Monitoring for invertebrate pests in truffle orchards

Page last updated: Tuesday, 26 October 2021 - 7:22am

Please note: This content may be out of date and is currently under review.

Slugs and slaters are among the most important pests of truffles. When abundant, they cause significant damage to truffles. The level of slug and slater pressure in your orchard as well as the presence of other pest and predator invertebrates can be gauged by monitoring using the tile technique.

From monitoring that has taken place in truffle orchards across Australia we have found that pest type, abundance, distribution and seasonality varies from orchard to orchard and season to season.  By conducting your own regular monitoring you will gain an understanding of which pests are in your orchard, their abundance, orchard hot spots and the impact of any control methods you use.

We recommend monitoring with bathroom tiles and making a record of what you find. Attached are two versions of score sheets you may like to use, one for slugs and slaters the other more detailed, as well as a field guide with colour photos of the main pests and predators you are likely to find.

many slugs present on an overturned tile
After two days tiles should be checked and the number of slugs, slaters and other invertebrates of interest counted.

What you will need and the method are outlined below.

You will need

  • Fifty, 20 cm square bathroom tiles. Large orchards would require more tiles to ensure good coverage and that hot spots are not missed.
  • Flaky bran (available from a feed merchant or hardware store) and teaspoon.
  • Score sheet.

Method

  • Plan the location of tiles so they are evenly spaced across the orchard.
  • Place tiles close to a tree – this is where we find slugs and slaters will occur; they are out of the way of orchard operations; and more easily relocated.
  • Before placing each tile, clear the ground the tile will sit on to remove leaves and small pebbles. This makes observing and counting easier.
  • Place one heaped teaspoon of flaky bran on the ground and place the tile on top.
  • Two days later check under each tile. Record the numbers of invertebrates present.
  • We recommend removing bran after monitoring so that slugs and slaters can redistribute as normal so as not to bias future monitoring.
  • Lean tile up against the tree until monitoring is repeated.

Repeat monitoring every four weeks or as time permits. Monitoring can be done before and after a control technique is applied to help determine the effectiveness of the control, although be aware that some control methods may take more time to have an impact on pest levels.

More detail of what occurs under tiles than just the total number of slugs and slaters can be recorded if desired. To help with identification of the more common pests and predators a field guide photo sheet is available showing:

  • the main species of slugs and millipedes
  • slaters
  • springtails (collembolans)
  • the main species of earwigs – pest and predatory
  • beetle adults:
    • potential pests: click beetle, vegetable beetle, African black beetle;
    • predators: carabids, staphylinids.

For very abundant unidentified fauna, use the MyPest Guide Reporter app, or collect samples and contact one of the DPIRD staff below. If you send photos in for identification please ensure they are in focus and close enough to discern features.