The Response of the Red Morph of the Tobacco Aphid, Myzus Persicae Nicotianae, to Insecticides Applied under Laboratory and Field Conditions

The tobacco aphid, Myzus persicae nicotianae is aneconomically important pest of tobacco, causing extensiveyield losses especially as it is an important host of numerousviruses and the sudden shift from the green morph to the redmorph is of concern as reports of insecticide resistance arecommon in this morph. The efficacy of several insecticideswas studied, both in the laboratory and in the field, to establishthe pest status of the red coloured morph of the tobacco aphidwith respect to resistance build up. The laboratory testsconfirmed that resistance could be of concern inMonocrotophos only and the field work appeared to showsome build up of resistance additionally in Aldicarb. Theresults point at a need for continued monitoring as well as useof rotations in chemical use in order to reduce the chance ofresistance build up.