During the growing season of 2003/04 a new aphid was found in lettuce crops in Tasmania.
This was the first Australian record of the Currant Lettuce Aphid, Nasonovia ribis-nigri.
This aphid is a pest of lettuce in New Zealand, North America and Europe.
It has been responsible for large yield losses because it lives deep inside the head of maturing lettuces secure from foliar insecticides.
It is not secure from systemic insecticides or predators such as brown lacewing, ladybirds and hoverflies.
The Australian vegetable industry is greatly concerned about the impact that this pest may have on lettuce crops. Their strategic plan to help combat the perceived impact of this pest included development of resistant lettuce varieties and high rates of imidacloprid insecticide as a seedling drench.
Many growers have adopted the practice of drenching seedlings just prior to planting with imidacloprid.
Imidacloprid is toxic to a broad range of insects but not caterpillars which are a major pest of lettuce.
If predators are impaired after eating poisoned aphids they are not available to complement the soft insecticides that are increasingly used for caterpillar control or to restrain other pests for which no selective insecticides are available.
This project sought to :
This project has demonstrated to growers and entomologists that there is a viable alternative to high rates of Confidor drenching on seedlings to control lettuce aphid in Australia.
Dr Paul Horne and Jessica Page from IPM Technologies P/L provided key professional knowledge and field experience in vegetable IPM to the research team and tuition to participants in field days.
The Department of Primary Industries, Water and Environment, Tasmania provided professional staff in kind, housed technical staff and provided the facilities and staff of the Forthside Vegetable Research and Demonstration Farm at normal research rates.
The NSW Department of Primary Industries provided professional staff – Dr Sandra McDougall, for project design and field events and access to the Lettuce Leaf newsletter.
This project was supported by a loan of planting equipment from Bovill Brothers, access to the Forthside Research and Demonstration Farm belonging to DPIWE, Tasmania, and access to Bovill Brothers’ Farms.
Horticulture Australia Limited provided funds for crop production, technical staff and travel for professional staff for this project.through The National Vegetable R&D Levy.
The Australian Government provides matched funding for all HAL’s R&D activities.