To optimise vine weevil control this season, ICL urges nurseries to start monitoring for pest grubs and adults now – to enable timely targeting of newly laid eggs in March with Pitcher GR.
“With the recent loss of Thiacloprid, growers cannot afford to do be complacent,” says Sam. “The pest will have overwintered on many UK nurseries in its larval stage with adults emerging soon to start laying eggs. Our award-winning product, Pitcher GR, is a key component of an IPM programme as it uniquely targets the egg as well as the early instar stages.
“Having overwintered feeding on plant roots, the grubs will be easily visible in the root ball; C-shaped and cream in colour they have a brown head. It’s well documented that vine weevil prefer certain plant species such as Camelias, Heucheras, Primulas and Cyclamen. It makes sense to start monitoring with these species; tap out a few pots and inspect the root balls for signs of grubs.
Nocturnal in nature, Sam says growers are unlikely to spot the adult beetles during the day. “It’s best to crop walk and scout at dusk, or preferably at night using a torch,” he says. “Remember, these flightless beetles can migrate on site from neighbouring gardens or fields. All beetles are female and capable of laying large quantities of eggs within days of hatching.
In heated greenhouses, all vine weevil life cycle stages can be present year-round. In unheated or outdoor/field-grown crops, the adults hatch in spring – following an accumulation of degree days. In a warmer spring the beetles will therefore emerge earlier than a cooler one.
To optimise control of the egg stage, ICL recommend applying Pitcher GR just prior to adults emerging which can be mid-late spring. Based on garlic-extract, this granular biorational product can be broadcast over closely spaced container grown crops or applied in a more targeted manner by hand.
“To help ICL customers plan ahead and optimise control, we have developed our ground-breaking digital Plant Health Planner,” explains Sam. “By scheduling timely applications of Pitcher and Seeka nematode products, when temperatures allow, our Plant Health Planner helps optimise control, reminding growers when they need to take action.
“If you have vine weevil on your nursery, it is unlikely you will eliminate it completely,” he warns. “However, by implementing our carefully targeted full IPM programme you can expect to keep this potentially devastating pest adequately controlled.”
Find out more about Pitcher GR here.