Dawei Sun

The black soldier fly, Hermetia illucens (Linnaeus, 1758), is a globally recognized resource insect for waste bioconversion and sustainable resource provision. Understanding its larval sensory system is key to explaining feeding and environmental perception behaviors. This study used scanning and transmission electron microscopy to analyze the types, distribution, ultrastructure, and developmental consistency of sensilla on larval cephalic appendages. Five sensilla types were found on antennae, sensilla basiconica I–II, sensilla twig basiconica I–II, and sensilla campaniformia, each type comprising 2–6 sensilla. Mouthparts harbored ten types, including sensilla twig basiconica III–V, sensilla placodea, sensilla ligulate, sensilla digitiformia, sensilla trichodea, and sensilla chaetica I–III, with 2–9 sensilla per type. All sensilla showed constant numbers and positions throughout larval development. Ten sensillum types with cuticle pores were innervated by 2–6 sensory neurons, primarily suggesting chemoreceptors; these were concentrated at the tips of antennae and maxillary palps. Sensilla digitiformia on the palps possessed a non-porous cuticle and a single sensory cell, indicative of a thermo-/hygroreceptive role. Sensilla chaetica and trichodea, with non-porous cuticles and no dendrites, were mechanosensory. These results reveal the morphofunctional basis of larval sensation, supporting chemoreception studies and optimizing rearing via behavioral modulation.

With the rapid development of the livestock and poultry industry, the availability of feed resources in China has become a critical limiting factor, posing a significant challenge to the sustainable growth of animal husbandry. Black soldier fly (BSF) larvae are rich in protein, lipids, minerals, and trace elements and possess an essential amino acid profile comparable to that of fishmeal and soybean meal, which makes them a promising novel protein source for feed. This study aimed to investigate the effects of dietary BSF larvae protein supplementation on the growth performance, egg production, as well as meat and egg quality, blood biochemical parameters, and cecal microbiota diversity of Yunshang countryside chickens. The results showed that the inclusion of BSF larvae protein in the diet significantly reduced the feed-to-egg ratio and enhanced egg quality. Dietary supplementation with BSF larvae protein also effectively increased the abundance of dominant bacterial phyla and genera in the cecum, with the optimal inclusion level identified as 7.5%. Overall, the results demonstrate that BSF larvae can serve as a high-quality protein source in poultry production, thereby providing a scientific reference for the development and application of new feed resources and offering a theoretical basis for the utilization of BSF larvae as an alternative protein ingredient.

Black soldier flies (Hermetia illucens) are widely used in organic waste bioconversion, and their adaptive capacity to region-specific food waste is critical for efficient application. This study aimed to explore the molecular mechanisms underlying the adaptation of black soldier fly larvae to long-term domestication on regional food waste from Kunming and Qujing. Integrated transcriptomic and metabolomic analyses were performed to identify differences in gene expression and metabolite profiles between the two groups of larvae. The results showed significant divergence in gene expression networks, with key differences in cytochrome P450 detoxification pathways, TOR nutrient-sensing pathways, and zf-C2H2 zinc finger transcription factor families. Metabolomic analysis revealed region-specific metabolic reprogramming, including enhanced branched-chain amino acid degradation in one group and activated sphingolipid signaling pathways with accumulated indole derivatives in the other. Additionally, 13.86% of unannotated metabolites in the metabolome exhibited high connectivity in metabolic networks, suggesting potential roles as “bridge metabolites” in adaptation. These findings demonstrate that long-term domestication on regional food waste drives adaptive differentiation in black soldier fly larvae through regulatory network remodeling, metabolic reprogramming, and activation of hidden metabolic reserves. The study provides a theoretical basis for optimizing the application of black soldier flies in waste treatment and strain breeding and establishes a “substrate-gene-metabolism” multi-omics framework for understanding insect adaptive evolution.

Unlike other chicken breeds, Xichuan Black Bone (XBB) chickens are an established breed in China with excellent production performance and unique characteristics, including black meat, beaks, skin, bones, and legs, and they produce blue-shelled eggs. The Tengchong Snow (TS) chicken breed has relatively lower growth performance than commercial breeds but is considered one of the main genetic treasures of black meat in China. To improve the production and meat quality traits of the TS chickens by hybridization, the current study aimed to investigate the growth performance, carcass indices, meat quality physical properties, and muscle fiber traits of fiber traits of F1 crosses of TS with XBB chickens. Three groups of crossbreeding combinations were produced: (1) XT group (XBB × TS ), (2) TX group (TS × XBB ), and (3) TT group (TS × TS ), with the TT group used as a control. A total of 725 healthy chicks (XT group: 247, TX group: 180, TT group: 298) were reared up to 20 weeks of age to estimate the growth performance and associated meat parameters. The results showed that the XT and TX groups had higher body weight and body size compared with the TT group (p < 0.05). Similarly, breast width, breast length, width of body, and carcass weights were also greater (p < 0.05) in the XT and TX groups compared with the TT group. Meat physical properties, including color, water-holding capacity, and tenderness, were improved (p < 0.05) for the XT and TX group compared to the TT group. The XT group had the better color of the leg muscles with the unique orientation of muscle fibers. Based on the results, the XT group is more in line with the future breeding direction as they have greater body weight, larger size, and lower abdominal fat. This study is a baseline technical reference for the protection, evaluation, and utilization of germplasm resources of Tengchong Snow chicken for screening the best matching lines and combinations with local chickens.

Tengchong Snow chickens are one of the most precious, black-boned chickens in Yunnan province and usually produce black meat. However, we found a small number of white meat traits in the chicken population during feeding. In order to determine the pattern of melanin deposition and the molecular mechanism of formation in the Tengchong Snow chicken, we measured the luminance value (L value) and melanin content in the skin of black meat chickens (Bc) and white meat chickens (Wc) using a color colorimeter, ELISA kit, and enzyme marker. The results showed that the L value of skin tissues in black meat chickens was significantly lower than that of white meat chickens, and the L value of skin tissues gradually increased with an increase in age. The melanin content of skin tissues in black meat chickens was higher than that of white meat chickens, and melanin content in the skin tissues gradually decreased with an increase in age, but this difference was not significant (p > 0.05); the L value of skin tissues in black meat chickens was negatively correlated with melanin content, and the correlation coefficient was mostly above −0.6. In addition, based on the phenotypic results, we chose to perform the comparative transcriptome profiling of skin tissues at 90 days of age. We screened a total of 44 differential genes, of which 32 were upregulated and 12 were downregulated. These DEGs were mainly involved in melanogenesis, tyrosine metabolism and RNA transport. We identified TYR, DCT, and EDNRB2 as possible master effector genes for skin pigmentation in Tengchong Snow black meat chickens through DEGs analysis. Finally, we measured the mRNA of TYR, DCT, MC1R, EDNRB2, GPR143, MITF, and TYRP1 genes through a quantitative real-time polymerase chain reaction (qPCR) and found that the mRNA of all the above seven genes decreased with increasing age. In conclusion, our study initially constructed an evaluation system for the black-boned traits of Tengchong Snow chickens and found key candidate genes regulating melanin deposition, which could provide an important theoretical basis for the selection and breeding of black-boned chickens.