Virulence and transgenerational effects of Metarhizium anisopliae on Oxycarenus hyalinipennis

Insect pests cause major yield losses to Gossypium hirsutum, often requiring the use of chemical insecticides. To avoid human health, environmental and resistance problems, entomopathogenic fungi (EPF) can be used to control insect pests. In our study, the pathogenicity of Metarhizium anisopliae to Oxycarenus hyalinipennis was determined by the immersion method. Furthermore, the sublethal and lethal effects of M. anisopliae on the biological parameters of O. hyalinipennis were investigated by age-stage, two-sex life table software.

M. anisopliae infection was lethal to the fourth instar of O. hyalinipennis with LC₅₀ values of 8.84 × 10⁴ spores mL^-1 . The sublethal and lethal concentrations of M. anisopliae not only affected the parental generation (F₀ ) but also the demographic parameters of the offspring of the filial generation (F₁ ). Transgenerational results of F₁ infected with M. anisopliae showed decreased net reproductive rate (R₀ ), intrinsic rate of increase (r) and mean generation time (T) compared to those of the control group. The larval developmental duration significantly decreased to 15.52 and 19.02 days in the LC₅₀ and LC₂₀ groups, respectively, compared to 21.08 days in the control group. There was a noteworthy decline in mean fecundity in the LC₅₀ and LC₂₀ groups, i.e., 16.0 and 20.96 eggs, compared to 33.26 eggs in the control group. Adult longevity was likewise considerably reduced in the LC₅₀ and LC₂₀ treated groups.

The study showed that M. anisopliae can have an enduring impact on the biological parameters of O. hyalinipennis, which may enhance its use in eco-friendly management programs. © 2023 Society of Chemical Industry.