Compatibility of the entomopathogenic fungus Lecanicillium muscarium and insecticides for eradication of sweetpotato whitefly, Bemisia tabaci

Abstract

The compatibility of the entomopathogenic fungus Lecanicillium muscarium and chemical insecticides used to control the second instar stages of the sweetpotato whitefly, Bemisia tabaci, was investigated. The effect on spore germination of direct exposure for 24 h to the insecticides imidacloprid, buprofezin, teflubenzuron and nicotine was determined. Only exposure to buprofezin was followed by acceptable spore germination. However, all chemicals significantly reduced spore germination when compared to a water control. Infectivity of L. muscarium in the presence of dry residues of buprofezin, teflubenzuron and nicotine (imidacloprid is a systemic pesticide) on foliage were also investigated. No significant detrimental effects on the level of control of B. tabaci was recorded when compared with fungi applied to residue free foliage on either tomato or verbena plants. Fungi in combination with imidacloprid gave higher B. tabaci mortality on verbena foliage compared to either teflubenzuron or nicotine and fungi combinations. Use of these chemical insecticides with L. muscarium in integrated control programmes for B. tabaci is discussed.

Leaf dipping as an environmental screening measure to test chemical efficacy against Bemisia tabaci on poinsettia plants

“…This study, using leaf dipping as a screening method (Buxton and Clarke, 1994;Buxton et al, 2008), investigated the potential of various low toxicity chemical and fungal products for their efficacy against various lifestages of B. tabaci. The collected information will be added to the knowledge base of potential chemicals already used against B. tabaci within IPM strategies in the United Kingdom (Buxton and Clarke, 1994;Cuthbertson et al, 2005a).…”

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

“…Further work could involve applying the fungus followed by insecticides at increasing time intervals to investigate potential protection of the fungus with increasing time before application of an insecticide. Testing for Agri-50E, which did produce a high level of B. tabaci mortality and which also has shown previously a high potential for direct mixing with L. muscarium (Cuthbertson et al, 2008a), phytotoxic effects on other plant species could prove useful in the development of IPM strategies.…”

“…The entomopathogenic fungus Lecanicillium muscarium has shown significant potential for incorporation into integrated pest management (IPM) programmes for the control of B. tabaci, where, second instar larvae have proven most susceptible to fungal infection . Lecanicillum muscarium has also shown potential for control of B. tabaci larvae in glasshouses on a range of plant hosts, including poinsettia Cuthbertson et al, 2008a;Down et al, 2009). Previous investigations into chemical insecticide compatibility with L. muscarium have found varying results.…”

Effect of photoperiod and host distribution on the horizontal transmission ofIsaria fumosorosea(Hypocreales: Cordycipitaceae) in greenhouse whitefly assessed using a novel model bioassay

“…Due to the inappropriate use of insecticides, environmental concerns and evolution of resistance to important insecticides, there is need for alternative methods to control whiteflies (Omer et al 1992;Sanderson & Rousch 1992;Bi & Toscano 2007). Entomopathogenic fungi are being developed as major components of integrated pest management programs for controlling T. vaporariorum and other whiteflies (Fransen 1993;Poprawski & Jones 2000;Meekes et al 2002;Vidal et al 2003;Cuthbertson & Walters 2005;Cuthbertson et al 2008). Most research using fungi for controlling aleyrodids has focused primarily on using Beauveria bassiana (Balsamo) Vuillemin, Lecanicillium muscarium (Petch) Zare & Gams and Aschersonia species; however, Isaria fumosorosea (=Paecilomyces fumosoroseus) Wize (Hypocreales: Cordycipitaceae), has also been shown to cause epizootics in whitefly populations on various host plants (Lacey et al 1995;Wraight et al 2000;Meekes et al 2000;Gökçe & Er 2005;Saito 2005;Alma et al 2007).…”