Powerful new bioinsecticide for vine weevil – Lalguard M52

Earlier this month, at the Four Oaks Trade Show, we launched a highly efficacious new Metarhizium-based bioinsecticide, Lalguard M52 GR – delivering quick control of Black Vine Weevil larvae in growing media

“Easy to use, it is growing media incorporated and highly compatible with existing biological and chemical crop protection products,” explains Sam Rivers, ICL technical manager for controls. “Based on spores of the soil-borne insect pathogenic fungus Metarhizum brunneum strain Ma43, Lalguard M52 offers the advantage that it infects on contact – so does not need to be ingested.

“At 15-30°C, infected immature larvae can be killed within just three days.  On the other hand, control of larger larvae may take longer if temperatures fall outside this range.  Meanwhile, vine weevil eggs, pupae and adult beetle stages show some susceptibility – adding to the overall effectiveness of control.”

Even before Exemptor (thiacloprid) was withdrawn, vine weevil was estimated to cost UK horticulture £40million/year – £4billion worldwide. Since the loss of thiacloprid, pest pressure has risen and UK growers are turning to robust IPM control programmes.

“Growers should monitor carefully for the pest, quarantine new plants coming on to the nursery and implement bespoke IPM programmes,” says Sam. “Carefully planned, these programmes should incorporate beneficial nematodes to target larvae along with the biorational Pitcher GR – which has proven efficacy against vine weevil eggs.  To optimise control of this potentially devastating pest, Lalguard M52 will play an additional valuable role incorporated into these programmes.

“Against a backdrop of changing industry culture, new laws such as the SUD and environmental ethics, bioinsecticides – such as Lalguard M52 – offer practical benefits. While not a silver bullet, as part of a planned IPM approach this new bioinsecticide will play an important role helping combat vine weevil on nurseries in the UK and Ireland.”

Available in 10kg packs, Lalguard M52 is recommended for incorporation in growing media at a rate of 0.5kg/m3.  While the insect pathogenic fungal spores are likely to persist in growing media for up to a year, treated growing media should be used within 14 days.