Susceptibility of non-target invertebrates to Brazilian microbial pest control agents

Abstract

Microbial pest control agents or entomopathogens have been considered an interesting alternative to use instead of chemical insecticides. Knowledge of ecotoxicity data is very important to predict the hazard of any product released in the environment and subsidize the regulation of these products by governmental agencies. In the present study four new Brazilian strains of Bacillus and one fungus were tested to evaluate their acute toxicity to the microcrustacean Daphnia similis, the snail Biomphalaria glabrata and the dung beetle Digitonthophagus gazella. The microcrustaceans and the snails were exposed to entomopathogens in synthetic softwater and the beetles were exposed directly in cattle dung. Obtained data reveal low susceptibility of the non-target species to tested microorganisms, with lethal concentrations being observed only at much higher concentrations than that effective against target insects. These results show that the tested strains are selective in their action mode and seem to be non-hazardous to non-target species.

Evaluating the Elimination of Brazilian Entomopathogenic Bacillus by Non-target Aquatic Species: An Experimental Study

“…The elimination rate is an important parameter and needs to be included in microbial toxicity guidelines because this evaluation with entomopathogens is similar to the bioaccumulation factor for chemicals. As shown in other publications, Bacillus thuringiensis and B. sphaericus in the concentration of 10 6 spores/mL were not lethal to Biomphalaria glabrata (Oliveira-Filho et al 2011) or to the fish Danio rerio (Grisolia et al 2009). In the present study it was observed that the tested entomopathogens were not acutely toxic to Hyphessobrycon eques either.…”

“…Microbial pesticides have been presented as an alternative to chemical pesticides. Several studies have shown significantly higher efficiency and selectivity of Brazilian entomopathogens, which generate a lower environmental impact (Oliveira-Filho 2005;Grisolia et al 2009;Oliveira-Filho et al 2011). The use of microbial products for mosquito control has also been of great importance to developing countries, where the return of diseases transmitted by mosquitoes has become a public health problem in recent years (Sabbatini et al 2010).…”

Genotoxic evaluation in Oreochromis niloticus (Fish: Characidae) of recombinant spore–crystal complexes Cry1Ia, Cry10Aa and Cry1Ba6 from Bacillus thuringiensis

“…Reports in the literature have shown mortality of fish species Hyphessobrycon scholzei exposed to B. thuringiensis strain 344; however, the exposure concentration occurred at 1,0009 higher than that used in the field (Jonsson et al 2009). In contrast, B. thuringiensis did not cause any kind of toxic adverse effects to different fish species exposed to 1.3 and 1.7 9 10 10 spores (Johnson and McGaughey 1996) or up to 10 6 -10 7 spores/ml to freshwater invertebrates (Oliveira-Filho et al 2011).…”

The use of statistical tools in field testing of putative effects of genetically modified plants on nontarget organisms

“…(27). These authors studied the influence of pest control agents on nontarget invertebrates in soil.…”

“…; Oliveira‐Filho et al. ; Yamamori ). It is important to state that the experimental design (e.g., the field lay‐out, sample size, sampling method, number of (sub) samples, and replicates, and the way in which the treatments are randomized over the experimental units) defines how the data should be analyzed.…”