Journal of Mosquito Research, 2024, Vol.14, No.5, 237-246 http://emtoscipublisher.com/index.php/jmr 238 This study systematically evaluates the effectiveness of various biological control agents against mosquitoes by assessing their impact on mosquito population dynamics, evaluating their role in reducing the transmission of mosquito-borne diseases, identifying the advantages and limitations of different control strategies, and providing recommendations for integrating these agents into comprehensive mosquito management programs, ultimately aiming to inform public health strategies and contribute to the development of more effective and sustainable mosquito control methods. 2 Types of Biological Control Agents 2.1 Microbial agents Microbial agents such as Bacillus thuringiensis israelensis (Bti) and Bacillus sphaericus (Bs) are widely used for mosquito control. These bacteria produce toxins that are lethal to mosquito larvae when ingested. Bti, for instance, has been shown to be effective in various environments, including mixed saltmarsh-mangrove systems, although its efficacy can be reduced by factors such as high mangrove canopy density (Johnson et al., 2020). Long-lasting formulations of Bti and Bs have been developed to extend their activity duration, which has proven effective in reducing malaria vector densities without significantly impacting non-target organisms (Derua et al., 2018). However, there are concerns about the potential indirect effects on food webs, particularly the reduction of chironomid populations, which are a key food source for many aquatic and terrestrial predators (Allgeier et al., 2019a; 2019b). 2.2 Predatory organisms Predatory organisms, including fish and invertebrates, play a significant role in controlling mosquito populations by preying on mosquito larvae. Fish species such as Gambusia affinis (mosquitofish) are commonly introduced into water bodies to consume mosquito larvae. Invertebrates like dragonfly larvae and certain beetles also contribute to reducing mosquito populations. The effectiveness of these predators can vary based on environmental conditions and the availability of alternative prey. For instance, the presence of dragonfly larvae has been shown to decrease the survival rates of newt larvae in Bti-treated environments due to increased intraguild predation (Allgeier et al., 2019a). 2.3 Parasitoids Parasitoids, including nematodes and fungi, are another group of biological control agents used against mosquitoes. These organisms infect and kill mosquito larvae or adults. For example, entomopathogenic fungi such as Beauveria bassiana and Metarhizium anisopliae have been studied for their potential to control mosquito populations. Combining parasitoids with other biocontrol agents, such as entomopathogenic microorganisms, can enhance their effectiveness. Studies have shown that certain combinations of parasitoids and microorganisms are compatible and can improve pest control outcomes (Koller et al., 2023). 2.4 Genetic control methods Genetic control methods involve altering the genetic makeup of mosquito populations to reduce their ability to reproduce or transmit diseases. One such method is the release of Wolbachia-infected mosquitoes, which can reduce the transmission of diseases like dengue and Zika by interfering with the reproductive capabilities of mosquitoes. Another approach is the Sterile Insect Technique (SIT), where sterile male mosquitoes are released to mate with wild females, resulting in no offspring. These methods have shown promise in reducing mosquito populations and disease transmission. For instance, the use of Wolbachia-infected mosquitoes has been effective in various field trials, demonstrating significant reductions in mosquito populations (Figure 1) (Silva-Filha et al., 2021). Silva-Filha et al. (2021) investigates the mode of action of Bacillus thuringiensis israelensis (Bti) toxins, specifically Cry and Cyt proteins, in controlling mosquito larvae. The research emphasizes the crucial role of toxin-receptor interactions and toxin oligomerization in the larval gut, which leads to cell lysis and ultimately larval death. The paper discusses the structural characteristics of Cry toxins, including their receptor-binding domains, and highlights the importance of cadherin (CAD) and Cyt1Aa in facilitating the oligomerization and
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