Digestibility of black soldier fly larvae (Hermetia illucens) fed to leopard geckos (Eublepharis macularius).

Black soldier fly (BSF) larvae have been marketed as an excellent choice for providing calcium to reptiles without the need of dusting or gut loading. However, previous studies have indicated that they have limited calcium digestibility and are deficient in fat soluble vitamins (A, D3, and E). In this feeding and digestibility trial, 24 adult male leopard geckos were fed one of three diets for 4 months: 1) whole, vitamin A gut loaded larvae; 2) needle pierced, vitamin A gut loaded larvae; or 3) whole, non-gut loaded larvae. Fecal output from the geckos was collected daily and apparent digestibility was calculated for dry matter, protein, fat, and minerals. There were no differences in digestibility coefficients among groups. Most nutrients were well digested by the leopard geckos when compared to previous studies, with the exception of calcium (digestibility co-efficient 43%), as the calcium-rich exoskeleton usually remained intact after passage through the GI tract. Biochemistry profiles revealed possible deficits occurring over time for calcium, sodium, and total protein. In regards to vitamin A digestibility, plasma and liver vitamin A concentrations were significantly higher in the supplemented groups (plasma- gut loaded groups: 33.38 ± 7.11 ng/ml, control group: 25.8 ± 6.72 ng/ml, t = 1.906, p = 0.04; liver- gut loaded groups: 28.67 ± 18.90 µg/g, control group: 14.13 ± 7.41 µg/g, t = 1.951, p = 0.03). While leopard geckos are able to digest most of the nutrients provided by BSF larvae, including those that have been gut loaded, more research needs to be performed to assess whether or not they provide adequate calcium in their non-supplemented form.

Simplified determination of the content and average degree of acetylation of chitin in crude black soldier fly larvae samples.

Insects are considered a promising alternative protein source for food and feed, but contain significant amounts of chitin, often undesirable due to indigestibility, disagreeable texture and negative effect on nutrients intake. Fractionation strategies are thus increasingly being applied to isolate and valorize chitin separately. The analysis of chitin generally requires an intensive pretreatment to remove impurities, and derivatization to generate sufficient detector response. In this work, a liquid chromatography method, without pretreatment nor derivatization, was developed for the simultaneous determination of chitin content and degree of acetylation in non-purified samples of black soldier fly (BSF) larvae. The method is found to be more suitable, compared to traditional methods, for assessing high degrees of acetylation. For the first time, the degree of acetylation of BSF chitin (81 ± 2%) is reported. Additionally, the chitin content of BSF soft tissues is estimated at approximately 20% of the total chitin content (8.5 ± 0.1%).

Aqueous ethyl acetate as a novel solvent for the degreasing of black soldier fly (Hermetia illucens L.) larvae: degreasing rate, nutritional value evaluation of the degreased meal, and thermal properties.

BACKGROUND: The aim of this study was to select appropriate low-toxicity degreasing solvents to degrease black soldier fly (BSF, Hermetia illucens L.) larvae to prepare high-quality protein. Aqueous ethyl acetate was chosen as the solvent to extract BSF protein, and traditional solvents, such as petroleum ether, n-hexane, and isopropanol, were chosen as controls. RESULTS: The meal degreased by aqueous ethyl acetate (the volume ratio of ethyl acetate to water is 90 to 10, EA + W10) shows a high degreasing rate (29.04%), crude protein content (562.3 g kg-1 ), essential amino acid index (EAAI, 95.57), and digestible indispensable amino acid score (DIAAS, 85). The digestibility of the degreased meal samples in the simulated in vitro intestine can reach 76.52%. Thermodynamic analysis and the apparent morphology of the protein fragments showed that the meal degreased by EA + W10 exhibited thermodynamic stability, which suggests that using aqueous ethyl acetate as the degreasing solvent did not affect the nutritional value of the degreased meal. CONCLUSION: The results suggest that aqueous ethyl acetate (EA + W10) can be used as a novel solvent in the degreasing of BSF larvae meal to prepare high-quality protein with high EAAI and DIAAS and good digestibility. © 2019 Society of Chemical Industry.

Total replacement of dietary fish meal with black soldier fly (Hermetia illucens) larvae does not impair physical, chemical or volatile composition of farmed Atlantic salmon (Salmo salar L.).

BACKGROUND: The aquafeed sector has been replacing conventional dietary ingredients with more economic and eco-friendly ingredients. Insects embody a promising alternative as a result of being highly nutritious and showing traits leading to a circular bioeconomy. Atlantic salmon (Salmo salar L.) at the sea-water stage were fed diets with a partial or complete substitution of fishmeal with meal of Hermetia illucens larvae reared on a media containing Ascophyllum nodosum mixed with organic wastes (60:40). The present study aimed to assess the quality of fillets by characterizing its physico-chemical traits with conventional and innovative methods, such as the proton transfer reaction-time of flight-mass spectrometer technique, allowing the analysis of samples at room temperature. Finally, steamed fillets underwent a consumer test to investigate the liking of consumers and their intention of re-consumption. RESULTS: The main findings showed that a complete dietary substitution of fishmeal with H. illucens larvae meal did not impair the physico-chemical quality of A. salmon fillets. Notably, neutral n-3 polyunsaturated fatty acids (PUFA) slightly but significantly increased in the fillets of A. salmon fed H. illucens, also as a result of the additional fish oil present in the diets containing insect. The volatile organic profile was not altered by the different diets. The consumer-liking test revealed that Italian consumers appreciated the tested salmon irrespective of the administered feed. CONCLUSION: Tailoring the insect fatty acid profile by rearing the larvae on a PUFA-rich substrate, coupled with a dietary modulation of the oily source, can successfully maintain or even increase the cardioprotective characteristics of fillets. © 2019 Society of Chemical Industry.

The Dipterose of Black Soldier Fly (Hermetia illucens) Induces Innate Immune Response through Toll-Like Receptor Pathway in Mouse Macrophage RAW264.7 Cells.

In our study, a novel bioactive polysaccharide was identified in the larvae of the black soldier fly (BSF) (Hermetia illucens) as a molecule that activates the mammalian innate immune response. We attempted to isolate this molecule, which was named dipterose-BSF, by gel-filtration and anion-exchange chromatography, followed by nitric oxide (NO) production in mouse RAW264.7 macrophage cells as a marker of immunomodulatory activity. Dipterose-BSF had an average molecular weight of 1.47 × 105 and consisted of ten monosaccharides. Furthermore, in vitro assays demonstrated that dipterose-BSF enhanced the expression of proinflammatory cytokines and interferon ß (IFNß) in RAW264.7 cells. The inhibition of Toll-like receptor 2 (TLR2) and 4 (TLR4) significantly attenuated NO production by dipterose-BSF, indicating that dipterose-BSF stimulates the induction of various cytokines in macrophages via the TLR signaling pathway. This observation was analogous with the activation of nuclear factor kappa B in RAW264.7 cells after exposure to dipterose-BSF. Our results suggest that dipterose-BSF has immunomodulatory potential through activating the host innate immune system, which allows it to be a novel immunomodulator for implementation as a functional food supplement in poultry, livestock, and farmed fish.

Black soldier fly (Hermetia illucens) larvae powder as a larval diet ingredient for mass-rearing Aedes mosquitoes.

The mass production of mosquitoes is becoming more wide-spread due to the increased application of the sterile insect technique (SIT) and other genetic control programmes. Due to the variable availability and high cost of the bovine liver powder (BLP) constituent of many current larval diets, there is an urgent demand for new ingredients in order to support sustainable and efficient mosquito production while reducing rearing cost, without affecting the quality of the insects produced. Two black soldier fly (BSF) powder-based diet formulations (50% tuna meal, 35% BSF powder, 15% brewer's yeast and 50% tuna meal + 50% BSF powder) were tested for their suitability to support the development of Aedes aegypti and Ae. albopictus mosquitoes in mass-rearing conditions. Overall, the results indicate that the use of the BSF powder did not negatively impact the development and quality of the produced insects in terms of time to pupation, adult production and male flight ability. Furthermore, depending on the species and diet formulations, there were improvements in some parameters such as female body size, egg production, egg hatch rate and male longevity. BSF powder is a valuable ingredient that can effectively replace costly BLP for the mass production of high quality Ae. aegypti and Ae. albopictus mosquitoes. Both diet formulations can be used for Ae. aegypti showing high plasticity to nutrition sources. However, for Ae. albopictus we recommend the combination including brewer's yeast.

TITLE: La poudre de larves de mouche-soldat noire (Hermetia illucens) comme ingrédient alimentaire pour l'élevage de masse des moustiques Aedes. ABSTRACT: L'élevage de masse de moustiques est de plus en plus répandu en raison de l'application de la technique de l'insecte stérile et d'autres techniques de lutte génétique. En raison de la disponibilité variable et du coût élevé de la poudre de foie de bovin, ingrédient de nombreux régimes larvaires, il devient urgent de trouver de nouveaux ingrédients afin de soutenir une production durable et efficace des moustiques, en réduisant les coûts d'élevage sans toutefois affecter la qualité des insectes produits. Deux formulations de régime à base de poudre de mouche-soldat noire (50 % farine de thon + 35 % poudre de mouche-soldat noire + 15 % levure de bière et 50 % farine de thon + 50 % poudre de mouche-soldat noire) ont été évaluées pour déterminer leur capacité à soutenir le développement larvaire d'Aedes aegypti et Ae. albopictus dans des conditions d'élevage de masse. Dans l'ensemble, les résultats indiquent que l'utilisation de la poudre de mouche-soldat noire n'a pas d'impact négatif sur le développement larvaire et la qualité des insectes produits en termes de temps de développement, de production d'adultes et de capacité de vol des mâles. En outre, en fonction de l'espèce et de la formulation du régime, certains paramètres tels que la taille des femelles, la production d'œufs, le taux d'éclosion des œufs et la longévité des mâles ont été améliorés. La poudre de mouche-soldat noire est un ingrédient de valeur qui peut remplacer efficacement la coûteuse poudre de foie de bovin pour la production en masse de moustiques Ae aegypti et Ae. albopictus de grande qualité. Les deux formules de régime peuvent être utilisées pour Ae. aegypti qui montre une grande plasticité à la source de nutrition. Cependant, pour Ae. albopictus, nous recommandons la formulation comprenant la levure de bière.

The nutritive value of black soldier fly larvae reared on common organic waste streams in Kenya.

In Africa, livestock production currently accounts for about 30% of the gross value of agricultural production. However, production is struggling to keep up with the demands of expanding human populations, the rise in urbanization and the associated shifts in diet habits. High costs of feed prevent the livestock sector from thriving and to meet the rising demand. Insects have been identified as potential alternatives to the conventionally used protein sources in livestock feed due to their rich nutrients content and the fact that they can be reared on organic side streams. Substrates derived from organic by-products are suitable for industrial large-scale production of insect meal. Thus, a holistic comparison of the nutritive value of Black Soldier Fly larvae (BSFL) reared on three different organic substrates, i.e. chicken manure (CM), brewers' spent grain (SG) and kitchen waste (KW), was conducted. BSFL samples reared on every substrate were collected for chemical analysis after the feeding process. Five-hundred (500) neonatal BSFL were placed in 23 × 15 cm metallic trays on the respective substrates for a period of 3-4 weeks at 28 ± 2 °C and 65 ± 5% relative humidity. The larvae were harvested when the prepupal stage was reached using a 5 mm mesh size sieve. A sample of 200 grams prepupae was taken from each replicate and pooled for every substrate and then frozen at -20 °C for chemical analysis. Samples of BSFL and substrates were analyzed for dry matter (DM), crude protein (CP), ether extracts (EE), ash, acid detergent fibre (ADF), neutral detergent fibre (NDF), amino acids (AA), fatty acids (FA), vitamins, flavonoids, minerals and aflatoxins. The data were then subjected to analysis of variance (ANOVA) using general linear model procedure. BSFL differed in terms of nutrient composition depending on the organic substrates they were reared on. CP, EE, minerals, amino acids, ADF and NDF but not vitamins were affected by the different rearing substrates. BSFL fed on different substrates exhibited different accumulation patterns of minerals, with CM resulting in the largest turnover of minerals. Low concentrations of heavy metals (cadmium and lead) were detected in the BSFL, but no traces of aflatoxins were found. In conclusion, it is possible to take advantage of the readily available organic waste streams in Kenya to produce nutrient-rich BSFL-derived feed.

Characterization of IgE-binding proteins in the salivary glands of Simulium nigrogilvum (Diptera: Simuliidae).

Simulium dermatitis is an IgE-mediated skin reaction in animals and humans caused by the bites of black flies. Although Simulium nigrogilvum has been incriminated as the main human-biting black fly species in Thailand, information on its salivary allergens is lacking. Salivary gland extract of S. nigrogilvum females was subjected to sodium dodecylsulfate-polyacrylamide gel electrophoresis, and the separated components were applied onto nitrocellulose membranes for immunoblotting, which was performed by probing the protein blots with sera from 17 individuals who were allergic to the bites of S. nigrogilvum. IgE-reactive protein bands were characterized further by liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Nine protein bands (79, 42, 32, 25, 24, 22, 15, 13, and 11 kDa) were recognized in the serum of the subjects. Four of the nine protein bands (32, 24, 15, and 11 kDa) showed IgE reactivity in all (100%) of the tested sera, and they were identified as salivary secreted antigen 5-related protein, salivary serine protease, erythema protein, and hypothetical secreted protein, respectively. Three other proteins, salivary serine protease (25 kDa), salivary D7 secreted protein (22 kDa), and hypothetical protein (13 kDa), reacted with > 50% of the sera. The relevance of the identified protein bands as allergens needs to be confirmed by using pure recombinant proteins, either in the in vivo skin prick test or in vitro detection of the specific IgE in the serum samples of allergic subjects. This will be useful for the rational design of component-resolved diagnosis and allergen immunotherapy for the allergy mediated by the bites of black flies.

Do dietary soy alternatives lead to pork quality improvements or drawbacks? A look into micro-alga and insect protein in swine diets.

Pork quality characteristics related to the dietary substitution of soybean meal by the micro-alga Spirulina (Arthrospira platensis) or black soldier fly (Hermetia illucens) partly-defatted larval meal were observed. Through a duplicated study totalling 48 individually-fed barrows (Pietrain × (Large White × Landrace)) allocated into two experimental groups and a control, the effect of dietary protein source on physico-chemical and sensory pork quality was monitored under current industrial packaging conditions (highly­oxygenated modified atmosphere packaging). The results show that physico-chemical characteristics are not degraded by including alternative protein sources in pig diets. Hermetia illucens increased lauric acid levels in backfat indicating that this fatty acid may be suitable as a biomarker for Hermetia illucens-fed pork. This goes to show that protein alternatives do not compromise pork quality.

Influence of the killing method of the black soldier fly on its lipid composition.

Black soldier fly (BSF, Hermetia illucens) represents a valuable source of biomolecules and it also constitutes an economic way to valorise residual biomasses. BSF prepupae contain high amounts of lipids (37% DM basis). The present investigation aimed at studying the composition of BSF lipids and the effect of killing/storage on their quality. The main fatty acid was lauric acid, sterols were represented primarily by beta-sitosterol and campesterol. Global fatty acid and sterol profiles, determined by GC-MS, were only slightly affected by the killing procedure, while lipid classes distribution, determined by 1H NMR, strongly changed. Prepupae killed by freezing showed a drastic reduction of acylglycerols during storage and a relevant release of free fatty acids, likely due to activation of lipases. On the contrary, prepupae killed by blanching have a stable lipid fraction constituted mainly by triacylglycerols. Therefore, killing procedure strongly influences BSF oil composition and the potential applications.

Killing method affects the browning and the quality of the protein fraction of Black Soldier Fly (Hermetia illucens) prepupae: a metabolomics and proteomic insight.

Insects are being explored as novel protein sources in order to overcome the future food demands connected to world growing population. Insects for food/feed uses are currently slowly killed through freezing by most insect rearing companies, and typically, enzymatic browning takes place in the insect proteins fractions. However, very little is known about the influence of these enzymatic reactions on the protein physical, chemical, nutritional and technological properties. In this work a metabolomics and proteomic study was conducted on Black Soldier Fly (Hermetia illucens) prepupae, killed by two different methods: freezing (commonly used), and blanching (with the aim to inhibit the enzymatic activities). Proton nuclear magnetic resonance (1H NMR) metabolomics demonstrated that slow killing method by freezing, compared with blanching, elicits the activation of several enzymatic pathways, among them melanisation with tyrosine consumption, energetic metabolism and lipolysis. These metabolic changes have an impact also on protein nutritional quality, with a loss of cysteine and lysine, likely involved in the process of melanisation and enzymatic browning. A strong effect was also observed on protein extractability: proteins from prepupae killed by blanching were found to be more extractable in milder conditions by chemical methods, and more prone to enzymatic digestion (97% of proteins released in solution upon proteolysis) than proteins from prepupae killed by freezing. All these data indicate that killing by blanching inhibits the browning reaction and other enzymatic changes occurring during slow killing by freezing, increasing the extractability of proteins in aqueous solutions, avoiding essential amino acid loss, and improving enzymatic digestibility.

Bio-Based Electrospun Nanofiber of Polyhydroxyalkanoate Modified with Black Soldier Fly's Pupa Shell with Antibacterial and Cytocompatibility Properties.

We report on the antibacterial and cytocompatibility properties of a bio-based electrospun polyhydroxyalkanoate (PHA) nanofiber modified with Black Soldier Fly (BSF) pupa shell. A 5-50 µm chitosan powder (CSP) was made by grinding BSF pupa shell in water, acid, alkali. CSP was combined with PHA in an electrospinning machine using a biaxial feed method and manufactured into a 50-500 nm antibacterial nanofiber. We studied the morphology, mechanical properties, water absorption, and antibacterial properties of the electrospun PHA/CSP nanofiber. To improve the fiber's compatibility and functionality, acrylic acid (AA) was grafted onto PHA. The resulting tensile properties and morphological characterizations indicated enhanced adhesion between CSP and PHA- g-AA nanofiber, as well as an improvement in its water resistance and tensile strength, compared with the PHA/CSP nanofiber. To study the cytocompatibility of the material, human foreskin fibroblasts were seeded onto the nanofiber specimens with 3.0 and 6.0 wt % CSP. Increasing the CSP content in PHA/CSP and PHA- g-AA/CSP nanofibers enhanced cell proliferation; additionally, the nanofibers with CSP showed strong inhibition of bacteria. The enhanced antibacterial and biodegradable properties of PHA- g-AA/CSP and PHA/CSP nanofibers demonstrate their potential for biomedical material applications.

Effect of rearing substrate on growth performance, waste reduction efficiency and chemical composition of black soldier fly (Hermetia illucens) larvae.

BACKGROUND: Wastes can be used as rearing substrate by black soldier fly (BSF) larvae, the latter being exploitable as a protein source in animal feed. This research aimed to assess the influence of four rearing substrates (Trial 1 (organic wastes): a mixture of vegetable and fruit (VEGFRU) vs. a mixture of fruits only (FRU); Trial 2 (agro-industrial by-products): brewery (BRE) vs. winery (WIN) by-products) on BSF larvae development, waste reduction efficiency and nutritional composition. RESULTS: If respectively compared to FRU and WIN, VEGFRU and BRE larvae needed less time to reach the prepupal stage (22.0, 22.2, 20.2 and 8.0 days of trial, respectively) and had higher protein content (229.7, 257.3, 312.9 and 395.7 g kg-1 dry matter). The waste reduction index ranged from 2.4 (WIN) to 5.3 g d-1 (BRE). BRE larvae showed the lowest saturated and the highest polyunsaturated fatty acid proportions (612.4 and 260.1 g kg-1 total fatty acids, respectively). CONCLUSION: Vegetable and fruit wastes and winery by-products can be used as rearing substrates for BSF larval mass production. Brewery by-products led to very promising larval performance and nutritional composition. However, given BRE limited availability, low BRE dietary inclusion levels could be used with the purpose of increasing larval performance. © 2018 Society of Chemical Industry.

Moisture adsorption properties and shelf-life estimation of dried and pulverised edible house cricket Acheta domesticus (L.) and black soldier fly larvae Hermetia illucens (L.).

Edible insects are part of the diets of a significant proportion of rural populations in the tropics especially Africa and Asia, and their use as source of key nutrients for better nutrition is re-emerging. Indigenously, elemental methods are used to process the insects before they are consumed or sold in retail outlets. In recent years, better knowledge of processing, packaging and storage has become necessary because of commercialisation needs. A common processing approach involves drying after a brief heat-treatment step, and then milling into a powdered product which is sold to manufacturers or consumers as ingredient for processing final products. The hydration properties of dried powders of edible house cricket and black soldier fly larvae (BSFL) were studied with the aim of predicting shelf-life stability under typical packaging and storage temperatures experienced in the tropics. Moisture adsorption isotherms were determined gravimetrically at 25, 30 and 35 °C, over 0.11-0.97 water activity (aW) range, and the data fitted to various models. Sorption isotherms were of type II according to Brunauer classification indicating monolayer-multilayer sorption behaviour. Cricket powder exhibited higher hydration capacity, and aW of this product was less sensitive to temperature variation as compared to BSFL powder. In the two products, water exhibited transitions from bound- to free- state at ~5 g/100 g moisture content. Based on Heiss-Eichner model, a shelf-life of 7 months at 25 °C can be achieved if the cricket and BSFL powders are dried to ca. 5 g/100 g moisture content and packaged in 80 µm thick polyethylene films. At 35 °C the shelf-life of the cricket product is shortened three- to four-fold whereas the BSFL powder is unable to store.

Impact of substrate contamination with mycotoxins, heavy metals and pesticides on the growth performance and composition of black soldier fly larvae (Hermetia illucens) for use in the feed and food value chain.

Edible insects have emerged as an alternative and sustainable source of high-quality, animal-derived protein and fat for livestock production or direct human nutrition. During the production of insects, substrate quality is a key parameter to assure optimal insect biomass gain as well as the safety of feed and food derived from commercially reared insects. Therefore, the influence of a realistic substrate contamination scenario on growth performance and accumulation behaviour of black soldier fly larvae (BSFL; Hermetia illucens L.) was investigated. Newly hatched larvae were fed on a corn-based substrate spiked with heavy metals (As, Cd, Cr, Hg, Ni, Pb), mycotoxins (aflatoxins B1/B2/G2, deoxynivalenol, ochratoxin A, zearalenone) and pesticides (chlorpyrifos, chlorpyrifos-methyl, pirimiphos-methyl) under defined breeding conditions (10 days, 28°C, 67% relative humidity). The extent of contaminants' bioaccumulation in the larval tissue as well as the effect on growing determinants were examined. The applied heavy metal substrate contamination was shown to impair larval growing indicated by significantly lower post-trial larval mass and feed conversion ratio (FCR). Cd and Pb accumulation factors of 9 and 2, respectively, were determined, while the concentrations of other heavy metals in the larvae remained below the initial substrate concentration. In contrast, mycotoxins and pesticides have neither been accumulated in the larval tissue nor significantly affected the growing determinants in comparison with the control. The use of BSFL as livestock feed requires contaminant monitoring - especially for Cd and Pb - in the substrates as well as in feedstuff containing BSFL to ensure feed and food safety along the value chain.

Black soldier fly as dietary protein source for broiler quails: apparent digestibility, excreta microbial load, feed choice, performance, carcass and meat traits.

In order to expand with validated scientific data the limited knowledge regarding the potential application of insects as innovative feed ingredients for poultry, the present study tested a partial substitution of soya bean meal and soya bean oil with defatted black soldier fly (Hermetia illucens) larvae meal (H) in the diet for growing broiler quails (Coturnix coturnix japonica) on growth performance, mortality, nutrients apparent digestibility, microbiological composition of excreta, feed choice, carcass and meat traits. With this purpose, a total of 450 10-day-old birds were allocated to 15 cages (30 birds/cage) and received three dietary treatments: a Control diet (C) and two diets (H1 and H2) corresponding to 10% and 15% H inclusion levels, respectively (H substituted 28.4% soya bean oil and 16.1% soya bean meal for H1, and 100% soya bean oil and 24.8% soya bean meal for H2, respectively). At 28 days of age, quails were slaughtered, carcasses were weighed, breast muscles were then excised from 50 quails/treatment, weighed, and ultimate pH (pHu) and L*, a*, b* colour values were measured. Breast muscles were then cooked to assess cooking loss and meat toughness. For the digestibility trial, a total of 15 28-day-old quails were assigned to the three feeding groups. The excreta samples were subjected to chemical and microbiological analysis. The same 15 quails were then simultaneously provided with C and H2 diets for a 10-day feed choice trial. Productive performance, mortality and carcass traits were in line with commercial standards and similar in all experimental groups. With the exception of ether extract digestibility, which was lower in H1 group compared with C and H2 (P=0.0001), apparent digestibility of dry matter, CP, starch and energy did not differ among treatments. Microbial composition of excreta was also comparable among the three groups. Feed choice trial showed that quails did not express a preference toward C or H2 diets. Breast meat weight and yield did not differ among C, H1 and H2 quails. Differently, the inclusion of H meal reduced meat pHu compared with C. In conclusion, this study demonstrated that H. illucens larvae meal can partially replace conventional soya bean meal and soya bean oil in the diet for growing broiler quails, thus confirming to be a promising insect protein source for the feed industry. Further research to assess the impact of H meal on intestinal morphology as well as on meat quality and sensory profile would be of utmost importance.

Identification of communal oviposition pheromones from the black fly Simulium vittatum.

The suite of pheromones that promote communal oviposition by Simulium vittatum, a North American black fly species, was identified and characterized using gas chromatography-mass spectrometry, electrophysiological, and behavioral bioassays. Behavioral assays demonstrated that communal oviposition was induced by egg-derived compounds that were active at short range and whose effect was enhanced through direct contact. Three compounds (cis-9-tetradecen-1-ol, 1-pentadecene, and 1-tridecene) were identified in a non-polar solvent extract of freshly deposited S. vittatum eggs that were capable of inducing the oviposition response. Electroantennography demonstrated that two of these three compounds (1-pentadecene and 1-tridecene) actively stimulated antennal neurons. Identification of the oviposition pheromones of this family may be helpful in developing control measures for nuisance black flies and for medically-important species such as Simulium damnosum sensu lato.

Purification and characterization of a novel defensin from the salivary glands of the black fly, Simulium bannaense.

BACKGROUND: Black flies (Diptera: Simuliidae) are haematophagous insects that can cause allergic reactions and act as vectors of pathogens. Although their saliva has been thought to contain a diverse array of physiologically active molecules, little information is available on antimicrobial factors in black fly salivary glands, especially no defensins have been reported so far. METHODS: A novel cationic defensin designated SibaDef was purified using reverse phase high-performance liquid chromatography (RP-HPLC) from the salivary glands of the black fly Simulium bannaense. The amino acid sequence of SibaDef was determined by a combination method of automated Edman degradation and cDNA sequencing. The morphologic changes of Gram-positive bacteria Staphylococcus aureus or Bacillus subtilis treated with SibaDef were assessed by scanning electron microscopy (SEM). Quantitative PCR (qPCR) was performed to analyze the expression of SibaDef mRNA in whole bodies of insects after oral infection with the bacteria S. aureus or B. subtilis. RESULTS: Surprisingly, the phylogenetic analysis of defensin-related amino acid sequences demonstrated that SibaDef is most closely related to defensins from the human body louse Pediculus humanus corporis (Anoplura: Pediculidae), rather than to other dipteran defensins. SibaDef showed potent antimicrobial activities against Gram-positive bacteria with minimal inhibitory concentrations (MICs) ranging from 0.83 µM to 2.29 µM. SEM analysis indicated that SibaDef killed microorganisms through the disruption of cell membrane integrity. The transcript levels of SibaDef in the bacteria-immunized flies increased with the time course, reaching maximum at 36 h and then slowly decreased from that time point. CONCLUSIONS: Our results indicate that SibaDef is involved in the innate humoral response of the black fly S. bannaense, and it might play a significant role in the defence against microorganisms in both sugar and blood meals.

Novel aquatic silk genes Simulium (Psilozia) vittatum (Zett) Diptera: Simuliidae.

The silks of arthropods have an elementary role in the natural history of the organisms that spin them, yet they are coded by rapidly evolving genes leading some authors to speculate that silk proteins are non-homologous proteins co-opted multiple times independently for similar functions. However, some general structural patterns are emerging. In this work we identified three major silk gland proteins using a combined biochemical, proteomic, next-generation sequencing and bioinformatic approach. Biochemical characterization determined that they were phosphorylated with multiple isoforms and potentially differential phosphorylation. Structural characterization showed that their structure was more similar to silk proteins from distantly related aquatic Trichopteran species than more closely related terrestrial or aquatic Diptera. Overall, our approach is easily transferable to any non-model species and if used across a larger number of aquatic species, we will be able to better understand the processes involved in linking the secondary structure of silk proteins with their function between in an organisms and its habitat.

Distribuição e abundância de larvas de Simulium spp. em córregos do estado de São Paulo nos diferentes níveis de qualidade da água / Distribution and abundance of Simulium spp. in streams of the state of São Paulo (Brazil) with different water quality

O objetivo deste trabalho foi determinar a distribuição e a abundância de espécies do gênero Simulium em 5 córregos do litoral norte paulista, com diferentes níveis de poluição.Larvas de simulídeos e amostras de água de cada córrego foram coletadas quinzenalmente no verão e no inverno de 2001. Para a amostragem das larvas foram colocados substratos artificiais em triplicata. A cada intervalo de 15 dias as larvas foram retiradas com auxílio de pinças entomológicas, acondicionadas em frascos de vidro com álcool 70% e transportadas ao laboratório para triagem, contagem e identificação. Nos locais da coleta foram obtidos valores de temperatura, oxigênio, condutividade, pH da água e vazão do córrego e em laboratório as amostras de água foram analisadas, obtendo-se valor es de nitrogênio total e dissolvido, N-amoniacal, N-nitrito, N-nitrato, ortofosfato, fósforo total e dissolvido. Pode-se observar que a qualidade da água foi um fator determinante tanto para a distribuição como para a abundância das espécies. S. pertinax ocorreu em ambientesmais limpos, S. inaequale nos mais poluídos e S. incrustatum nos intermediários.A espécie predominante foi S. pertinax com 57,5% de presença total nos criadouros, S.inaequale com 42,1% e S. incrustatum com pouca representatividade, 0,4% de presençanas amostras. A menor abundância de larvas foi registrada nos ambientes poluídos...

The aim of this work was to determine the distribution and abundance the species of Simulium:in 5 streams of the north coastal region of the state of São Paulo. Simulium larval andwater samples were collected every 2 weeks in summer and winter, 2001. The larval werecollected on artificial substrates (triplicate) preserved in alcohol (70%) and after analyzedquantitative and qualitative. From the streams the values of temperature, dissolved oxygen,conductivity, pH and stream discharge were measured. The contents of total nitrogenand dissolved nitrogen, ammoniacal nitrogen, nitrate, nitrite, orthophosphate, dissolvedphosphorus and total phosphorus were determined in the laboratory. Water quality hasgreat influence in the distribution and abundance of the species. S. pertinax was moreabundant in streams without or with low levels of pollution, S. inaequale in streams morepolluted and S. incrustatum in intermediary levels of pollution. S. pertinax was the speciesmore abundant with 57.5% of presence in the samples, the second more abundant wasS. inaequale with 42.1% of presence and S. incrustatum was rare with 0.4% of presence.The larval abundance was lower in the polluted environment...