Experimental and Applied Acarology (2015) 65, 259-276

Garrick McDonald, Paul A. Umina, Sarina Macfadyen, Peter Mangano and Ary A. Hoffmann (2015)
Predicting the timing of first generation egg hatch for the pest redlegged earth mite Halotydeus destructor (Acari: Penthaleidae)
Experimental and Applied Acarology 65 (3), 259-276
Abstract: Integrated pest management in Australian winter grain crops is challenging, partly because the timing and severity of pest outbreaks cannot currently be predicted, and this often results in prophylactic applications of broad spectrum pesticides. We developed a simple model to predict the median emergence in autumn of pest populations of the redlegged earth mite, Halotydeus destructor, a major field crop and pasture pest in southern Australia. Previous data and observations suggest that rainfall and temperature are critical for post-diapause egg hatch. We evaluated seven models that combined rainfall and temperature thresholds derived using three approaches against previously recorded hatch dates and 2013 field records. The performance of the models varied between Western Australia and south-eastern Australian States. In Western Australia, the key attributes of the best fitting model were more than 5 mm rain followed by mean day temperatures of below 20.5 °C for 10 days. In south-eastern Australia, the most effective model involved a temperature threshold reduced to 16 °C. These regional differences may reflect adaptation of H. destructor in south-eastern Australia to varied and uncertain temperature and rainfall regimes of late summer and autumn, relative to the hot and dry Mediterranean-type climate in Western Australia. Field sampling in 2013 revealed a spread of early hatch dates in isolated patches of habitat, ahead of predicted paddock scale hatchings. These regional models should assist in monitoring and subsequent management of H. destructor at the paddock scale.
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Link to article at publishers website
Database assignments for author(s): Paul A. Umina, Ary A. Hoffmann, Sarina Macfadyen

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Halotydeus destructor		Australia (South+SE)
	Halotydeus destructor		Australia (Western)