Reproductive output and other adult life-history traits of black soldier flies grown on different organic waste and by-products.

The interest in mass-rearing black soldier fly (Hermetia illucens) larvae for food and feed is rapidly increasing. This is partly sparked by the ability of the larvae to efficiently valorise a wide range of organic waste and by-products. Primarily, research has focused on the larval stage, hence underprioritizing aspects of the adult biology, and knowledge on reproduction-related traits such as egg production is needed. We investigated the impact of different organic waste and by-products as larval diets on various life-history traits of adult black soldier flies in a large-scale experimental setup. We reared larvae on four different diets: spent Brewer's grain, ground carrots, Gainesville diet, and ground oranges. Traits assessed were development time to pupa and adult life-stages, adult body mass, female lifespan, egg production, and egg hatch. Larval diet significantly impacted development time to pupa and adult, lifespan, body size, and egg production. In general, flies reared on Brewer's grain developed up to 4.7 d faster, lived up to 2.3 d longer, and produced up to 57% more eggs compared to flies reared on oranges on which they performed worst for these traits. There was no effect of diet type on egg hatch, suggesting that low-nutritious diets, i.e. carrots and oranges, do not reduce the quality but merely the quantity of eggs. Our results demonstrate the importance of larval diet on reproductive output and other adult traits, all important for an efficient valorisation of organic waste and by-products, which is important for a sustainable insect-based food and feed production.

Description of the male of Simulium triglobus Takaoka & Kuvangkadilok (Diptera: Simuliidae) from Thailand.

Simulium triglobus Takaoka & Kuvangkadilok from Thailand, in the Simulium (Simulium) multistriatum species-group, is unique among species in the family Simuliidae in having the female terminalia with three spermathecae (rather than one spermatheca). This species was described from Nan province, northern Thailand based on larvae, pupae and females but its male has remained unknown. In this study, the male of S. triglobus is described for the first time based on adult males reared from pupae collected from the type locality. The most distinctive characteristic of the male of S. triglobus is the shape of the ventral plate, which is hexagonal when viewed ventrally. No other members of S. multistriatum species group known thus far have such a unique ventral plate. In addition, the number of upper-eye (large) facets and color patterns of the legs can be used to differentiate this species in the male from other members of the S. multistriatum species-group. Mitochondrial cytochrome c oxidase I sequences enabled association of adult male specimens of S. triglobus with previously known life stages. Phylogenetic analysis based on these sequences revealed that specimens of S. triglobus formed a strongly supported monophyletic clade, being genetically distinct from other members of S. multistriatum species-group in Thailand.

Destabilization of the Bacterial Interactome Identifies Nutrient Restriction-Induced Dysbiosis in Insect Guts.

Stress-associated dysbiosis of microbiome can have several configurations that, under an energy landscape conceptual framework, can change from one configuration to another due to different alternating selective forces. It has been proposed-according to the Anna Karenina Principle-that in stressed individuals the microbiome are more dispersed (i.e., with a higher within-beta diversity), evidencing the grade of dispersion as indicator of microbiome dysbiosis. We hypothesize that although dysbiosis leads to different microbial communities in terms of beta diversity, these are not necessarily differently dispersed (within-beta diversity), but they form disrupted networks that make them less resilient to stress. To test our hypothesis, we select nutrient restriction (NR) stress that impairs host fitness but does not introduce overt microbiome selectors, such as toxic compounds and pathogens. We fed the polyphagous black soldier fly, Hermetia illucens, with two NR diets and a control full-nutrient (FN) diet. NR diets were dysbiotic because they strongly affected insect growth and development, inducing significant microscale changes in physiochemical conditions of the gut compartments. NR diets established new configurations of the gut microbiome compared to FN-fed guts but with similar dispersion. However, these new configurations driven by the deterministic changes induced by NR diets were reflected in rarefied, less structured, and less connected bacterial interactomes. These results suggested that while the dispersion cannot be considered a consistent indicator of the unhealthy state of dysbiotic microbiomes, the capacity of the community members to maintain network connections and stability can be an indicator of the microbial dysbiotic conditions and their incapacity to sustain the holobiont resilience and host homeostasis. IMPORTANCE Changes in diet play a role in reshaping the gut microbiome in animals, inducing dysbiotic configurations of the associated microbiome. Although studies have reported on the effects of specific nutrient contents on the diet, studies regarding the conditions altering the microbiome configurations and networking in response to diet changes are limited. Our results showed that nutrient poor diets determine dysbiotic states of the host with reduction of insect weight and size, and increase of the times for developmental stage. Moreover, the poor nutrient diets lead to changes in the compositional diversity and network interaction properties of the gut microbial communities. Our study adds a new component to the understanding of the ecological processes associated with dysbiosis, by disentangling consequences of diets on microbiome dysbiosis that is manifested with the disruption of microbiome networking properties rather than changes in microbiome dispersion and beta diversity.

Comparisons of Respiratory Pupal Gill Development in Black Flies (Diptera: Simuliidae) Shed Light on the Origin of Dipteran Prothoracic Dorsal Appendages.

During the transformation of immature aquatic dipteran insects to terrestrial adults, the prothoracic pupal respiratory organ enables pupae to cope with flood-drought alternating environments. Despite its obvious importance, the biology of the organ, including its development, is poorly understood. In this study, the developing gills of several Simulium Latreille (Diptera: Simuliidae) spp. were observed using serial histological sections and compared with data on those of other dipteran families published previously. The formation of some enigmatic features that made the Simulium gill unique is detailed. Through comparisons between taxa, we describe a common developmental pattern in which the prothoracic dorsal disc cells not only morph into the protruding respiratory organ, which is partially or entirely covered with a cuticle layer of plastron, but also invaginate to form a multipart internal chamber that in part gives rise to the anterior spiracle of adult flies. The gill disc resembles wing and leg discs and undergoes cell proliferation, axial outgrowth, and cuticle sheath formation. The overall appendage-like characteristics of the dipteran pupal respiratory organ suggest an ancestral form that gave rise to its current forms, which added more dimensions to the ways that arthropods evolved through appendage adaptation. Our observations provide important background from which further studies into the evolution of the respiratory organ across Diptera can be carried out.

Pedrowygomyia (Diptera: Simuliidae): Discovery of a New Species After 30 yr.

Pedrowygomyia is a Neotropical genus of Simuliidae composed of four species; all were described in 1989 from high-elevation (above 3,000 m) areas in the Andean region. In this article, a new species for this genus, Pedrowygomyia hanaq n. sp., is described based on all stages of development. The new species was collected in the south-central Andes of Peru at an altitude above 4,000 m, and its known distribution is currently restricted to the type-locality. Based on the pupal stage, the new species appears to be more closely related to Pedrowygomyia punapi (Wygodzinsky & Coscarón) (Diptera: Simuliidae), a species known from Argentina, Bolivia, and Chile.

Biochar and gypsum amendment of agro-industrial waste for enhanced black soldier fly larval biomass and quality frass fertilizer.

Black soldier fly (BSF) (Hermetia illucens L.) is one of the most efficient bio-waste recyclers. Although, waste substrate amendments with biochar or gypsum during composting process are known to enhance nutrient retention, their impact on agro-industrial waste have not been documented. Hence, this study focuses on a comparative effect of agro-industrial waste amended with biochar and gypsum on BSF larval performance, waste degradation, and nitrogen (N) and potassium retention in frass fertilizer. Brewery spent grain was amended with biochar or gypsum at 0, 5, 10, 15 and 20% to determine the most effective rates of inclusion. Amending feedstock with 20% biochar significantly increased wet (89%) and dried (86%) larval yields than the control (unamended feedstock). However, amendment with 15% gypsum caused decrease in wet (34%) and dried (30%) larval yields but conserved the highest amount of N in frass. Furthermore, the inclusion of 20% biochar recorded the highest frass fertilizer yield and gave a 21% increase in N retention in frass fertilizer, while biomass conversion rate was increased by 195% compared to the control. Feedstock amendment with 5% biochar had the highest waste degradation efficiency. Potassium content in frass fertilizer was also significantly enhanced with biochar amendment. At maturity, frass compost with more than 10% inclusion rate of biochar had the highest cabbage seed germination indices (>100%). The findings of this study revealed that initial composting of biochar amended feedstocks using BSF larvae can significantly shorten compost maturity time to 5 weeks with enhanced nutrient recycling compared to the conventional composting methods.

Hermetia illucens (Diptera: Stratiomydae) larvae and prepupae: Biomass production, fatty acid profile and expression of key genes involved in lipid metabolism.

The Black Soldier Fly (BSF) Hermetia illucens provides a promising strategy in the waste valorisation process and a sustainable alternative source of valuable nutrients, including lipids for food and feed. In the present study, the differences in growth performances and nutritional values of BSF V instar larvae and prepupae reared on vegetable waste were analyzed and compared focusing on fat content. V instar larvae showed higher capacity to bioconvert the substrate into biomass than prepupae. The nutritional composition and the fatty acid profiles were dependent on the developmental stage. The expression levels of acetyl-CoA carboxylase (acc), fatty acid synthase (fas), lipase (lip) and acyl-CoA dehydrogenase (acd) genes involved in the lipid metabolism pathway and herein characterized for the first time, were evaluated in order to understand the molecular basis underlying the observed differences in fatty acid profiles. Our results suggest that the different fatty acid profiles of BSF V instar larvae and prepupae may be related to the modulation of the lipid metabolism-related genes expression during larval development. Our study highlights substantial differences between H. illucens V instar larvae and prepupae giving important features regarding the opportunity to modulate the preferable fatty acid profile to meet the industrial requirements.

Revision of Simulium rufibasis (Diptera: Simuliidae) in Japan and Korea: Chromosomes, DNA, and Morphology.

The widespread nominal black fly Simulium (Simulium) rufibasis Brunetti was reexamined morphologically, chromosomally, and molecularly to determine the status of populations in Japan and Korea with respect to S. rufibasis from the type locality in India and to all other known species in the S. (S.) tuberosum species-group. Morphological comparisons established that the species previously known as S. rufibasis in Japan and Korea is distinct from all other species. Consequently, it was described and illustrated as a new species, Simulium (S.) yamatoense. Simulium yokotense Shiraki, formerly a synonym of S. rufibasis, was morphologically reevaluated and considered a species unplaced to species-group in the subgenus Simulium. Chromosomal analyses of S. yamatoense sp. nov. demonstrated that it is unique among all cytologically known species of the S. tuberosum group and is the sister species of the Taiwanese species tentatively known as S. (S.) arisanum Shiraki. Populations of S. yamatoense sp. nov. included two cytoforms, based on the sex chromosomes. Cytoform A, including topotypical representatives, was found in Kyushu, Japan, whereas cytoform B was found in Korea and Honshu, Japan. Molecular analysis based on the COI mitochondrial gene generally corroborated morphological and chromosomal data that S. yamatoense sp. nov. is a distinct species and, like the chromosomal data, indicate that it is most closely related to S. arisanum, with interspecific genetic distance of 2.92-4.63%.

Modelling exposure heterogeneity and density dependence in onchocerciasis using a novel individual-based transmission model, EPIONCHO-IBM: Implications for elimination and data needs.

BACKGROUND: Density dependence in helminth establishment and heterogeneity in exposure to infection are known to drive resilience to interventions based on mass drug administration (MDA). However, the interaction between these processes is poorly understood. We developed a novel individual-based model for onchocerciasis transmission, EPIONCHO-IBM, which accounts for both processes. We fit the model to pre-intervention epidemiological data and explore parasite dynamics during MDA with ivermectin. METHODOLOGY/PRINCIPAL FINDINGS: Density dependence and heterogeneity in exposure to blackfly (vector) bites were estimated by fitting the model to matched pre-intervention microfilarial prevalence, microfilarial intensity and vector biting rate data from savannah areas of Cameroon and Côte d'Ivoire/Burkina Faso using Latin hypercube sampling. Transmission dynamics during 25 years of annual and biannual ivermectin MDA were investigated. Density dependence in parasite establishment within humans was estimated for different levels of (fixed) exposure heterogeneity to understand how parametric uncertainty may influence treatment dynamics. Stronger overdispersion in exposure to blackfly bites results in the estimation of stronger density-dependent parasite establishment within humans, consequently increasing resilience to MDA. For all levels of exposure heterogeneity tested, the model predicts a departure from the functional forms for density dependence assumed in the deterministic version of the model. CONCLUSIONS/SIGNIFICANCE: This is the first, stochastic model of onchocerciasis, that accounts for and estimates density-dependent parasite establishment in humans alongside exposure heterogeneity. Capturing the interaction between these processes is fundamental to our understanding of resilience to MDA interventions. Given that uncertainty in these processes results in very different treatment dynamics, collecting data on exposure heterogeneity would be essential for improving model predictions during MDA. We discuss possible ways in which such data may be collected as well as the importance of better understanding the effects of immunological responses on establishing parasites prior to and during ivermectin treatment.

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.

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.

Threshold temperatures and thermal requirements of black soldier fly Hermetia illucens: Implications for mass production.

Efforts to recycle organic wastes using black soldier fly (BSF) Hermetia illucens into high-nutrient biomass that constitutes a sustainable fat (biodiesel) and high-quality protein ingredient in animal feeds have recently gained momentum worldwide. However, there is little information on the most suitable rearing conditions for growth, development and survivorship of these flies, which is a prerequisite for mass production technologies. We evaluated the physiological requirements for growth and reproduction of H. illucens on two diets [spent grains supplemented with brewers' yeast (D1) and un-supplemented (D2)]. Development rates at nine constant temperatures (10-42°C) were fitted to temperature-dependent linear and non-linear day-degree models. Thereafter, life history table parameters were determined within a range of favourable temperatures. The thermal maximum (TM) estimates for larval, pre-pupal and pupal development using non-linear model ranged between 37.2 ± 0.3 and 44.0 ± 2.3°C. The non-linear and linear day-degree model estimations of lower developmental temperature threshold for larvae were 11.7 ± 0.9 and 12.3 ± 1.4°C for D1, and 10.4 ± 1.7 and 11.7 ± 3.0°C for D2, respectively. The estimated thermal constant of immature life stages development of BSF was higher for the larval stage (250±25 DD for D1 and 333±51 for D2) than the other stages evaluated. Final larval wet weight was higher on D1 compared to D2. The population growth rate was most favourable at 30-degree celsius (°C) with higher intrinsic rate of natural increase (rm = 0.127 for D1 and 0.122 for D2) and shorter doubling time (5.5 days for D1 and 5.7 days for D2) compared to the other temperatures. These results are valuable for the optimization of commercial mass rearing procedures of BSF under various environmental conditions and prediction of population dynamics patterns using computer simulation models.

The effect of assortative mixing on stability of low helminth transmission levels and on the impact of mass drug administration: Model explorations for onchocerciasis.

BACKGROUND: Stable low pre-control prevalences of helminth infection are not uncommon in field settings, yet it is poorly understood how such low levels can be sustained, thereby challenging efforts to model them. Disentangling possible facilitating mechanisms is important, since these may differently affect intervention impact. Here we explore the role of assortative (i.e. non-homogenous) mixing and exposure heterogeneity in helminth transmission, using onchocerciasis as an example. METHODOLOGY/PRINCIPAL FINDINGS: We extended the established individual-based model ONCHOSIM to allow for assortative mixing, assuming that individuals who are relatively more exposed to fly bites are more connected to each other than other individuals in the population as a result of differential exposure to a sub-population of blackflies. We used the model to investigate how transmission stability, equilibrium microfilarial (mf) prevalence and intensity, and impact of mass drug administration depend on the assumed degree of assortative mixing and exposure heterogeneity, for a typical rural population of about 400 individuals. The model clearly demonstrated that with homogeneous mixing and moderate levels of exposure heterogeneity, onchocerciasis could not be sustained below 35% mf prevalence. In contrast, assortative mixing stabilised onchocerciasis prevalence at levels as low as 8% mf prevalence. Increasing levels of assortative mixing significantly reduced the probability of interrupting transmission, given the same duration and coverage of mass drug administration. CONCLUSIONS/SIGNIFICANCE: Assortative mixing patterns are an important factor to explain stable low prevalence situations and are highly relevant for prospects of elimination. Their effect on the pre-control distribution of mf intensities in human populations is only detectable in settings with mf prevalences <30%, where high skin mf density in mf-positive people may be an indication of assortative mixing. Local spatial variation in larval infection intensity in the blackfly intermediate host may also be an indicator of assortative mixing.

Genetic variation in a colonization specialist, Simulium ruficorne (Diptera: Simuliidae), the world's most widely distributed black fly.

The ability of aquatic insects to colonize Earth's most remote freshwater habitats, such as those of islands and deserts, is limited to select taxa. Among black flies, the premiere colonization specialist is Simulium ruficorne Macquart, the only species known from both the Afrotropical and Palearctic regions. We investigated the cytogenetics of S. ruficorne to gain insight into its wide geographic distribution and ability to colonize oceanic islands and deserts. On the basis of larval polytene chromosomes from 14 locations, we documented 17 novel and previously known chromosomal rearrangements and established five cytoforms (A1, A2, B, C, and D), of which probably four (A1/A2, B, C, and D) are distinct species and two (A1 and A2) represent sex-chromosome polymorphism involving a heteroband in the long arm of chromosome III. The chromosome restructuring phenomena associated with the five cytoforms are consistent with the trend in the Simuliidae that one and the same rearrangement can assume different functions in the various descendants of a common ancestor in which the rearrangement was polymorphic. The most widely distributed cytoforms are A1 and A2, which are found in North Africa, the Canary Islands, and Majorca. Simulium ruficorne, the only known black fly in the Hoggar Mountains of the central Sahara Desert, represents a cohesive population of cytoform A1 little differentiated from other North African populations of A1 and A2. Cytoform B inhabits the West African mainland, cytoform C is on Tenerife, and cytoform D is on Cape Verde. We suggest that dispersal and colonization specialists, such as S. ruficorne, are multivoltine inhabitants of temporary streams, and must relocate as their habitats deteriorate. Simulium ruficorne, therefore, should have adaptations that contribute to successful dispersal and colonization, perhaps largely physiological in nature, such as tolerance of high temperatures and droughts.

Impact of pH and feeding system on black soldier fly (Hermetia illucens, L; Diptera: Stratiomyidae) larval development.

Black soldier fly (BSF) is a generalist species able to reduce large quantities of organic substrates and is thus considered as an interesting solution for waste management. Moreover, as BSF larvae accumulate high quantities of nutrients during their growth, they are valued because of their potential to produce products such as protein meal or fat for livestock feeds. Abiotic factors can influence larva growth, and a more detailed knowledge and control of these parameters can lead to the development of mass BSF breeding for the production of innovative products for animal feeds. As little information is available on the effects of the pH of substrates and feeding systems, the aim of this study was to evaluate the impact of these two factors on the activities of BSF larvae, prepupae, and adults. An experiment was performed with two fixed factors: i) pH (4.0; 6.1; 7.5; 9.5) and ii) feeding system (batch feeding system (TFS) or daily feeding system (DFS)). The pH treatments impacted larval weight on the first, third, and fifth day, but not at the end of the trial. Larval activity increased pH values from the fourth day onward, with final values of around 8.9-9.4 in all the treatments. The weight of the prepupae ranged from between 0.094 and 0.100 g. The final weight of the larvae and pupae, sex ratio, ingested food, larval mortality, percentage of emergence, and time to reach the pupa stadium were all affected by the feeding system. DFS showed the heaviest final larval weight (0.149 g), but required a longer time (11.3 d) than TFS to reach the prepupa stadium. The findings of this research could be useful for the mass production of BSF. Evaluation of an appropriate feeding system and initial pH value of the substrate are important parameters to reduce the time and to increase the weight in the production of larvae.

Cultivation of black soldier fly larvae on almond byproducts: impacts of aeration and moisture on larvae growth and composition.

BACKGROUND: The increasing production of almonds worldwide has resulted in the significant generation of byproduct streams that require end uses. One potential use for byproducts is for cultivation of additional food sources including insects. Studies were performed to determine if black soldier fly larvae (Hermetia illucens L.) could be cultivated on almond byproducts (hulls and shells) and to examine the effect of aeration and moisture on larvae growth and hull composition. RESULTS: Increasing aeration from 0.04 to 0.36 mL min-1 g dry weight-1 tripled the harvest weight of larvae and increased larvae yield by a factor of five. Larvae calcium content increased by 18% with an increase in aeration from 0.04 to 0.95 mL min-1 g dry weight-1 . Moisture content also affected harvest dry weight and yield; increasing moisture content from 480 g kg-1 (wet basis) to 680 g kg-1 increased harvest weight by 56% and yield by a factor of 2. Variables did not affect larvae methionine and cysteine content. Low moisture content and aeration rate yielded an environment that supported microbial consumption of hulls over larvae consumption and growth. CONCLUSIONS: The results demonstrate that almond hulls are a suitable feedstock for larvae production under controlled management of moisture content and aeration. © 2018 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Partial Dietary Inclusion of Hermetia illucens (Black Soldier Fly) Full-Fat Prepupae in Zebrafish Feed: Biometric, Histological, Biochemical, and Molecular Implications.

Due to minimal environmental impact, compared to most conventional feed commodities, insects deserve a growing attention as candidate ingredients for aquafeeds. This study tested, for the first time during zebrafish larval rearing, the effects of an increasing replacement (0%-25%-50%) of fish meal by black soldier fly (BSF) full-fat prepupae meal. All diets were formulated to be isonitrogenous and isolipidic. A multidisciplinary approach, including biometrics, histology, gas chromatography-mass spectrometry, and molecular analyses, was applied to better understand the biological responses of larval zebrafish to the different partial inclusions of BSF in the feed. Generally, results are promising, but a 50% of BSF meal inclusion in the diet affected both lipid composition and accumulation in the larvae.

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.

Distribution of black flies (Diptera: Simuliidae) along an elevational gradient in the Andes Mountains of Colombia during the El Niño Southern Oscillation.

Vector ecology is a key factor in understanding the transmission of disease agents, with each species having an optimal range of environmental requirements. Scarce data, however, are available for how interactions of local and broad-scale climate phenomena, such as seasonality and the El Niño Southern Oscillation (ENSO), affect simuliids. We, therefore, conducted an exploratory study to examine distribution patterns of species of Simuliidae along an elevational gradient of the Otún River in the Colombian Andes, encompassing four ecoregions. Larval and pupal simuliids were sampled at 52 sites ranging from 1800 to 4750 m above sea level in dry and wet seasons and during the La Niña phase (2011-2012) and the El Niño phase (2015-2016) of the ENSO; physicochemical measurements were taken during the El Niño phase. Twenty-seven species in two genera (Gigantodax and Simulium) were collected. Species richness and occurrence in each ecoregion were influenced by elevation, seasonality, and primarily the warm El Niño and cool La Niña phases of the ENSO. The degree of change differed among ecoregions and was related to physicochemical factors, mainly with stream discharge. Some putative simuliid vectors of Leucocytozoon, such as G. misitu and S. muiscorum, markedly changed in distribution and occurrence, potentially influencing parasite transmission.

Rearing Zebrafish on Black Soldier Fly (Hermetia illucens): Biometric, Histological, Spectroscopic, Biochemical, and Molecular Implications.

A desirable goal of the aquaculture sector is to replace most of fish meal and fish oil with more sustainable, cost-effective, and environmental friendly ingredients ensuring fish health and welfare standards. Due to minimal environmental impact, compared with most conventional feed commodities, insects deserve a growing attention as candidate ingredients for aquafeeds. The present study investigated, for the first time, the possible application of a 100% insect diet in zebrafish larval rearing. Through a multidisciplinary approach, the major biological responses of fish to the new diets were assessed. Results of biometry, fatty acid composition, expression of genes involved in fish growth, stress response, lipid metabolism, chitinolytic activity, gut inflammation, and liver macromolecular composition suggested a possible application of insect larvae for zebrafish larval rearing. However, further studies are necessary to better understand the use of this insect species in the rearing of fish.