Pathogenicity of Beauveria bassiana to Atta sexdens rubropilosa (Hymenoptera: Formicidae) in laboratory conditions

Abstract

This research, under laboratory condition, evaluated the efficiency of different strains of entomopatogenic fungus Beauveria bassiana to control leaf-cutting ant Atta sexdens rubropilosa. Soldiers and workers were inoculated with suspensions containing 1.0x107, 1.0x108, 1.0x109 and 1.0x1010 con mL-1 and maintained in B.O.D, at 25±1°C, 70% RH and 12 hours of photophase, without food. The mortality was evaluated daily, with 15 days after inoculation. Experimental design was entirely random. The sporulation data were submitted to the analysis of variance and the LT50 values (in days) were obtained through the Probit analysis. All strains of B. bassiana were pathogenic, being workers more susceptible than soldiers. The strains IBCB 21 and IBCB 07 caused high percentages of confirmed mortality showing potential for use in the control of A. sexdens rubropilosa. Strain IBCB 21 was more virulent for workers, whereas isolated IBCB 07 was more virulent for soldiers. Both isolates presented no significant difference among tested concentrations.

Leaf-cutting ant species (Hymenoptera: Formicidae, Myrmicinae) in three agrosystems and the attractiveness of a natural bait to Atta laevigata’s biocontrol

“…The research occurred in both: 1. laboratory: bait preparation and evaluation of bait quality; 2. field: evaluation of bait acceptance and carrying of different concentration of fungi conidia incorporated in the baits. So, this research can be qualified as qualitative and quantitative (see Alves 1988;Loureiro et al 2022aLoureiro et al , 2022b.…”

“…The prospecting for non-polluting methods aimed at managing populations of leaf-cutter ant species, which have pest status in agrosilvipastoral systems is of paramount importance. Techniques that use physical barriers to protect trees and shrubs, have shown to be more promising (Jiménez et al, 2022), as well as the population suppression methods with biological weapons, especially entomopathogenic fungi (Loureiro et al, 2022a(Loureiro et al, , 2022b. The coexistence with leaf-cutting ant species should be sought, in order to enable the production of food free of pesticides; without major damage to rural producers, avoiding the local extinction of Attini species, because that last mission, is a task that is not only ecologically undesirable, but also, probably, impossible.…”

“…In the laboratory, isolates of the entomopathogenic fungus B. bassiana caused significant mortality for A. sexdens, with workers being more susceptible than soldiers. The isolate IBCB 21 also caused high percentages of confirmed mortality, being recommended for use in the biological control of leaf-cutting ants (Loureiro et al, 2022a). Loureiro et al (2022b) tested five isolates of the entomopathogenic fungus M. anisopliae against leaf-cutting ant adults.…”

Alginate-kaolinite beads incorporated with agrochemicals: new baits for leaf-cutting ants control

“…One biological agent that shows toxicity to ants is the Beauveria bassiana fungus, which is commercially available and widely used in agriculture and forestry (Li et al 2011). It has been extensively studied, showing prospects for future success in ant management (Cantú-Ruiz et al 2017;Folgarait et al 2020;Loureiro et al 2022). The success of using B. bassiana may be true because it has been observed that there are isolates of B. bassiana that cause mortality of 87% of A. sexdens workers after 4 days of application (Loureiro et al 2005).…”