on hanging baskets.

According to the program’s April 8th Greenhouse Update, thrips continue to be observed in greenhouses, and damaging populations have been spotted on geranium, Vinca vine, peppers, and Verbena. Aphids were also detected on Portulaca in the same time frame.

UMass Extension recommends a number of next steps, including regular monitoring of hanging baskets, the use of sticky cards to monitor for adult thrips, and a consistent weekly scouting program to detect the pests before “populations explode.”

Biological controls, specifically the use of sachets of Neoseiulus cucumeris, have proven effective in eradicating thrips, as have parasitoids such as Aphidius colemani in controlling aphid outbreaks. Be sure to deploy any biocontrols as early in the crop cycle as possible, UMass recommends. Conventional insecticides are also an option and, when used, should be rotated between different active ingredient classifications to prevent the development of resistance.