Chemical compatibility testing of the entomopathogenic fungus Lecanicillium muscarium to control Bemisia tabaci in glasshouse environment

The potential for using the entomopathogenic fungus Lecanicillium muscarium to control the sweetpotato whitefly, Bemisia tabaci has been well established in previous studies under both laboratory and glasshouse conditions. In the current study, five chemicals were assessed for their compatibility with L. muscarium for control of B. tabaci under glasshouse conditions. On treatments following the sequential application of chemical product and fungus high mortality of second instar larvae was obtained (the known most susceptible B. tabaci life-stage to fungal infection). Sequential treatment of Savona and Certis spraying oil with L. muscarium produced 95 % and 96 % larval mortality, respectively. Commercially, unacceptable poinsettia foliage damage was recorded seven days post application of Agri-50E. Other plant foliage may prove more tolerant to this product. Incorporation of these chemicals with L. muscarium into integrated control programmes for B. tabaci control in glasshouses is discussed. Further information has been added to the knowledge base for the combined use of chemicals and fungi for the control of B. tabaci.