Seasonal density fluctuations of the exotic ornate kangaroo tick, Amblyomma triguttatum triguttatum Koch, and its distribution on Yorke Peninsula, South Australia

The ornate kangaroo tick, Amblyomma triguttatum triguttatum, was recently recorded on southern Yorke Peninsula, South Australia. We examined seasonal fluctuations in A. triguttatum triguttatum life stages (adult, larva, and nymph) and its distribution on the peninsula. We used in situ CO2 traps and dragging cloths to determine monthly fluctuations in free-living ticks at four sites at Innes National Park from January to December 2006, and to determine the tick's distribution on wider Yorke Peninsula. At each site, 166 m2 of ground surface were directly sampled with cloths, representing 16 1-m2 CO2 stations and three 1-m-wide 50-m transects. Adult A. triguttatum triguttatum were present in January and February and from August to December, with a peak (n=54) occurring in November. Larvae were present from February to August, with their highest density (n=3067) detected in March. Nymphs were collected from January to April and from August to December, with the highest density (n=61) detected in September. Overall, A. triguttatum triguttatum numbers were highest in March when larvae peaked, and few ticks were detected in January (summer) or July (winter). Ticks occurred at several sites on southern Yorke Peninsula, supporting their invasive status.