Farmers in New Zealand are being warned to watch for greasy cutworm this spring after unusually high numbers of the pest wiped out whole paddocks of summer forage and maize last season, forcing some to resow. El Niño creates ideal conditions for it, said Derrick Wilson, research associate at the Bioeconomy Science Institute: mild winters let more pupae survive, producing larger moth populations that lay eggs earlier, so the caterpillars appear exactly when crops are establishing and most vulnerable.

Maize is the favourite target, but cutworm also destroys chicory, turnip and forage rape seedlings; on one Taranaki farm it stripped all the clover from a two- to three-year-old pasture. 'By the time you see significant signs of feeding, the damage is already done,' said Barenbrug pasture specialist Graham Kerr, urging farmers, resellers and consultants planning spring-sown crops to prepare now.

Ōtorohanga dairy farmer Bruce Collinson-Smith, who direct-drills about 180 hectares of maize, chicory, turnips and swedes a year, lost 40% of his spring-2024 turnips in a week and had to resow. He now sprays every crop for cutworm, timed around the two-leaf stage so that one pass is usually enough. 'Anything that wants to kill a crop has got worse in the past five to seven years,' he said.

Mr Wilson's advice is preparation and early action: control weeds such as plantain and dock that host the pest; leave the paddock free of crops and weeds for at least six weeks to break the life cycle; use insecticide-treated seed for early protection, which also helps against black beetle and Argentine stem weevil; and scout crops regularly so that any infestation is caught in time.

The warning lands as a strong El Niño is forecast to bring a dry summer to much of the country — the same pattern that favours the pest.

Source: Farmers Weekly NZ