Insect pathogenic fungi and bed bugs: behaviour, horizontal transfer and the potential contribution to IPM solutions

Area of Science:

• Entomology
• Pest Management
• Microbial Control

Background:

• Bed bug infestations are a growing global concern, necessitating novel control methods.
• Insect pathogenic fungi offer a promising avenue for integrated pest management (IPM) strategies.

Purpose of the Study:

• To evaluate the efficacy of three insect pathogenic fungi against the common bed bug, Cimex lectularius.
• To investigate the virulence, formulation effects, and transmission dynamics of effective fungal agents.

Main Methods:

• Laboratory bioassays were conducted using Isaria fumosoroseus, Lecanicillium muscarium, and Beauveria bassiana against bed bugs.
• Virulence, dose-dependency, formulation effects (oil-based), and horizontal transfer were assessed in arena bioassays.
• Bed bug behavior, including activity patterns and response to CO2, infection, and aggregation, was observed.

Main Results:

• Only Beauveria bassiana demonstrated significant virulence against bed bugs, with efficacy dependent on dose and formulation.
• A 2% B. bassiana oil formulation facilitated horizontal transfer, increasing mortality, primarily between adult bed bugs.
• Increased fungal dose or CO2 levels did not enhance mortality; higher infection levels increased bed bug movement, potentially hindering transfer.

Conclusions:

• Beauveria bassiana is a viable biological control agent for bed bugs, capable of self-dissemination within a population.
• Fungal bio-pesticides, particularly B. bassiana, warrant further investigation as a component of sustainable bed bug management programs.