## 2 Host Diversity for _Cordyceps militaris_ Cultivation
Furthermore, substrates such as rice and wheat bran, along with plant-based options like soybean and potato dextrose, are commonly used due to their availability and cost-effectiveness, though they generally result in lower-quality bioactive compounds compared to insect hosts. This disparity is mainly attributed to differences in nutrient profiles essential for optimizing fungal metabolism. The choice of host species not only impacts the yield of bioactive compounds but also affects the quality and consistency of _C. militaris_ products. For example, silkworm pupae are a preferred host due to their nutrient-rich profile, which enhances the production of cordycepin and polysaccharides, compounds known for their anti-inflammatory and immune-boosting properties [44]. In contrast, other hosts like cicadas and beetles present different advantages and challenges. Cicadas are effective in supporting high-quality production, whereas beetles, due to their tougher exoskeletons, may yield lower levels of cordycepin but could produce unique peptides or secondary metabolites [49]. Furthermore, substrates such as rice and wheat bran, along with plant-based options like soybean and potato dextrose, are commonly used due to their availability and cost-effectiveness, though they generally result in lower-quality bioactive compounds compared to insect hosts. Thisdisparity is mainly attributed to differences in nutrient profiles essential for optimizing fungal metabolism. The selection of analytical methods, such as high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy, is critical for evaluating how host species influence the concentration of bioactive metabolites in _C. militaris_. While HPLC is widely employed for its precision in quantifying cordycepin, it is essential to recognize its limitations, including the need for extensive sample preparation and the potential for compound degradation during analysis. Furthermore, HPLC may not be ideal for detecting compounds at very low concentrations or within highly complex mixtures. To address these limitations, complementary techniques like GC-MS and NMR offer broader analytical capabilities, such as identifying a wider array of metabolites and providing detailed structural information about these compounds. These methods are particularly valuable for obtaining a comprehensive metabolomic profile of _C. militaris_ cultivated on various hosts, thereby providing deeper insights into how different hosts affect metabolite production [43]. Variations in cordycepin production among different host species can be attributed to several key factors, including the nutrient profile of the host, the physiological state of the host at the time of inoculation, and the genetic strain of _C. militaris_ used. For instance, Lepidoptera hosts, which are rich in lipids and proteins, provide essential precursors for the synthesis of bioactive compounds. This nutrient-rich environment stimulates higher metabolic activity in _C. militaris_, leading to increased cordycepin production. Additionally, the interaction between fungal genetics and the host's biochemical environment plays a significant role in optimizing bioactive compound synthesis. Certain hosts, like Lepidoptera larvae, yield higher levels of cordycepin due to their abundant lipid and protein content, which are crucial for the biosynthesis of this compound. The nutritional composition of the host directly influences the metabolic pathways in _C. militaris_, thereby enhancing cordycepin production. Furthermore, the host's immune response to fungal infection can trigger the synthesis of secondary metabolites as a defense mechanism by the fungus, further boosting cordycepin production [53]. These factors underscore the importance of selecting host species that naturally enhance cordycepin production, enabling the optimization of cultivation practices to achieve higher yields, reduce costs, and improve the consistency of medicinal products derived from _C. militaris_.