Date Issued:2014-08-05


In 2010-2011 some 96% of the strains tested showed some level of neonicotinoid resistance (ie Actara-Cruiser or Shield) but that had fallen to 29% of cotton strains in season 2011-2012 and a similar 33% of cotton aphid strains in season 2012-2013. It is possible that neonicotinoid resistance will plateau at approximately 30% of populations tested. For the 2013-2014 season cotton aphid was particularly difficult to find although eight strains were eventually collected. This season cotton aphid will be additionally tested against sulfoxaflor (Transform) and spirotetramat (Movento) for resistance. During 2012-2013 two-spotted mite (TSM) was susceptible to diafenthiuron (Pegasus) only with all strains showing some degree of bifenthrin (Talstar) resistance and half the strains indicating some abamectin (Agrimec) resistance. The detection of propargite (Comite) resistance in 1 of the 4 strains tested is of concern because it is a mainstay product for mite control. TSM made resurgence during 2013-2014 with some thirteen strains collected (normally ca. 5). Despite ubiquitous and large thrips numbers reddened two-spotted mite hotspots were evident in some fields with mites requiring targeted sprays. Work has continued preparing for possible resistance in mirids and these past two seasons' baseline data was generated against clothianidin (Shield) and fipronil (Regent) and discriminating doses for resistance detection interpolated. For season 2013-2014 some growers thought fipronil (Regent) may not be working as reliably as before so samples were collected and for the first time are to be evaluated using molecular methodology for a fipronil (Regent) resistance causing gene

Show Full Details

This item appears in the following categories