PestFacts Issue 10, 2019
In this issue
- Black Portuguese millipedes on the move after recent rain
- Summer management of pest snails
- Early Harvesting: the key to sustainable pea weevil management
- On the battlefield: tackling pesticide resistance head on
Black Portuguese millipedes on the move after recent rain
After recent rains, black Portuguese millipedes (PDF 941.2 KB), Ommatoiulus moreleti, activity has increased, with reports of movement occurring on the Eyre Peninsula and on the upper Yorke Peninsula.
Black Portuguese millipedes have also been reported as a contaminant in grain samples. As millipedes mainly active at night, grain contamination risk might be higher during night-time harvesting.
It is believed black Portuguese millipede numbers have increased in recent years due to increased stubble retention creating a favourable habitat. Portuguese millipedes feed mainly on herbaceous detritus. Laboratory trials found that when millipedes did feed on live plants, it was mostly lupin and lucerne, occasionally canola seedlings, but rarely other crops (Douglas et al 2017). It is not always clear why they switch from feeding on dead organic matter to live plants.
Preventative action is key to the control of Portuguese millipede as there are limited management options and no registered pesticides against them in broad acre crops. Reduce stubble retention and remove trash, especially in summer and early autumn, to minimise numbers in future.
Avoid planting lupin or lucerne where high numbers of millipedes are present. Sources of reports: Nigel Myers (Landmark Cummins), Chris Davey (YP Ag).
Josh Douglas, Sarina Macfadyen, Ary Hoffmann, Paul Umina, Crop Seedling Susceptibility to Armadillidium vulgare (Isopoda: Armadillidiidae) and Ommatoiulus moreletii (Diplopoda: Iulidae), Journal of Economic Entomology, Volume 110, Issue 6, December 2017, Pages 2679–2685, https://doi.org/10.1093/jee/tox275