Potency of Combinations of Bacillus thuringiensis and Chemical Insecticides on Spodoptera littoralis (Lepidoptera: Noctuidae)

In Vivo Study on Combined Toxicity of <I>Metarhizium anisopliae</I> (Deuteromycotina: Hyphomycetes) Strain ESC-1 with Sublethal Doses of Chlorpyrifos, Propetamphos, and Cyfluthrin Against German Cockroach (Dictyoptera: Blattellidae)

“…The additive effects of entomopathogens and insecticides were reported by Hiromori and Nishigaki (1998), whereas synergistic effects were also reported by Kaakeh et al (1997) for controlling German cockroaches with imidacloprid ϩ M. anisopliae, and Quintela and McCoy (1997) for controlling the root weevil Diaprepes abbreviatus (L.) with imidacloprid ϩ M. anisopliae. Results observed in our study and other studies (Anderson and Roberts 1983, Salama et al 1984, Charnley 1989, Sanyang and Van Emden 1996, Hiromori and Nishigaki 1998 clearly indicate that entomopathogens are compatible with some insecticides and microbial agents. Studies of insecticides plus entomopathogens further demonstrate that integrating insecticides and entomopathogens is an option with signiÞcant impact on pest mortality, and such an integrated approach will increase pest mortality as well as reduce the lethal time to cause the equivalent effect in comparison to entomopathogens alone.…”

“…Because the commercial formulation was used, the sublethal doses (starting at 1/10 of the label rate) were selected from the Þeld-recommended doses and insecticides were suspended in water as recommended by the manufactures (Tedders 1981, Samuels et al 1989, Li and Holdom 1994. This experimental protocol of mixing commercial formulation with water or surfactant plus water was also used by other researchers (Anderson and Roberts 1983, Salama et al 1984, Anderson et al 1989, Quintela and McCoy 1997. In contrast, if technical grade material had been used then it would have been essential to produce the probit line with 95% CL and the sublethal doses could have been selected from the probit analysis for subsequent bioassays.…”

“…where O i was the proportional mortality caused by insecticides and O m was the proportional mortality caused by M. anisopliae (Richter and Fuxa 1984, Salama et al 1984, Morris et al 1994). The expected value was then converted into percentage mortality.…”

“…One of the options for improving the efÞcacy of the entomopathogenic fungi is to incorporate the fungal pathogens with sublethal doses of insecticides (Anderson and Roberts 1983, Salama et al 1984, Charnley 1989, Sanyang and Van Emden 1996, Hiromori and Nishigaki 1998. Data from in vivo compatibility studies have indicated that M. anisopliae and insecticides are compatible, and their combination can have a synergistic, antagonistic (Salama et al 1984;Kaakeh et al 1997;McCoy 1997, 1998) or additive effect (Salama et al 1984, Anderson et al 1989. McCoy (1990) stated that physiological starvation or nutritional deÞciency in the M. anisopliae infected host is one of the mode of action caused by this fungus.…”

Pesticide Mixtures

“…Pesticide mixtures associated with pyrethroid-based insecticides have been shown to potentiate the activity of the microbial, Bacillus thuringiensis Berliner subsp. galleriae against the cotton leafworm, Spodoptera littoralis (Boisduval) (Salma et al 1984), and B. thuringiensis subsp. kurstaki against the fall armyworm, S. frugiperda (J. E. Smith) (Habib and Garcia 1981).…”