Pests and disease
The main use for Dimethoate on olives is for the control of Olive Lace Bug (OLB).
Permit extended for Dimethoate use on olives This year’s prolific rains were a welcome relief for growers in many regions, bringing much needed water to groves across New South Wales and Victoria. Unfortunately, however, the moisture also increased the incidence of pest and disease issues like Olive Lace Bug (OLB), particularly in regions like the Hunter where OLB was already a problem in early March. So it was positive news in April when the Australian Pesticides and Veterinary Medicines Authority (APVMA) re-issued and extended the Chemical Permit 13999 (Version 7) for Dimethoate for use on olives. The permit was renewed following submission of outstanding residue data generated from the Hort Innovation project MT18018 trials, as per the requirements of the APVMA chemical review, with a new expiry date of 31 March 2022. Note: the permit allows Dimethoate use only on trees/fruit used for olive oil production and not for table olive production.
Dimethoate usage
Dimethoate is a broad-spectrum systemic organophosphorus insecticide and acaricide used for a wide range of pests on fruit, vegetables, other crops and pastures.
Fast facts: Olive Lace Bug Froggattia olivinia
Identifiers: adults 3mm. Adults are mottled brown. Biology and damage: Australian native species recorded in NSW, QLD, VIC, SA, WA and most recently TAS. Two to four generations per year. Spiny nymphs occur in clusters on undersides of leaves; the first generation commonly emerge from leaves in spring. All stages attack leaves with piercing mouthparts, causing yellow spotting. Black tar spots occur on undersides of leaves. Leaf drop and twig dieback may occur in severe infestations. Natural enemies: few recorded. Green lacewings have been observed predating on lace bug nymphs and spiders on
AOA Agri-Chemical Permits Co-ordinator Peter McFarlane said the main use for Dimethoate on olives is for the control of Olive Lace Bug (OLB), Froggattia olivinia, which is a serious Australian native pest of olives. The permit also allows use for Green Vegetable Bug and Rutherglen Bug, however these are rarely reported as problems in olives. McFarlane said that Dimethoate is an ‘old chemistry’ option among a growing suite of approved ‘new chemistry’ control options for OLB, so its predicted eventual demise will not be problematic for industry. The range includes six additional chemicals with current APVMA permits for olives, two of which have organic approval, with another pending. ‘Natural’ options including horticultural oils and biological insects add further control choice. The project OL17001 An Integrated Pest and Disease Management Extension program for the Olive Industry was funded by Hort Innovation using the olive research and development levy, co-investment from the Australian Olive Association and Western Sydney University and funds from the Australian Government.
adults; birds may also be predators. The native green lacewing Mallada signatais is commercially available and has been released into some groves. Management: if required, lace bug can be targeted by judicious use of insecticides. Several, including pyrethrum and potassium soap, may be organically acceptable inputs. Sprays need to be targeted at young nymphal stages, so monitoring for nymphal hatch, especially of the first generation in spring, is important. Opening up tree canopies exposes nymphs to greater likelihood of dehydration, and also to access by sprays. Stressed trees are more susceptible to lace bug attack, so maintaining healthy
trees greatly assists in pest management. IPDM information flyers This information is sourced from one of a series of flyers produced as outputs of the Hort Innovation-funded project OL17001 An Integrated Pest and Disease Management Extension program for the Olive Industry. Topics of other flyers include: Black scale, Olive lace bug, Weevils, Anthracnose, Peacock spot, Cercospora leaf mould, Olive wood rots and dieback, Exotic pests and diseases, and Current chemical options for key pests and diseases. All are available from the OliveBiz website – www.olivebiz.com.au under the Projects dropdown - IPDM outputs.
Issue 120 • June 2021 • Australian & New Zealand Olivegrower & Processor • 47
