Field Crop 2024, Vol.7, No.3, 182-190 http://cropscipublisher.com/index.php/fc 188 By employing a combination of insecticide rotation, IPM, and genetic approaches, it is possible to manage WCR resistance effectively and sustain maize yield. Continuous monitoring and adaptation of these strategies are essential to address the evolving resistance patterns in WCR populations. 8 Advances in Research and Technology 8.1 New insecticidal compounds Recent studies have highlighted the development and evaluation of new insecticidal compounds to manage the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte. For instance, research has shown that soil-applied insecticides such as tefluthrin and bifenthrin can effectively protect maize roots from WCR damage, although their efficacy is significantly reduced in populations exhibiting pyrethroid resistance (Souza et al., 2019). Additionally, the use of neonicotinoids like clothianidin has been found to significantly reduce WCR larval density and increase grain yield when applied as seed treatments (Ferracini et al., 2021). The exploration of alternative compounds, such as entomopathogenic nematodes, has also shown promise, with studies indicating that Heterorhabditis bacteriophora can be as effective as traditional insecticides like tefluthrin in controlling WCR larvae (Modic et al., 2020). 8.2 Precision agriculture and application techniques Advancements in precision agriculture have led to more targeted and efficient application techniques for insecticides. The integration of precision agriculture tools allows for the precise application of insecticides, reducing the overall amount used and minimizing environmental impact. For example, the use of soil conditioners in combination with entomopathogenic nematodes has been shown to enhance the effectiveness of biological control methods, providing a sustainable alternative to chemical insecticides (Modic et al., 2020). Additionally, the application of insecticides at sowing, either as seed treatments or in-furrow applications, has been demonstrated to significantly reduce WCR larval density and improve maize yield (Ferracini et al., 2021). 8.3 Monitoring and resistance detection Effective monitoring and early detection of resistance are crucial for managing WCR populations and mitigating the impact of resistance on maize yield. Studies have shown that field-evolved resistance to various insecticides, including pyrethroids and Bacillus thuringiensis (Bt) traits, is a significant challenge in WCR management (Gassmann et al., 2019; Meinke et al., 2021). Monitoring programs that assess WCR susceptibility to different insecticides can help in the timely detection of resistance and inform management strategies. For instance, laboratory dose-response bioassays have been used to confirm resistance levels and guide the selection of appropriate insecticides for field application1. Additionally, integrated pest management (IPM) approaches that combine chemical, biological, and cultural control methods are recommended to manage resistance and prolong the effectiveness of available insecticides (Meinke et al., 2021; Furlan et al., 2022). By leveraging these advances in research and technology, it is possible to develop more effective and sustainable strategies for managing WCR and protecting maize yield. 9 Challenges and Future Directions 9.1 Barriers to effective control The control of the Western Corn Rootworm (WCR) faces several significant barriers. One of the primary challenges is the development of resistance to various classes of insecticides, including pyrethroids, organophosphates, and carbamates, which has been documented over several decades (Souza et al., 2019; Meinke et al., 2021). This resistance reduces the efficacy of traditional chemical control methods, necessitating the development of new strategies. Additionally, the persistence of resistance even in the absence of selection pressure suggests minimal fitness costs associated with resistance traits, complicating management efforts (Meinke et al., 2021). Another barrier is the limited effectiveness of certain insecticides under field conditions, particularly in areas with high levels of resistance (Souza et al., 2019). Furthermore, the environmental impact and regulatory restrictions on the use of certain insecticides pose additional challenges to effective WCR management (Furlan et al., 2022).
RkJQdWJsaXNoZXIy MjQ4ODY0NQ==