AgPest » AgPest » Category » Grass-grub

Consider direct drilling to control pests

AgPest — Sat, 14 Oct 2017 19:45:59 +0000

For pastures badly affected by either grass grub or porina over winter and needing renewal, consider direct drilling. This will preserve naturally occurring diseases of these pests that are building up in the soil and which will provide long term population regulation. Leave sowing as late as possible as both pests, especially in the south, may still be feeding and could devastate establishing seedlings. Be aware that slugs and clover root weevil may also be present in damaging numbers.

Porina & Grass Grub Damage

AgPest — Fri, 11 Aug 2017 23:17:02 +0000

Porina and grass grub damage is showing in lower North Island. The only option available to protect pasture now is insecticide

Grass grub and porina damage evident

AgPest — Sun, 09 Jul 2017 21:38:47 +0000

Grass grub and porina damage will now be evident in most areas. Grass grub damage is indicated initially by loss of clover and subsequently by patches of pasture turning yellow. At this time of year these patches become soft under foot and are prone to pugging. Porina damage will show as bare areas of pasture often with only weed plant species present. Conventional insecticide is the only control option likely to give control of either pest. By now production losses have already occurred but treatment may save the affected pastures.

Grass grub and porina

AgPest — Sun, 04 Jun 2017 21:44:45 +0000

Grass grub and porina damage will now be evident in most areas. By now production losses have already occurred but treatment may save the affected pastures. Conventional insecticide is the only control option likely to give control of grass grub in all areas and of porina in the South Island. North Island porina are still susceptible to diflubenzuron until mid-July. Careful consideration needs to be given to control options as spring growth may occur before damage becomes such that plants are lost from pastures.05

Grass grub and porina damage may be showing

AgPest — Thu, 04 May 2017 21:01:06 +0000

Grass grub or porina damage may be showing. Grass grub damage is indicated initially by loss of clover, patches of pasture turning yellow and becoming soft under foot. Porina damage appears as small (approx 5 cm dia.) areas of bare ground. Both pests should be controlled as early as possible to maximise returns and protect long term pasture production and quality. Heavy rolling, high stocking rates or N application may provide some relief from grass grub but insecticide (diazinon) may be the only recourse. It is too late to control porina using diflubenzuron in most southern areas, conventional insecticide is still effective. Caterpillars from late February/March flights in the North Island and the South Island West Coast are still susceptible to diflubenzuron.

If grass grub or porina are of concern…

AgPest — Sun, 02 Apr 2017 23:03:10 +0000

In areas where grass grub or porina are a concern inspect pastures now for early damage. Grass grub damage is indicated initially by loss of clover and subsequently by patches of pasture turning yellow and later becoming soft under foot. Porina damage initially appears as small (approx 5 cm dia.) areas of bare ground. Both pests should be controlled as early as possible to maximise returns and protect long term pasture production and quality. Although heavy rolling, high stocking rates and application of nitrogen can lessen damage, conventional insecticide (diazinon) may be the only recourse. It is now generally too late to obtain good control of porina using diflubenzuron, although in much of the North Island caterpillars from February/March flights are still susceptible. In most cases porina control now needs to be by conventional insecticide.

Grass grub

AgPest — Sun, 12 Mar 2017 22:27:27 +0000

In grass grub prone areas 2 and 3 year old pastures should be inspected to determine if potentially damaging levels are present. Early treatment will offer most protection and maximise returns from the cost of intervention.

Pasture establishment – direct drilling

AgPest — Tue, 28 Feb 2017 22:16:20 +0000

If pasture establishment by direct drilling is going to be used check those pastures for slugs and grass grub as even low numbers can devastate young seedlings of pasture or crop plants. Wet sacks can be laid in the paddock, slugs will shelter under these and be seen on the pasture surface if inspected after 2-3 days – more than 2 slugs per sack could result in seedling loss. To detect grass grub dig at least 10 15 x15 cm holes 15 cm deep and search the soil – as few as 1 grub/hole could cause damage.

Grass grub prone areas

AgPest — Wed, 22 Feb 2017 23:00:20 +0000

Grass grub prone areas

AgPest — Wed, 22 Feb 2017 23:00:19 +0000