A behavioral method for separation of house fly (Diptera: Muscidae) larvae from processed pig manure

Housefly (Musca domestica) Larvae Preparations after Removing the Hydrophobic Fraction Are Effective Alternatives to Fish Meal in Aquaculture Feed for Red Seabream (Pagrus major)

Insects are an attractive alternative to fish meal (FM) as a sustainable protein source in aquaculture feed that does not negatively impact the marine ecosystem. Despite housefly (Musca domestica) larvae having adequacy of amino acid profiles, they have sometimes been reported to be inferior to FM, especially for marine carnivorous fish species. Here, we report that the removal of the hydrophobic fractions from housefly larvae enables significant replacement of FM in the diet of the red seabream (Pagrus major). In a feeding trial, housefly (HF) larvae that had the hydrophobic fraction removed as a complete substitution for 70% FM produced satisfactory growth. However, HF larvae that were supplemented with the hydrophobic fraction resulted in significant growth reduction. Growth recovery was incomplete by supplementation of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to undefatted HF larvae, being equivalent to that of fatty acid content with a control diet. Moreover, fish with a dietary intake of catechol identified from the hydrophobic fraction of the HF showed growth reduction and morphological alterations in the intestine. Our findings indicate that the hydrophobic fraction from HF larvae contains a negative factor for fish growth and eliminating the fraction from HF larvae is thought to be an important process for sustainable aquaculture.

Antidiarrheal effects of a thermostable protein fraction obtained from the larvae of Musca domestica

Our objective was to investigate whether a thermostable protein fraction (TPF) obtained from the larvae of Musca domestica, which contains cecropin family AMPs, is effective in treating senna leaf (Folium Sennae)-induced diarrhea in mice and its possible underlying mechanism. We did the experiments both in vitro and in vivo. Firstly, lipopolysaccharide (LPS) was used to induce inflammation in RAW 264.7 macrophages. The expression level of nitric oxide (NO) and tumor necrosis factor (TNF)-α was assessed using kits and immunofluorescence assay. A mice model of total diarrhea was established using a decoction of Folium Sennae. Levels of interleukin (IL)-6 and IL-1β in mice serum and of TNF-α in the supernatant of jejunal tissue homogenate were measured using commercially available ELISA kits. Hematoxylin-eosin staining was employed to evaluate pathological lesions, and immunohistochemistry was used for determining IL-1β, IL-6, and TNF-α expression levels. Results display that TPF markedly inhibited NO and TNF-α production in LPS-stimulated RAW 264.7 macrophages in vitro. Moreover, TPF significantly lowered the diarrhea index (DI) in diarrheic mice; when TPF was administered at a high dose (120 mg/kg) to mice, in comparison with mice in the model group, DI was markedly reduced. TPF could also decrease the expression levels of some pro-inflammatory factors, high dose TPF treated mice were with the reduction of (202.29 ± 18.58) pg/ml (tumor necrosis factor alpha, TNF-α), (53.69 ± 7.83) pg/ml (interleukin (IL)-1β, IL-1β), (48.44 ± 3.77) pg/ml (IL-6I, L-6) to the model separately. In comparison with berberine hydrochloride, which was used as the positive control in this study, TPF could confer better intestinal protection. To conclude, our results demonstrate that TPF has potent anti-inflammatory activities in vitro and antidiarrheal effects on mice with Folium Sennae-induced diarrhea.

The use of fly larvae for organic waste treatment

The idea of using fly larvae for processing of organic waste was proposed almost 100 years ago. Since then, numerous laboratory studies have shown that several fly species are well suited for biodegradation of organic waste, with the house fly (Musca domestica L.) and the black soldier fly (Hermetia illucens L.) being the most extensively studied insects for this purpose. House fly larvae develop well in manure of animals fed a mixed diet, while black soldier fly larvae accept a greater variety of decaying organic matter. Blow fly and flesh fly maggots are better suited for biodegradation of meat processing waste. The larvae of these insects have been successfully used to reduce mass of animal manure, fecal sludge, municipal waste, food scrapes, restaurant and market waste, as well as plant residues left after oil extraction. Higher yields of larvae are produced on nutrient-rich wastes (meat processing waste, food waste) than on manure or plant residues. Larvae may be used as animal feed or for production of secondary products (biodiesel, biologically active substances). Waste residue becomes valuable fertilizer. During biodegradation the temperature of the substrate rises, pH changes from neutral to alkaline, ammonia release increases, and moisture decreases. Microbial load of some pathogens can be substantially reduced. Both larvae and digested residue may require further treatment to eliminate pathogens. Facilities utilizing natural fly populations, as well as pilot and full-scale plants with laboratory-reared fly populations have been shown to be effective and economically feasible. The major obstacles associated with the production of fly larvae from organic waste on an industrial scale seem to be technological aspects of scaling-up the production capacity, insufficient knowledge of fly biology necessary to produce large amounts of eggs, and current legislation. Technological innovations could greatly improve performance of the biodegradation facilities and decrease production costs.

Inflammatory Regulation Effect and Action Mechanism of Anti-Inflammatory Effective Parts of Housefly (Musca domestica) Larvae on Atherosclerosis

The protein-enriched extracts of housefly larvae were segregated by gel-filtration chromatography (GFC) and then anti-inflammatory activity screening in RAW264.7 (induced by LPS) was carried out. After acquire the anti-inflammatory effective parts, its anti-atherosclerotic properties in vivo were then evaluated. Results showed that the anti-inflammatory effective parts of housefly larvae were low-molecular-weight parts. After treated with the effective parts oral gavaged for 4 weeks, the atherosclerotic lesions of the mouse were significantly decreased. The inflammatory and lipid parameters were also reduced (except HDL which was increased). Western blot analysis demonstrated that the effective parts exerted potent inhibitory effect on expression of p65 in nucleus and cytoplasm. The results of immunofluorescence microscopy analysis also showed that the expressions of p65 both in cytoplasm and nucleus were significantly reduced. The hypothesis that the anti-inflammatory effective parts of housefly larvae possessed anti-atherosclerosis activity in mouse and the possible mechanism could be associated with the inhibition of expression and nuclear transfer of NF-κB p65 could be derived.