Production and survival of eggs of the cattle tick Boophilus microplus (Canestrini) (Acarina: Ixodidae) in the wet and dry tropics of north Queensland

Monthly observations were made on egg production and egg survival of the cattle tick Boophilus microplus , at five sites in northern Queensland from August 1978 to July 1980. Egg production was close to the potential except in the hot, dry season in the drier sites and a model was fitted to explain the data. The main factors that reduced egg production were maximum soil temperature greater than 33.6°C, minimum soil temperature less than 17.6°C, and soil moisture less than 0.26 water-holding capacity when the soil maximum temperature was greater than 37.2°C. The model explains 61% of the variation in egg production from an independent set of data from southern Queensland. Analysis of egg viability at the time of retrieval from pasture indicated that the most important variables reducing viability were maximum soil temperature greater than 25.4°C, minimum soil temperature less than 16.9°C, soil moisture below 0.21 water-holding capacity, the sum of degree-days less than 3.95 per day and stress carried over from the egg production phase.