A Workshop on Integrated Pest Management (IPM), with entomologists Paul Horne & Jessica Page was hosted by Torquay Landcare on October 3 at the Landcare Centre, Modewarre.
This was a workshop Torquay Landcare members had been promising ourselves for two years so we are especially grateful to DPI and CCMA who contributed $1,100 towards costs (with TLG contributing $500). Numbers needed to be restricted but there were thirteen intrigued participants, ranging from broadacre cropping & grazing to those focused on small acreages.
Implementing Integrated Pest Management
Paul Horne spent an hour explaining the principles of Integrated Pest Management (IPM) focusing on cases he had encountered in his research and consultancy career. To help us understand the need for IPM he demonstrated occasions where the annual, ‘just in case’ insecticide spraying of a crop through use of a broad spectrum spray such as pyrethrum actually led to what he called ‘pest flare’ – i.e. the insecticide actually promotes an increase in the pests! Paul explained that the reason this ‘flare’ occurs is that the all purpose spray kills both pests and predators. The life cycle of the pests are generally much faster than that of the natural predators; so without the presence of the predators (killed by the spray), the second generation of pests multiplies exponentially.
This scientific exploration was followed by a close and practical look at a range of actual pests and predators, drawing on the expertise of Jessica Page. The microscopes were out and the questions flowed.
Select a plant community
The final session of the day focused on a plant community nominated by the group. This was Lucerne, a crop planted by or to be planted by a number of participants. This was a ‘hands on’ session, drawing on the knowledge and experience of participants, as well as the expertise of the presenters.
List known pests
The session proceeded with participants being asked to list known pests for Lucerne (e.g. pests: Red Legged Earth Mite, Lucerne Flea, Slugs, White Fringe Weevil, Aphids).
List known predators
From our earlier examination of pests & predators, the group was then able to list the known local predators (Beneficial: Predatory. mite, Predatory beetles, Predatory 'indigenous earwigs' (not the 'introduced earwigs' that cluster in great numbers), Snout mite, Carabid beetles, Lady Birds, Brown Lacewing, Wasps, Hover Flies).
As a group we were then asked to nominate the ‘cultural controls’, which we could implement as producers, such as: rotating crops, dry planting, timely planting, getting rid of Cape Weed that harbours so many pests, hard grazing at scheduled times; providing soil structure for predators, stubble retention so as to provide predators with habitat and so on.
Selective use of chemicals - if necessary
This IPM approach which emphasises the integration of biological controls, cultural controls, chemical controls along with regular monitoring of a crop, can readily be compared with the more usual approach where an annual insecticide spray such as ‘Timerite’ might be sought as the overall solution to a pest infestation of a Lucerne crop. In our IPM workshop we decided that for our Lucerne context, chemicals would be seen as part of the solution only, with ‘seed dressing’ of Lucerne before it is sown being a key, if moderation showed that pests were present.
In this way participants came to understand that an IPM approach, with each component being considered in turn (Crop, Pests, Biological Controls /Beneficial Predators, Cultural Controls and Chemical Controls, Monitoring), can lead to a significant reduction in chemical spraying and management of the crop in an holistic way.