Soil-dwelling insect pests may cause considerable damage to crops worldwide, and their belowground lifestyle makes them hard to control. Amongst the most promising control agents for subterranean pests are soilborne entomopathogenic fungi (EPF) such as Metarhizium brunneum. Albeit EPF can be highly pathogenic to their target pest species under laboratory conditions, their efficacy in the field is often limited due to adverse environmental conditions. Here, we test for the first time if the efficacy of EPF can be improved when they are augmented with trap crops. In a field experiment, the M. brunneum strain ART2825 was combined with a trap crops mixture of six plant species and evaluated for its control effect of wireworms (Coleoptera: Elateridae). When both were combined in the main crop, potato damage was lowered on average by 42.5% and wireworm abundance by 50.8%. Single application of trap crops or EPF lowered damage/pest abundance only by 29.9%/15.89% and 34.7%/4.77%, respectively. Importantly, the strength of the synergistic pest control effect between trap crops and EPF increased disproportionately with increasing wireworm abundance. However, DNA-based gut content analysis showed that wireworms' feeding preferences were not shifting toward the trap crops. Our findings demonstrate that combining trap crops with EPF improves the efficacy of the latter and leads to a synergistic control effect which magnifies with increasing wireworm abundance. Hence, the synergistic effect of EPF and trap crops might be a promising control strategy for soil-dwelling pests in general and significantly improve our abilities to manage soil pests environmentally friendly.

Mosquitoes around the world spread diseases like malaria, dengue, zika, lymphatic filariasis and arboviruses, which are dangerous to human health and the economy. Eventually, mosquitoes develop resistance to synthetic chemical insecticides and, moreover, these insecticides have adverse environmental impacts, accumulating in soils and in the food chain. So, researchers are searching for better vector control tools from biological sources such as plants, bacteria, fungi, viruses and other predators. Eco-friendly methods that use entomopathogenic fungi to reduce vector-borne disease burdens are becoming more popular because they are selective and safe for the environment. Based on existing literature, several microbial agents show potential for the biocontrol of mosquitoes. With advances in genetic recombination and transformation techniques, in the ongoing battle against insecticide-resistant mosquitoes, genetically engineered fungal biopesticides represent a cutting-edge solution. These biopesticides are the result of novel genetic changes that improve the ability of fungi to target and kill mosquitoes. These fungi can effectively combat mosquito populations by introducing genes that produce insecticidal proteins or toxins. This method has several advantages, including a lower environmental impact, because the fungi are highly specific to mosquitoes and are harmless to non-target organisms. It also helps to reduce the problem of insecticide resistance because the fungi have a unique mode of action. These biopesticides hold great promise for reducing mosquito-borne diseases while minimizing environmental damage and combating resistance. This review article discusses various entomopathogenic fungal pathogens that can act as biocontrol agents and their mode of action against mosquitoes. We discus recent advances in entomopathogenic fungi-secreted effector molecules for suppressing host immunity and progress in the development of transgenic mosquito-killing fungi.

The indigenous soil-dwelling scale insect, Margarodes prieskaensis, can severely damage and even kill grapevines in the northern grape-growing regions of South Africa. There are no registered means of control, and soil applications of insecticides raise environmental concerns. Using local isolates of entomopathogenic fungi (EPF) that are better adapted to local conditions to target female margarodes could add a valuable biocontrol component to an integrated management strategy. The objective of this research was to evaluate the efficacy of a local isolate of Metarhizium pinghaense against M. prieskaensis females under field conditions. Dry conidia suspended in water and 0.05% v/v Tween 20, applied as a soil drench, achieved 19.1% and 17.7% infection of margarode females in the Northern Cape and Limpopo, respectively, in 2021. Conidia stored in canola oil, suspended in water and 0.05% v/v Tween 20 and applied as a soil drench achieved infection rates of 38.5% and 62.8%, respectively, at the same sites in 2022. These results confirm the importance of formulating conidia for protection against adverse environmental conditions to improve EPF efficacy in the field. This study is the first to demonstrate the efficacy of M. pinghaense against margarode females at the soil surface and confirms the potential of this EPF for the biological control of margarodes.