Dr Thomas Heddle1, Dr Kym Perry1, Dr David Logan1,2, Dr Kate Muirhead1,2

1University Of Adelaide, Urrbrae, Australia, 2South Australian Research and Development Institute, Urrbrae, Australia

Biography:

Dr. Thomas Heddle completed his PhD at the University of New England in early 2024. He has since moved on to the University of Adelaide where he is now working on a project dedicated the slugs in agricultural systems. Prior to commencing his PhD, Dr. Heddle worked as an agricultural entomologist for the South Australian Research and Development Institute (SARDI).

Abstract:

The black keeled slug, Milax gagates (Stylommatophora: Milacidae, Draparnaud, 1801), is a significant agricultural pest across the grain growing region of Australia. It feeds on seeds, young cotyledons, and leaves of canola, causing significant patches of failed establishment within paddocks. The biology and ecology of this subterranean species is poorly studied, with limited research conducted internationally and insubstantial studies in Australia. A new Grains Research Development Corporation (GRDC) project aims to increase the current knowledge of this pest species with field and laboratory studies. Slugs are being surveyed at 30 field sites across WA, NSW, VIC, and SA in the southern and western Australian grain growing regions. Limited rainfall in some regions has had an impact on detection of slugs. By mid-June 2024, only 1027 slugs have been collected, of which M. gagates accounts for 27% of the sample. Laboratory studies on the life history traits suggest that M. gagates aggregates at soil temperatures of 14-19°C, though this requires further investigation. Egg clutches laid by M. gagates are in the range of 10-20 eggs per clutch and are laid approximately 10-20 mm below the soil surface. Further studies will investigate soil moisture preferences for activity and egg laying, and influence of temperature on growth rates and activity… Understanding the biology of this pest will improve the management strategies currently used for this species.