Farmers Warned of Grassland Pests Risk01 November 2013
NEW ZEALAND – Farmers are being warned that numbers of grassland pests, porina and black beetle, will be ‘larger than normal’.
Conditions for pasture pests have been perfect, according Dr Alison Popay at AgResearch who blames the mild winter and warm spring on the grim outlook.
She has advised that porina are grazers that eat all ground level herbage, and the amount of damage is relative to population size.
Expect long-term pasture quality and production to reduce, especially in older grass pastures two to three years out of cultivation, commented Dr Popay.
What’s more, the issue should be tackled now, and if it gets bad, an insect growth regulator can be used.
“This time of year, particularly in porina prone areas, the adult insects start to fly; they will be banging into farmers’ windows as they are attracted to light,”
“Farmers that are constantly battling against this pest can continue paddock monitoring and plan to spray four months after the sighting flying moths with the insect growth regulator Diflubenzuron.”
A further threat is posed by rising numbers of Black Beetle, an insect that rests over winter and then becomes active in spring.
“Their ability to feed dictates their egg-laying cycle, so this year we are likely to have an earlier and more successful hatching,” said Dr Popay.
“If these warm conditions continue and high soil moistures don’t reduce survival of the very young larvae, black beetle will be on the increase.
“Awareness will help farmers plan for combat strategies to make up for the feed consumed by this pest. These may include putting in a maize silage block or buying in additional feed if appropriate.”
AgResearch New Zealand recommends the pestweb website, where information about porina and black beetle can be found.
The data base is newly updated, detailing the pest, its biology and control measures.
“One of the site’s key features is the ability to help farmers identify a particular weed or insect pest they find on the farm through a simple query and response system,” said AgResearch weed scientist Dr Katherine Tozer.
“We also took the opportunity to update the pest search function, improve the viewability of the images on the site and expanded our PestAlerts service.”
TheCattleSite News Desk