Molecular markers for rapid identification of Liriomyza pests

Ms Tracey Bjorksten, Mr Peter Ridland (funded by ACIAR)

The highly polyphagous pest leafminers Liriomyza huidobrensis (Blanchard), Liriomyza sativae (Blanchard) and Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) have spread into South East Asiaand Oceania, and are likely to reach Australiain the near future. Liriomyza huidobrensis was first recorded in Indonesiain 1994, and the economic impact of this pest has been severe, with substantial losses reported in potato, celery,cucumber, spinach, snap bean, snow peas, red bean, shallot, faba bean and tomato. L. sativae has also become a serious pest in Indonesia, particularly in lowland regions.

Over the past three years CESAR has been part of a collaborative project with DPI Victoria, CSIRO and a number of Indonesian institutions, aiming to develop effective control measures for Liriomyza pests in Indonesia, and prepare for their arrival in Australia. In past years CESAR has been involved in identifying Australian parasitoid species and assessing the suitability of the dominant species for integration with chemical controls and use in augmentation or inundation programs. In 2004 the focus has been on developing molecular markers to enable rapid identification of Liriomyza species, to distinguish the three major pest species from each other and from non-pest Liriomyza species. Four restriction endonucleases have been identified which cleave a portion of the mitochondrial COI gene, providing unique RFLP profiles for nine species of leafminers, including 8 Liriomyza species and one Chromatomyia species. This method enables species identification within 24 hours of obtaining samples.