Do grasshoppers prefer one species of lentil over another?

Non-Peer ReviewedSevere outbreaks of grasshoppers cause yield losses in many economically important crops. Lentil (Lens culinaris) is particularly susceptible to grasshopper damage. The weather patterns of 2001-2002 in most of the lentil production regions of Saskatchewan contributed to the outbreak in grasshopper populations resulting in major damage to the lentil crop. Grasshoppers preferentially target the flowers and young pods of lentil plants. Lentil plants, due to their indeterminate growth habit, will re-grow if moisture is available, leading to development of new pods, resulting in delayed maturity and further grasshopper damage. Pods that are damaged or not consumed entirely may shatter or not fill properly. Grasshoppers are known to have very specific feeding habits and may show a range of preference from one plant species to another based on taste or texture. One of the seven known species of lentil has hairy pods. Grasshopper feeding preferences were examined on five lentil species, including the cultivated lentil. The purpose was to determine if grasshoppers prefer to feed on the cultivated lentil compared to four wild species. If they do, it may be possible in future to breed lentil varieties that are less damaged by grasshoppers by using the wild lentil species in the breeding program

Peut-on utiliser des algues marines pour améliorer la qualité de l'eau des bassins d'exposition du Biodôme de Montréal?

Affiche présentée dans le cadre du Colloque de l'ARC, «La relève scientifique et la recherche collégiale : pratiques inspirantes au regard des chercheuses et chercheurs, et enjeux spécifiques à la formation des étudiantes et étudiants», dans le cadre du 84e Congrès de l'Acfas, Université du Québec à Montréal, Montréal, le 10 mai 2016.Dans les bassins d’eau recyclée du Biodôme de Montréal, le contrôle de l’azote et du phosphore dissous est essentiel, car leur accumulation peut dégrader la qualité de l’eau et devenir une source de stress pour les organismes aquatiques. Or, certaines algues marines ont la capacité d’absorber ces polluants tout en produisant de l’oxygène. L’objectif de notre  projet mené à l’École des pêches et de l’aquaculture du Québec était de développer un prototype de filtre biologique à base d’algues cultivées, efficace en termes d’absorption et de séquestration du nitrate et du phosphate dissous. Pour ce faire, les performances de deux espèces d’algues marines du golfe du Saint-Laurent, Palmaria palmata et Ulva lactuca, ont été évaluées dans des conditions similaires à celles des bassins du Biodôme de Montréal, soit deux températures (5 °C et 10 °C) et trois combinaisons de nutriments N-NO3- : P-PO43- (40:6, 50:7,5, 60:9 mg/L). Les résultats indiquent qu’aux densités testées (7 et 3 g AF/L; AF = algues fraîches), au bout de six jours, 10,2 ± 1,5 % du nitrate et 13,83 ± 9,0 % du phosphate présents dans l’eau ont été enlevés par P. palmata tandis que U. lactuca a enlevé 12,7 ± 3,3 % du nitrate et 13,01 ± 9,8 % du phosphate. La vitesse moyenne d’absorption journalière de l’azote par P. palmata était de 0,12 mg N/g AF  vs 0,34 mg N/g AF pour U. lactuca. Si les deux espèces montrent une bonne capacité d’épuration de l’eau, c’est U. lactuca qui absorbe l’azote le plus efficacement

Effects of killing methods on lipid oxidation, colour and microbial load of black soldier fly (Hermetia illucens) larvae

The projected global population growth by 2050 will require an increase in the production of high-quality food. Insects represent a promising alternative ingredient for feed with a lower environmental impact than conventional livestock such as poultry, swine and bovine species. In a context of commercial-scale production and considering the great diversity of insects, it is crucial to optimize the processing steps, including those used to kill insects. In addition to being able to maximize the nutritional and microbiological quality of the final product, insect killing methods should be rapid and effective. This project aims to optimize killing methods, i.e., blanching, desiccation, freezing (−20 °C; −40 °C; liquid nitrogen), high hydrostatic pressure, grinding and asphyxiation (CO2; N2; vacuum conditioning), and to evaluate their impact on the composition, lipid oxidation, colour and microbiological quality on the black soldier fly larvae. Blanching appears to be the most appropriate strategy since it is a rapid and effective killing method reducing larval moisture while minimizing lipid oxidation, microbial contamination and colour alteration. Ultimately, this work will help to establish a standardized protocol that meets the Canadian regulatory quality requirements for feed. Abstract : Black soldier fly (BSF) larvae represent a promising alternative ingredient for animal feed. Post-production processing can, however, affect their quality. This project aimed to optimize larval killing by comparing the effects on the nutritional and microbiological quality of 10 methods, i.e., blanching (B = 40 s), desiccation (D = 60 °C, 30 min), freezing (F20 = −20 °C, 1 h; F40 = −40 °C, 1 h; N = liquid nitrogen, 40 s), high hydrostatic pressure (HHP = 3 min, 600 MPa), grinding (G = 2 min) and asphyxiation (CO2 = 120 h; N2 = 144 h; vacuum conditioning, V = 120 h). Some methods affected the pH (B, asphyxiation), total moisture (B, asphyxiation and D) and ash contents (B, p < 0.001). The lipid content (asphyxiation) and their oxidation levels (B, asphyxiation and D) were also affected (p < 0.001). Killing methods altered the larvae colour during freeze-drying and in the final product. Blanching appears to be the most appropriate strategy since it minimizes lipid oxidation (primary = 4.6 ± 0.7 mg cumen hydroperoxide (CHP) equivalents/kg; secondary = 1.0 ± 0.1 mg malondialdehyde/kg), reduces microbial contamination and initiates dehydration (water content = 78.1 ± 1.0%). We propose herein, an optimized protocol to kill BSF that meet the Canadian regulatory requirements of the insect production and processing industry

Comparison of black soldier fly larvae pre-treatments and drying techniques on the microbial load and physico-chemical characteristics

Black soldier fly larvae (BSFL) are good candidates for upcycling wet organic residuals. Like other unprocessed raw animal products, BSFL require processing to prevent spoilage and degradation during storage and to facilitate their use as feed ingredients. In this study, hot-air drying and freeze-drying were examined as means to ensure long-term preservation. Pre-treatments of larvae, such as puncturing, blanching (40 s) and scalding (2, 4, 6 and 8 min) in boiling water reduced drying times, most likely by affecting the integrity of the wax-coated cuticle that protects the larvae against desiccation. Overall, the larvae dried two to six times faster using hot-air compared to freeze-drying, and larvae pre-treatments were proven to effectively improve drying efficacy. Pre-treating larvae in boiling water followed by a shorter drying time with hot air was effective at reducing primary and secondary oxidation as well as darkening/browning (colour lightness, L* value) compared to the untreated control (rawthawed) larvae. The larvae pre-treatments in boiling water also led to a significant reduction in microbial load (3.21 to 4.83 log) in the dry product compared to the control. BSFL powder, produced from grinding thawed larvae that were pre-treated for 4 min in boiling water before being dried in hot air (60 °C; 6 h), had a water activity below 0.4. This led to a relatively stable product with limited colour changes over a 30-day storage period. These processing treatments also resulted in a product with no detectable Salmonella and Escherichia coli counts ranging from 100 to 1000 cfu/g. Overall, the powdered BSFL product was deemed suitable to incorporate into pelleted feed under the current regulations in Canada

Effect of similar feeding regime on growth and body composition of Indian major carps (Catla catla, Cirrhinus mrigala and Labeo rohita) under mono and polyculture

Growth performance and body composition of yearling Indian major carps (Catla catla, Cirrhinus mrigala and Labeo rohita) was evaluated in semi-intensive (mono and polyculture) systems for 90 days. Prior to stocking, all ponds were fertilized with organic and inorganic manures. This application was repeated every two weeks throughout the study period. Supplementary feed containing 35% protein was applied daily at 3% of wet body weight. In trial 1, all the three species gained significantly higher weights with experimental feed (F1) versus control group (F0). There was non-significant difference observed among species. In trial 2, non-significant difference was observed for net weight gain among species and between feeds. The feed conversion ratio (FCR), protein efficiency ratio (PER), protein utilization (PU), gross nitrogen retention efficiency (GNRE%) and gross energy retention efficiency (GERE%) were found non-significantly different among species in both trials, except GNRE% in polyculture, where L. rohita showed significantly higher values than its counterparts. No significant difference was observed in body composition and mineral contents among species and between feeds in both trials. In conclusion, all the three fish species performed well under monoculture system with 35% protein diet and showed significantly higher growth than the control, compared to polyculture, without any significant effect on body composition.Keywords: Artificial feed, Indian major carps, growth, proximate composition, nutrient retention efficiency, cost effectivenes

Microbiota is structured by gut regions, life stage, and diet in the Black Soldier Fly (Hermetia illucens)

The larvae of the Black Soldier Fly (Hermetia illucens) provide numerous ecological benefits, leading to significant commercial advancements. These benefits include the bioconversion of low-value waste into high-value feed and soil amendments. Understanding how the bacterial and eukaryotic microbiota communities affect host performance becomes vital for the optimization and specialization of industrial-scale rearing. This study investigates H. illucens-associated microbiota taxonomic composition and dynamics across the developmental cycle (eggs, neonates, larvae, prepupae, and imago X0 to second generation X1) when reared on two substrates: (i) plant-based (Housefly Gainesville diet) and (ii) animal-based (poultry hatchery waste). By using the 16S gene amplicon metataxonomic approach, we found that the results revealed that bacterial microbiota inherited from parents reared on a different substrate may have induced dysbiosis in the progeny. Specifically, the interaction networks of individuals reared on hatchery waste showed a high prevalence of negative interactions and low connectivity. Proteobacteria (39–92%), Firmicutes (4–39%), Bacteroidota (1–38%), and Actinobacteria (1–33%). In animal feed-reared individuals, Firmicutes reached the highest relative abundance (10–80%), followed by Proteobacteria (6–55%), Actinobacteria (1–31%), and Bacteroidota (0–22%). The rearing substrate was the main driver of microbiota composition, while the developmental stage influenced only the whole individual's bacterial microbiota composition. Gut regions were associated with distinct bacterial composition and richness, with diversity decreasing along the digestive tract. For the first time, microeukaryotes of the microbiota other than Fungi were investigated using 18S genetic marker amplicon sequencing with novel blocking primers specific to the Black Soldier Fly. Microeukaryotes are a neglected part of multitrophic microbiota communities that can have similar effects on their hosts as bacterial microbiota. Microeukaryotes from seven orders were identified in black soldier flies, including potential pathogens (e.g., Aplicomplexa group). Nucletmycea were the dominant class throughout development, followed by Holozoa and Stramenophiles. The eukaryote microbiota was structured by developmental stages but not by gut regions. Insights from this study are a stepping stone toward the microbiological optimization of black soldier flies for industrial rearing, highlighting how a synthetic microbiota assembly should be tailored to the rearing environment of the larvae at a targeted developmental stage

Novel Feed from Invasive Species is Beneficial to Walleye Aquaculture

Carnivorous fishes, such as the Walleye Sander vitreus, are nutritionally demanding for fish meal. A promising alternative to marine-origin fish meal, the supply of which has been stagnant in recent decades, is fish meal derived from undesirable freshwater species, such as the White Sucker Catostomus commersonii. To evaluate the relative value of such ingredients, we examined the growth performance of Walleye juveniles. Two dietary treatments were tested: an experimental (EXP) diet that was manufactured using White Sucker as fish meal in comparison with a commercial (COM) diet, EWOS Micro (EWOS Canada, Ltd.). Dietary lipid content was 15.1% and 16.8% for EXP and COM diets, respectively. The protein content was 50.4% and 57.6% for EXP and COM diets, respectively. The energy content was 5,098.76 ± 9.23 cal/g (mean ± SD) for the EXP diet and 5,134.47 ± 10.95 cal/g for the COM diet. Starting at 27 d posthatch, Walleye juveniles (initial weight [mean ± SD] = 0.03 ± 0.008 g; initial length = 15.7 ± 1.5 mm) were reared for 6 weeks in three replicate tanks for each treatment. Condition factor (0.83), final weight (1.12 ± 0.3 g), and weight gain (1.09 ± 0.06 g) were higher in fish that were fed the EXP diet. Similarly, the energetic lipid content of fish in the EXP treatment group (mean ± SD = 5.01 ± 0.45 g/kg) was also higher than that of fish fed the COM diet (3.30 ± 0.53 g/kg). Although the polar lipid content (membrane lipids) was similar in fish from the two treatments, the nutritional ratio for COM juveniles was over 1.5 for arachidonic acid and docosahexaenoic acid, indicating selective incorporation by juveniles and suggesting a potential dietary imbalance of these fatty acids. Furthermore, the higher observed selective incorporation of oleic acid in juveniles fed the EXP diet suggested that a higher value of this fatty acid in the EXP feed could have increased Walleye growth performance. Threonine was the main essential amino acid (AA; >18.5% of total AAs), while serine and glycine contributed the highest percentages of the nonessential AAs (>31% and 8.5% of total AAs, respectively). All three AAs, often considered limiting ingredients, are important to support growth and are involved in metabolic processes in some fish species. Our results demonstrate that feed pellets made with White Sucker fish meal improved growth in Walleye juveniles and can serve as a suitable and probably lower-cost regional alternative to marine fish meal in feeds for carnivorous fishes

In situ chelation of phosphorus using microencapsulated aluminum and iron sulfate to bind intestinal phosphorus in rainbow trout (Oncorhynchus mykiss)

Excess phosphorus (P) in freshwater ecosystems increases primary production which, left uncontrolled, may lead to eutrophication, accelerating the ageing process of receiving water bodies. To limit phosphorus release resulting from freshwater aquaculture, we propose to incorporate microencapsulated P-chelating agents into fish diets. In a first trial, alum (Al2SO4) and ferrous sulfate (FeSO4) were encapsulated by spray-chilling in a hydrogenated lipid matrix. Two practical diets incorporating one of these two chelating elements (6 g/kg) were fed to fish for five weeks (w), and P release from resulting feces was compared. In a second trial, a similar approach was used to evaluate the impact of increasing supplementation of encapsulated alum (3, 6, 15 g/kg of diet). Feces from the fish fed with the diets incorporating alum and ferrous sulfate released 62 % and 54 % respectively less P than feces from fish fed with control diets. The second experiment revealed a negative correlation between the level of encapsulated Al2SO4 included in the diet and phosphorus released by the feces (y = 0.18x2 ˗ 4.78x + 62.7; R2 = 0.93). Feces from feed incorporating Al2SO4 at 0, 3, 6 and 15 g/kg released 62 %, 52 %, 39 %, and 32 % of the total fecal P after 14 days respectively. Fish fed encapsulated Al2SO4 have similar growth performance and mineral status. Incorporation of encapsulated P-chelating agents into fish feed offers an opportunity to manage P release from fish feces. Long-term feeding studies are required for validation of dietary Al2SO4 and FeSO4 impacts on potential toxicity and growth/environmental performance following chronic feeding of encapulated P chelating agents

Prokineticin 1 induces Dickkopf 1 expression and regulates cell proliferation and decidualization in the human endometrium

Prokineticin 1 (PROK1) signalling via prokineticin receptor 1 (PROKR1) regulates the expression of several genes with important roles in endometrial receptivity and implantation. This study investigated PROK1 regulation of Dickkopf 1 (DKK1) expression, a negative regulator of canonical Wnt signalling, and its function in the non-pregnant endometrium and first trimester decidua. DKK1 mRNA expression is elevated during the mid-secretory phase of the menstrual cycle and expression increases further in first trimester decidua. DKK1 protein expression is localized to glandular epithelial and stromal cells during the proliferative, early- and mid-secretory phases, whereas expression is confined to the stroma in the late-secretory phase and first trimester decidua. PROK1 induces the expression of DKK1 in endometrial epithelial cells stably expressing PROKR1 and in first trimester decidua explants, via a Gq-calcium-calcineurin-nuclear factor of activated T-cells-mediated pathway. Endometrial epithelial cell proliferation is negatively regulated by PROK1-PROKR1 signalling. We demonstrate that this effect on cell proliferation occurs via DKK1 expression, as siRNA targeted against DKK1 reduces the PROK1-induced decrease in proliferation. Furthermore, decidualization of primary human endometrial stromal cells with progesterone and cyclic adenosine monophosphate is inhibited by miRNA knock down of PROK1 or DKK1. These data demonstrate important roles for PROK1 and DKK1 during endometrial receptivity and early pregnancy, which include regulation of endometrial cell proliferation and decidualization

Assessing the Impact of Automatic vs. Controlled Rotations on Spatial Transfer with a Joystick and a Walking Interface in VR

Part 1: Long and Short PapersInternational audienceWe present a user study assessing spatial transfer in a 3D navigation task, with two different motor activities: a minimal (joystick) and an extensive motor activity (walking Interface), with rotations of the viewpoint either controlled by the user, or automatically managed by the system. The task consisted in learning a virtual path of a 3D model of a real city, with either one of these four conditions: Joystick / Treadmill Vs Manual Rotation / Automatic Rotation. We assessed spatial knowledge with six spatial restitution tasks. To assess the interfaces used, we analyzed also the interaction data acquired during the learning path. Our results show that the direct control of rotations has different effects, depending on the motor activity required by the input modality. The quality of spatial representation increases with the Treadmill when rotations are enabled. With the Joystick, controlling the rotations affect spatial representations. We discuss our findings in terms of cognitive, sensorimotor processes and human computer interaction issues