Slug
Snails and Slugs
Snails and slugs can cause significant seedling losses in direct-drilled and mulch-planted pastures in wet conditions or following cool wet summers.
The best method of checking for them is to put out bait stations before sowing. Squares of cardboard (30 × 30cm) held down by a stone or wet hessian bags are suitable. Place these near watercourses, in damp spots and near trees. If there are more than 2–3 snails or slugs at the bait stations, baiting with methiocarb is recommended. Where large numbers are found, thorough cultivation might be the best option for killing adults and eggs.
When herbicides have been used to kill existing pasture, and dry residue remains, burning before drilling can greatly reduce populations.
Earth Mites
The most common pests of new pastures on the Tablelands and Slopes are red- legged earth mites and blue oat mites. They can cause enormous damage, especially if they attack the cotyledon, or seed leaf, of the germinating legume seedlings.
If direct-drilling or mulch plantings are to take place in autumn, early prespraying in spring and autumn can reduce numbers in areas where earth mites occur regularly.
Spring spray: Apply an appropriate miticide such as dimethoate or omethoate when spraying thistles, spray-fallowing or pasture-topping in late spring. This kills most of the year’s final adult population and greatly reduces the number of over- summering eggs.
Autumn knockdown: When the autumn break coincides with maximum temperatures below 22?C, the mites will hatch. Two or three weeks later the first generation will be mature and ready to lay eggs. If sufficient numbers are present and any weed spraying is being done, include a miticide at this time.
Black Field Crickets
These spasmodic pests of direct-drilled and mulch-planted pastures can be found under plant debris, in cracks in the ground and under clods. Field inspection before sowing is essential. They can be controlled by baiting before sowing or cultivation.
Pasture Cockchafers
This group includes African black beetle, pruinose scarab and dusky pasture scarab. Larvae, or white curl grubs, can cause major losses of establishing grass and clover seedlings in direct-drilled and mulch-planted pastures. Adult African black beetles can also damage grass seedlings in late autumn and winter.
Larvae of the African black beetle are active from early summer to late February. Where these are the only scarabs, autumn planting from mid March onwards should avoid significant losses. Pruinose scarab and dusky pasture scarab larvae feed actively from February to spring. Yellow- headed cockchafer numbers increase following dry springs and summers, particularly after a succession of dry years.
A thorough check of the top 10cm of soil before sowing is the only way to check for these pests. If white curl grubs are found, thorough cultivation will give easy control.
