Han Chiao-Jung, Hseu Zeng-Yei, Wu Po-Hui, Grillet Louis, Ko Chun-Han, Shelomi Matan
Department of Entomology, National Taiwan University, Taipei, Taiwan.
Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
Bot Stud. 2025 Aug 5;66(1):22. doi: 10.1186/s40529-025-00459-x.
Beetle rearing for food or feed is a growing area of agriculture that produces considerable wastes. This frass is a putative soil amendment anecdotally applied directly as fertilizer. To determine if beetle waste can be used as a soil amendment without pre-treatment, a series of chemical, physical, microbiological, and plant-growth assays were performed on waste from the coconut rhinoceros beetle, Oryctes rhinoceros (Coleoptera: Scarabaeidae), fed cocopeat. Beetle diet and frass NPK levels, C:N ratio, and particle size were measured. Microbiota was identified with metabarcoding, and functional profile analysis done to identify pathways associated with wood digestion or plant growth. Cultivation tests were done with Arabidopsis thaliana (Brassicales: Brassicaceae) and frass incorporation into potting soil at 0, 20, or 40%, followed by elemental concentration measurement of the soil, frass, and plant matter.
Digestion of plant polysaccharides in the gut, primarily by microbial depolymerizers, produces frass of uniform particle size and NPK 1.8-0.13-1.2 that can be used directly as a mature fertilizer without pre-composting, or even as a growth substrate. Plants with higher proportions of frass in the soil grew significantly faster and larger compared to a nutrient-rich potting soil. Frass is high in useful elements and has beneficial chitinolytic microbes.
Beetle frass can thus be used directly as a soil amendment without composting or pretreatment, with positive effects on plant growth even compared to rich soils. Valorizing frass in this way generates income for beetle farmers and recycles nutrients to soil as part of circular agriculture.
用于食品或饲料的甲虫养殖是农业中一个不断发展的领域，会产生大量废弃物。这种虫粪据传闻可直接作为肥料用于土壤改良。为了确定甲虫粪便不经预处理是否可用作土壤改良剂，我们对取食椰糠的椰心叶甲（鞘翅目：金龟子科）产生的粪便进行了一系列化学、物理、微生物和植物生长测定。测量了甲虫的食物和虫粪的氮磷钾含量、碳氮比以及颗粒大小。通过宏条形码鉴定微生物群，并进行功能谱分析以确定与木材消化或植物生长相关的途径。使用拟南芥进行培养试验，并将虫粪以0%、20%或40%的比例掺入盆栽土壤中，随后测量土壤、虫粪和植物物质中的元素浓度。
肠道中植物多糖的消化主要由微生物解聚剂完成，产生的虫粪颗粒大小均匀，氮磷钾含量为1.8 - 0.13 - 1.2，可直接用作成熟肥料，无需预先堆肥，甚至可作为生长基质。与营养丰富的盆栽土壤相比，土壤中虫粪比例较高的植物生长得更快、更大。虫粪富含有用元素且含有有益的几丁质分解微生物。
因此，甲虫虫粪无需堆肥或预处理即可直接用作土壤改良剂，即使与肥沃土壤相比，对植物生长也有积极影响。以这种方式利用虫粪可为甲虫养殖户创造收入，并作为循环农业的一部分将养分返还土壤。
