Transcriptomic insights into developmental and nutritional shifts in Huhu (Prionoplus reticularis) grub larval stages

The Huhu grub ( Prionoplus reticularis ; Order: Coleoptera, Family: Cerambycidae, Subfamily: Prioninae - hereafter referred to as P. reticularis ) is an edible beetle larva endemic to Aotearoa New Zealand and has long been part of Māori food traditions. Despite its cultural and nutritional relevance, molecular information for this species remains scarce. In this study, we present the first de novo transcriptome assembly for P. reticularis and examine stage‑associated transcriptional differences between small and large feeding larvae using whole‑larva RNA sequencing. Distinct expression patterns were observed between the two larval size classes. Larger larvae showed increased expression of genes involved in protein synthesis, mitochondrial activity, and central metabolic processes, consistent with elevated biosynthetic demand during growth. Enrichment analyses identified over‑representation of functions related to ribosome biogenesis, oxidoreductase activity, and ATP binding, alongside conserved metabolic pathways such as glycolysis, the tricarboxylic acid cycle, and amino‑acid biosynthesis. Differences were also observed in transcripts associated with membrane transport and structural components, suggesting broader physiological shifts accompanying larval growth. Because RNA was extracted from whole larvae, these results represent organism‑level transcriptional differences and do not resolve tissue‑specific regulation. Functional and nutritional interpretations should therefore be viewed as hypothesis‑generating rather than definitive. Nevertheless, this work provides a foundational transcriptomic resource for P. reticularis and offers initial molecular insight into physiological differences within the edible larval phase. The dataset establishes a basis for future tissue‑resolved transcriptomic, proteomic, and metabolomic studies aimed at assessing nutritional properties, bioactive potential, and allergenic considerations of Huhu grub proteins.