A US viewpoint on invasive pests
There were many interesting presentations and follow-up discussions, information from which will be incorporated in future articles, but two other excellent keynote addresses deserve mention. The topic of the talk by Prof. Michael Parrella, University of California, Davis, was ‘Proactive Development of IPM Programs for Invasive Pests’. If I may paraphrase Prof. Parrella, what the US authorities have been doing in regard to invasive pests for many years is “papering over the cracks”, at huge cost but achieving little improvement in actually managing those pests, let alone eradicating them. What is needed is a systems approach to IPM for invasive species and an invasive species policy, but this is very difficult to achieve. Quarantine directives in California affect the greenhouse and ornamental industries rather than field crops. The National Invasive Species Council has responsibility at a national level for invasive pests but the reality is that while its activities and directives look good on paper the war is being lost. Similarly, the Invasive Species Council of California is focussed on eradication rather than prevention. Emergency programs for the same pest go on year after year and soak up personnel and money to little end except to tread water. Many of the quarantine pests in reality are resident and it is just not possible to eradicate them, but authorities are stuck in the same groove. The action has more to do with keeping trade routes open or conducting a public-relations exercise than managing the problem. Mike would like to see a change in thinking based on good science, and is part of a UC Davis team examining alternative approaches (Feb/March 2012 meeting at UC Davis coming up). One of the side-effects of an overbearing eradication focus has been that to conform to protocols, a heavy reliance is placed on pesticides to ‘eradicate’ the pest.
The huge cost burden falls on the horticultural industry. These protocols serve mostly to undermine and sideline IPM programs, which might have better ‘managed’ the reality of dealing with an established pest. This is not to say that eradication should not be considered for new invasive pests, but decisions should be based on scientific reality and limited resources directed more to prevention and management.
A European approach to a new invasive pest
Dr Rob Jacobson, RJC Ltd, Bramham, Yorkshire, presented just about the right counterbalance for the current US approach to invasive pests in his talk ‘Tuta absoluta: A realistic approach to IPM?’ We wrote about this new invasive lepidopteran pest in PH&G Issue 108, Sep/Oct 2009. Since then it has continued to spread to adjoining countries, but a major effort by European IPM specialists is making significant inroads in managing the problem within a total crop IPM program. It was clearly not an option for eradication in Europe but there is every reason to prevent it from arriving in Australia, particularly because we do not have the personnel and biocontrol specialists able to control it without pesticides. A cooperative scientific approach was taken very early on, with teams from various countries studying different aspects of its life-cycle, alternative crop and weed hosts, pheromones and possible control options. The approach was conducted in four phases. The first was to suppress the initial population growth with screening, mass trapping, mating disruption, biocontrol-compatible pesticides, physical controls and available generalist predators. In the second phase, heavier-duty pesticides and entomopathogenic nematodes were evaluated. In the third phase, management of two generalist predatory bugs was necessary to prevent plant damage in tomatoes, and finally, in the fourth phase, methods for clean-up of an infestation between crops were developed. With this it has been possible to reduce damage to a manageable level. Given its potential importance to Australia, we plan to provide an update to managing this pest in a future issue.
Field study tours
The first field study tour went to VHB Herbs, Donaldson’s Nursery (strawberries), Madestein UK Ltd (lettuce), Roundstone Newlands near Chichester (bedding and pot plants), Walberton Nursery, Arundel (ornamental shrubs and pot plants) and Becker Underwood Ltd, Littlehampton (entomopathogenic nematodes). Unfortunately, we were not able to split ourselves between three buses going to different operations but all would have been of interest. The second tour went to Double H Nurseries Ltd, New Milton (pot plants), a handy drop-off point for supper at the Domus, adjacent to The Beaulieu Motor Museum, and a 1am return to base for two tired but enthused travellers. Again, more details on some of these tours in the next issue.
About the authors
Stephen Goodwin and Marilyn Steiner are IPM consultants trading as Biocontrol Solutions at Mangrove Mountain.
Email: sgoodwin.msteiner@gmail.com
