Growth efficiency,intestinal biology,and nutrient utilization and requirements of black soldier fly(Hermetia illucens)larvae compared to monogastric livestock species:a review

In recent years,interest in the larvae of black soldier fly(BSF)(Hermetia illucens)as a sustainable protein resource for livestock feed has increased considerably.However,knowledge on the nutritional and physiological aspects of this insect,especially compared to other conventional farmed animals is scarce.This review presents a critical comparison of data on the growth potential and efficiency of the BSF larvae(BSFL)compared to conventional monogastric livestock species.Advantages of BSFL over other monogastric livestock species includes their high growth rate and their ability to convert low-grade organic waste into high-quality protein and fat-rich biomass suitable for use in animal feed.Calculations using literature data suggest that BSFL are more efficient than broilers,pigs and fish in terms of conversion of substrate protein into body mass,but less efficient than broilers and fish in utilization of substrate gross energy to gain body mass.BSFL growth efficiency varies greatly depending on the nutrient quality of their dietary substrates.This might be associated with the function of their gastrointestinal tract,including the activity of digestive enzymes,the substrate particle characteristics,and their intestinal microbial community.The conceived advantage of BSFL having an environmental footprint better than conventional livestock is only true if BSFL is produced on low-grade organic waste and its protein would directly be used for human consumption.Therefore,their potential role as a new species to better close nutrient cycles in agro-ecological systems needs to be reconsidered,and we conclude that BSFL is a complementary livestock species efficiently utilizing organic waste that cannot be utilized by other livestock.In addition,we provide comparative insight into morpho-functional aspects of the gut,characterization of digestive enzymes,gut microbiota and fiber digestion.Finally,current knowledge on the nutritional utilization and requirements of BSFL in terms of macro-and micronutrients is reviewed and found to be rather limited.In addition,the research methods to determine nutritional requirements of conventional livestock are not applicable for BSFL.Thus,there is a great need for research on the nutrient requirements of BSFL.

Black soldier fly:A new vista for livestock and poultry manure management

The number of intensive livestock and poultry farms is expected to increase substantially in future because of consumer demand.Unfortunately,such demand also results in a great deal of manure being generated,which threatens the environment if it is not properly managed.Concurrent developments in biotransformation of these wastes with the black soldier fly(BSF),Hermetia illucens(L.)(Diptera:Stratiomydiae),demonstrates such concerns can be abated,while also producing products(e.g.,protein,chitin,biodiesel,and fertilizer)of value.In this review,we analyzed the factors influencing black soldier fly larvae(BSFL)conversion processes,the role of microorganisms,and the mechanisms used by BSFL when converting livestock and poultry manure into these valuable products.The effects of BSFL conversion technology on reducing the hazards of such materials and their associated pathogens are reviewed,and the economics of livestock and poultry manure conversion by BSF larvae is discussed.

Changes in speciation,mobility and bioavailability of Cd,Cr and As during the transformation process of pig manure by black soldier fly larvae(Hermetia illucens)

The black soldier fly larvae(BSFL)(Hermetia illucens)are a good candidate for poultry and livestock manure treatment.The harvested insect bodies and feces can be used as animal feed and organic fertilizer.However,heavy metals have a negative impact on the transformation process of the manure by BSFL.Here we evaluated the effects of Cd,Cr and As in pig manure on the growth of BSFL,as well as the mobility and changes in speciation of the metals during the transformation process.The results showed that As significantly reduced the weight of BSFL,but Cr and Cd had no significant effects on BSFL growth.The bioaccumulation factors(BAFs)at various concentrations of Cd(2.8–3.7)were significantly higher than those of Cr(0.44–0.62)and As(0.43–0.45).The heavy metals in pig manure were mainly transferred to BSFL feces,and the distribution percentages of Cd,Cr and As in the BSFL feces were 52.6–62.0%,90.3–94.2%and 93.0–93.3%,respectively.Cd concentrations in BSFL feces were significantly lower than those in the pig manure,while there were no significant differences in the concentrations of Cr and As between BSFL feces and pig manure(except for the treatment with the addition of 150 mg Cr kg^(–1)).The metal speciation(weak acid soluble,reducible,oxidizable and residual fractions)in BSFL feces obviously changed when compared with pig manure.In BSFL feces,the reducible proportion of Cr decreased while the oxidizable proportion increased.Cd mainly existed in the weak acid soluble and reducible states in pig manure and BSFL feces.For As,the proportions of weak acid soluble and reducible states decreased in BSFL feces.After the BSFL transformation process,the bioavailable fraction of Cr decreased by 17.3–23.1%,but those of Cd and As did not change significantly,except for As in the CK group.These findings contribute to our understanding of the roles of BSFL during the biotransformation process of livestock manure as well as the safe utilization of transformed products.

The Performance of Black Soldier Fly Larvae (BSFLs), Hermetia illucens L. (Diptera: Stratiomyidae), as a Function of the Substrate Used: A Review

Organic wastes are one of the greatest challenges that cities face worldwide. In numerous underdeveloped nations, like Cameroon, waste is often disposed of through landfills, composting, or open-air combustion. Unfortunately, the concept of waste sorting and organic waste processing is new to many individuals. This has led to an increase in the amount of organic waste and the costs connected with its management. Consequently, the majority of developing nations have sought out waste management solutions that are more cost-effective. Therefore, it has been determined that the bioconversion of organic wastes by black soldier fly larvae (BSFLs) (Hermetia illucens) into multifunctional prepupae is a viable alternative. Appreciation is given to the employment of the organic waste management approach in developing nations since it is not only environmentally friendly and economically viable, but also provides a means for waste valorisation through the production of diverse resources and potential economic benefits. Studies have proved the usefulness of the insect in controlling organic wastes, but countries such as Cameroon are still unfamiliar with the nuances of this method. Consequently, this timely review examined the performance of the BSFL, specifically in organic waste treatment, as well as the best practices for multiplying them to determine its viability for use in a waste treatment plant, the production of high-quality larvae as a source of protein for livestock, and the production of diesel fuel.

Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility,apparent metabolizable energy and apparent ileal amino acid digestibility

Background: The study aimed to determine the apparent total tract digestibility coefficients(ATTDC) of nutrients, the apparent metabolizable energy(AME and AMEn) and the amino acid(AA) apparent ileal digestibility coefficients(AIDC)of a partially defatted(BSFp) and a highly defatted(BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg(w/w) of the basal diet with BSFp or BSFh, respectively.Results: Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly(P < 0.05) different between the two BSF meals, with higher levels for BSFp(16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility(0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal(P < 0.05).Conclusions: Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

Evaluation of growth performance,feed efficiency and nutrient digestibility of red hybrid tilapia fed dietary inclusion of black soldier fly larvae(Hermetia illucens)

Insects,particularly black soldier fly larvae(BSFM),Hermetia illucens,have been regarded as promising protein and lipid sources in animal feed,including fish.Digestibility is the key factor that affects nutrient utilization,feeding physiology and efficiency.In the present work,the effect of BSFM on the digestibility of red hybrid tilapia(RHT)compared to fish meal(FM)was ultimately unveiled.A 56-day growth trial was performed with 60 RHT(~30 g)randomly distributed into six tanks and fed two experimental diets containing FM as a reference diet and BSFM as a test diet.In addition,faeces were collected to determine their chromium concentration and proximate composition.The apparent digestibility coefficient(ADC)of dry matter,crude protein and energy in the BSFM diet were observed to be significantly higher than those in the FM diet.Besides,the growth performance of fish fed with the BSFM diet exhibited significantly higher(P<0.05)weight gain,specific growth rate,protein efficiency ratio and lower feed conversion ratio than those in the FM group.This study shows that the BSFM feed was well digested by tilapia and improved its growth performance.

Dietary black soldier fly oil enhances growth performance,flesh quality,and health status of largemouth bass(Micropterus salmoides)

The study aimed to assess the effects of dietary black soldier fly oil(BSFO)on the growth performance,flesh quality,and health status of largemouth bass(Micropterus salmoides).Six iso-nitrogenous and isolipid diets were formulated by substituting fish oil and soybean oil(1/2,wt/wt)with BSFO in percentages of 0%,20%,40%,60%,80%,and 100%,respectively.The diets were fed to 960 fish(initial body weight=16.5 g)in four replicates for 8 weeks.Indicators related to growth performance,body composition,hematology,flesh quality,expression of genes related to inflammatory cytokines and apoptosis,and the response of fish to Aeromonas veronii challenge were analyzed.The results showed that the weight gain rate was numerically improved in all BSFO substitution groups,ranging from 9.3%to 44.0%compared to the control group.The highest survival rate and the lowest hepatosomatic index and condition factor were observed in the BFSO20 group.In terms of flesh quality,the water-holding capacity of the dorsal muscle was elevated with higher levels of dietary BSFO.However,significant changes in texture properties(cohesiveness,gluing,and chewiness)were observed in the BSFO20 group(P<0.05).Six hematological parameters related to glycolipid and liver function were optimized in most of the BFSO substitution groups.Furthermore,the expressions of six inflammation-and apoptosis-related genes(IL-1β,Bcl-xl,BAX,caspase8,TNF-α,and IL-10)were significantly affected by dietary BSFO(P<0.05).Following bacterial challenge,the seven-day cumulative survival rates of fish were considerably increased from 10.0%in the control group to 60.0%and 66.7%in the BSFO80 and BSFO100 groups,respectively.One-variable linear regression analysis revealed that various parameters related to fish growth,flesh quality,and health status were significantly influenced by dietary BSFO substitution levels in a dose-dependent manner(P<0.05).In conclusion,substituting around 20%of dietary fish oil and soybean oil with BSFO is promising in improving the growth performance and flesh quality of M.salmoides.However,to enhance immunity and disease resistance,it is recommended to further increase the inclusion of BSFO in the diet.

Copper stimulates the incidence of antibiotic resistance, metal resistance and potential pathogens in the gut of black soldier fly larvae

The black soldier fly larvae(BSFL) have been successfully applied to treat various organic wastes.However, the impacts of heavy metals on antibiotic resistance in the BSFL guts are poorly understood.Here, we investigated the effect of copper(exposure concentrations of 0, 100 and 800 mg/kg) on the antibiotic and metal resistance profiles in BSFL guts.A total of 83 antibiotic resistance genes(ARGs), 18 mobile genetic elements(MGEs) and 6 metal resistance genes(MRGs) were observed in larval gut samples.Exposure to Cu remarkably reduced the diversity of ARGs and MGEs, but significantly enhanced the abundances of gut-associated ARGs and MRGs.The levels of MRGs copA, czcA and pbrT were dramatically strengthened after Cu exposure as compared with CK(increased by 2.8–13.5 times).Genera Enterococcus acted as the most predominant potential host of multiple ARG, MGE and MRG subtypes.Meanwhile, high exposure to Cu aggravated the enrichment of potential pathogens in BSFL guts, especially for Escherichia, Enterococcus and Salmonella species.The mantel test and procrustes analysis revealed that the gut microbial communities could be a key determinant for antibiotic and metal resistance.However, no significant positive links were observed between MGEs and ARGs or MRGs, possibly suggesting that MGEs did not play a crucial role in shaping the ARGs or MRGs in BSFL guts under the stress of Cu.These findings extend our understanding on the impact of heavy metals on the gut-associated antibiotic and metal resistome of BSFL.

Improvement in bioconversion efficiency and reduction of ammonia emission by introduction of fruit fermentation broth in a black soldier fly larvae and kitchen waste conversion system

The black soldier fly(BSF),Hermetia illucens(Diptera:Stratiomyidae),is an insect commonly used for the bioconversion of various organic wastes.Not only can the BSF convert organic waste into macromolecular organic substances,such as insect pro-teins,but it can also lessen the pollution associated with these waste products by reducing ammonia emissions,for example.In this study,we measured the effects of adding fruit fermentation broth(Fer)and commercial lactic acid bacteria fermentation broth(Em)to kitchen waste(KW),as deodorizing auxiliary substances,on the growth performance of black soldier fly larvae(BSFL),the intestinal flora structure of BSFL,the ammonia emis-sion from the KW substrate,and the microbial community structure of the KW substrate.We found that the addition of Fer or Em increased the body weight of BSFL after 6 d of culture,increasing the growth rate by 9.96%and 7.96%,respectively.The addition of Fer not only reduced the pH of the KW substrate but also increased the relative abundance of probiotics,such as Lactobacillus,Lysinibacillus,and Vagococcus,which inhibited the growth of ammonifiers such as Bacillus,Oligella,Paenalcaligenes,Paenibacillus,Pseu-dogracilibacillus,and Pseudomonas,resulting in the reduction of ammonia emission in the KW substrate.Moreover,the addition of Fer or Em significantly increased the rela-tive abundances of Bacteroides,Campylobacter,Dysgonomonas,Enterococcus,and Ig-natzschineria in the gut of BSFL and increased the species diversity and richness in the K W substrate.Our findings provide a novel way to improve the conversion rate of organic waste and reduce the environmental pollution caused by BSF.

Endogenous chitinase might lead to differences in growth performance and intestinal health of piglets fed different levels of black soldier fly larva meal

This study aimed to investigate the effects of different levels of black soldier fly(BSF)replacing soybean meal(SBM)in diets on the performance and health condition of piglets.A total of 180 weaned piglets were allocated into 5 treatments:BSF0(corn-soybean meal basal diet),BSF25(BSF replacing 25%SBM),BSF50(BSF replacing 50%SBM),BSF75(BSF replacing 75%SBM)and BSF100(BSF replacing 100%SBM).During the whole period,in comparison with BSF0,average daily gain(ADG)and average daily feed intake increased in the BSF25 and BSF50 groups,whereas ADG decreased in the BSF75 and BSF100groups(P<0.05).The result of quadratic fitting curve showed that piglets exhibited the highest ADG when BSF replaced around 20%SBM.Compared with BSF0,organic matter and dry matter digestibility improved in the BSF25 group,whereas ether extract digestibility decreased in the BSF100 group(P<0.05).In comparison with BSF0,piglets from the BSF25 group showed a higher duodenal ratio of villus height to crypt depth,increased jejunal sucrase activity,serum neuropeptide Y and ghrelin levels,elevated ileal immunoglobulin(Ig)A,Ig G and Ig M contents and a lower leptin level,and piglets from the BSF100 group exhibited an increased relative weight of kidney(P<0.05).However,no significant differences were observed in the expression level of tight junction proteins and chitin-degrading enzyme.Additionally,compared with BSF0,the abundance of short chain fatty acid producing bacteria such as Ruminococcaceae,Faecalibacterium and Butyricicoccus increased,and potential pathogenic bacteria decreased in piglets from the BSF25 group,whereas piglets from the BSF100 group had a greater abundance of harmful bacteria.In conclusion,BSF replacing 25%SBM in diets could improve digestive parameters,immune function and intestinal microbiota,and thus improved growth performance of piglets.However,BSF replacing 100%SBM showed an adverse effect on piglet performance,and the reason might be related to the limited amount of chitin-degrading enzyme.

Assessment of black soldier fly(Hermetia illucens)larvae meal as a potential substitute for soybean meal on growth performance and flesh quality of grass carp Ctenopharyngodon idellus

A 90-day feeding trial was conducted to assess the effects of black soldier fly larvae meal(BSFLM)as a replacement for soybean meal(SM)on growth performance and flesh quality of grass carp.A total of 420grass carp(299.93±0.85 g)were randomly divided into 7 groups(triplicate)and fed 7 diets with SM substitution of 0%(SM,control),15%(BSFLM15),30%(BSFLM30),45%(BSFLM45),60%(BSFLM60),75%(BSFLM75)and 100%(BSFLM100)by BSFLM.The growth performance of grass carp in the BSFLM75 and BSFLM100 groups were significantly lower compared to other groups(P<0.05).The mid-gut villus height was the lowest in the BSFLM100 group(P<0.05).Muscle nutritional value was improved due to increased DHA(docosahexaenoic acid),EPA(eicosapentaenoic acid),total HUFA(highly unsaturated fatty acids)and glycine levels,and reached the optimum in the BSFLM100 group(P<0.05).According to the results of principal component analysis and weight analysis of muscle texture and body color,all the BSFLM diets except BSFLM15 could improve muscle texture and body color and reached the optimum level in the BSFLM100 group.Muscle drip loss and hypoxanthine content were the lowest and muscle antioxidant capacity was the highest in the BSFLM75 group,and water-and salt-soluble protein contents reached the optimum level in the BSFLM60 group(P<0.05).Dietary BSFLM significantly reduced muscle fiber area and diameter,and increased muscle fiber density and the proportion of small fiber(diameter<20μm)(P<0.05).Additionally,sarcomere lengths in the BSFLM75 and BSFLM100 groups were significantly higher than that in the SM group(P<0.05).The m RNA relative expression levels of Myo D,Myf5,My HC and FGF6b were remarkably up-regulated at an appropriate dietary BSFLM level(P<0.05).In conclusion,BSFLM could replace up to 60%SM without an adverse effect on growth performance and improve the flesh quality of grass carp.The optimum levels of dietary BSFLM were 71.0 and 69.1 g/kg diet based on the final body weight and feed conversion ratio.The flesh quality was optimal when dietary SM was completely replaced with BSFLM(227 g/kg diet).

Characterization and mode of action analysis of black soldier fly(Hermetia illucens)larva-derived hemocytes

With the growing importance of the black soldier fly(Hermetia illucens)for both sustainable food production and waste management as well as for science,a great demand of understanding its immune system arises.Here,we present the first description of the circulating larval hemocytes with special emphasis on uptake of microorganisms and distinguishing hemocyte types.With histological,zymographic,and cytometric methods and with a set of hemocyte binding lectins and antibodies,the hemocytes of H.illucens are identified as plasmatocytes,crystal cells,and putative prohemocytes.Total hemocyte counts(THC)are determined,and methods for THC determination are compared.Approximately 1100 hemocytes per microliter hemolymph are present in naive animals,while hemocyte density decreases dramatically shortly after wounding,indicating a role of hemocytes in response to wounding(and immune response in general).The determination of the relative abundance of each hemocyte type(differential hemocyte count,DHC)revealed that plasmatocytes are highly abundant,whereas prohemocytes and crystal cells make up only a small percentage of the circulating cells.Plasmatocytes are not only the most abundant but also the professional phagocytes in H.illucens.They rapidly engulf and take up bacteria both in vivo and in vitro,indicating a very potent cellular defense against invading pathogens.Larger bioparticles such as yeasts are also removed from circulation by phagocytosis,but slower than bacteria.This is the first analysis of the potent cellular immune response in the black soldier fly,and a first toolbox that helps to identify hemocyte(types)is presented.

Establishment of highly efficient transgenic system for black soldier fly(Hermetia illucens)

The black soldier fly(BSF),Hermetia illucens,is a promising insect for miti-gating solid waste problems as its larvae are able to bioconvert organic waste into valuable biomass.We recently reported a high-quality genome assembly of the BSF;analysis of this genome sequence will further the understanding of insect biology and identify genes that can be manipulated to improve efficiency of bioconversion.To enable genetic manip-ulation of the BSF,we have established the first transgenic methods for this economically important insect.We cloned and identified the ubiquitous actin5C promoter(Hiactin5C-p3k)and 3 endogenous U6 promoters(HiU6:1,HiU6:2,and HiU6:3).The Hiactin5C pro-moter was used to drive expression of a hyperactive variant of the piggyBac transposase,which exhibited up to 6-fold improvement in transformation rate when compared to the wild-type transposase.Furthermore,we evaluated the 3 HiU6 promoters using this trans-genic system.HiU6:1 and HiU6:2 promoters provided the highest knockdown efficiency with RNAi and are thus promising candidates for future Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)development.Overall,our findings provide valuable genetic engineering toolkits for basic research and genetic manipulation of the BSF.

Evaluation of Nutritional Value and Safety of Black Soldier Flies Fed on Dead Pig Meat and Bone Meal

[Objectives]This study was conducted to evaluate the nutritional value and safety of black soldier flies fed with dead pig meat and bone meal(DPMBM)and to explore the resource utilization of DPMBM.[Methods]The general nutrient composition,amino acids,fatty acids and mineral elements of black soldier fly meal(BSLM)were detected and analyzed.[Results]The results showed that the contents of moisture,crude protein,crude fat and ash in BSLM were 3.42%,42.31%,34.04%and 5.40%,respectively.The contents of total amino acids(TAA),essential amino acids(∑EAA)and non-essential amino acids(∑NEAA)and umami amino acids(∑DAA),the EAA/TAA value and the EAA/NEAA value were 37.93%,13.08%,24.85%,13.43%,34.47%,52.61%,respectively.A total of eight kinds of saturated fatty acids and seven kinds of unsaturated fatty acids were detected,accounting for 63.65%and 32.67%of the total fatty acids.Among the major mineral elements,the content of Ca was the highest,followed by K,Mg and Na.Among the trace mineral elements,the content of Mn was the highest,followed by Fe,Zn,Cu,Ni,Cr,Cd,As,Pb,Se,Sn,Ti,Sb and Hg.The contents of heavy metal mineral elements in BSLM were far lower than the limits specified in Hygienical Standard for Feeds.[Conclusions]In conclusion,BSLM has high nutritional value and good safety of heavy metals,and thus great potential for development and utilization as a high quality dietary protein,fat and mineral elements source.

黑水虻处理城镇污泥和餐厨垃圾的性能评价

利用黑水虻处理不同比例的城镇污泥和餐厨垃圾混合物,考察黑水虻幼虫生长发育状况,研究黑水虻对城镇污泥和餐厨垃圾的处理效果并通过测定黑水虻虫粪重金属含量进行安全性评价.结果表明,黑水虻处理城镇污泥和餐厨垃圾的幼虫存活率均大于93%;黑水虻干重(189~299g)随着城镇污泥比例的增加而降低;黑水虻虫体粗脂肪含量为7.73%~26.81%,蛋白质含量为22.80%~36.65%.黑水虻处理城镇污泥和餐厨垃圾减量率超过57%,幼虫生物量为13.8%~23.9%;虫粪有机质含量为60.86%~95.22%,N、P、K总养分含量为4.20%~6.58%;黑水虻处理后其粪便中Cr、Cd、As、Pb、Cu重金属元素含量降低,表明黑水虻粪便具有较大的肥料化利用价值.黑水虻处理技术可实现城镇污泥和餐厨垃圾的减量化和资源化.

甘蔗渣和菠萝渣对黑水虻幼虫生长发育和肠道微生物的影响

本研究旨在研究甘蔗渣和菠萝渣饲喂黑水虻Hermetia illucens幼虫对其幼虫的生长性能及其肠道微生物的影响。试验分别以未发酵和自然发酵的甘蔗渣、菠萝渣为基础饲料,辅以不同比例的豆腐渣配制成不同饲料配方喂养黑水虻,测定黑水虻幼虫的生长性能及肠道微生物。结果显示,与以纯豆腐渣为基础饲料的对照(CK)相比,处理Ⅳ(80%发酵菠萝渣+20%豆腐渣)喂养黑水虻幼虫可显著提高预蛹前黑水虻幼虫平均体长、体重、生长性能及饲料利用率,降低料重比,养殖7 d后幼虫平均体长、体重、获得生物量、生长率、饲料利用率分别比CK高11.58%、46.69%、47.12%、46.75%、24.10%,料重比降低了19.18%。分别与以未发酵果渣为基础饲料的处理(Ⅰ、Ⅲ)相比,处理Ⅱ和Ⅳ提高了黑水虻预蛹前幼虫平均体长、体重、幼虫生长率和饲料利用率,降低了料重比。黑水虻幼虫肠道菌群聚类良好,处理Ⅰ~Ⅳ黑水虻幼虫肠道中,拟杆菌门的平均相对丰度显著高于CK,而处理Ⅱ~Ⅳ厚壁菌门的平均相对丰度显著低于CK,处理Ⅰ厚壁菌门的平均相对丰度差异低于CK但不显著。与CK比,处理Ⅰ~Ⅳ黑水虻幼虫肠道中,营发酵单胞菌属相对丰度(40.10%以上)显著增加,肠球菌属相对丰度显著降低,摩根氏菌属、放线菌属相对丰度降低但差异不显著,普罗威登斯菌属相对丰度增加但差异不显著。研究表明,处理Ⅳ黑水虻幼虫生长性能和饲料转化性能优于其他处理,发酵果渣处理优于非发酵处理,且不同饲料配方会引起黑水虻幼虫肠道菌群相对丰度的改变。

不同乳酸菌固态发酵对黑水虻幼虫营养价值的影响

本试验旨在探讨不同乳酸菌固态发酵对黑水虻幼虫中主要营养成分、pH、乳酸和多肽含量的影响,试验分为4组,分别为对照组(未发酵)、试验1组(植物乳杆菌组)、试验2组(粪肠球菌组)、试验3组(嗜酸乳杆菌组),每组3个平行。将黑水虻幼虫与麸皮按1:1混合,分别添加发酵用种子液,将混匀后的样品分别装入发酵袋中,放于35℃人工气候箱中发酵3 d。结果表明:与对照组相比,试验1组、2组、3组粗纤维含量均显著下降(P﹤0.05);缬氨酸含量分别增加了11.25%(P﹤0.05)、10.00%(P﹤0.05)和16.25%(P﹤0.05),脯氨酸含量分别增加了15.73%(P﹤0.05)、13.75%(P﹤0.05)和8.99%(P﹤0.05);各组之间乳酸含量差异极显著(P﹤0.01),其中试验1组乳酸含量最高,达到了8.72%;发酵后,各试验组pH显著下降(P﹤0.01),其中试验1组pH最低;发酵后3个试验组多肽含量均显著升高(P﹤0.01)。综合考虑,优先选择植物乳杆菌作为黑水虻发酵饲料发酵剂。

Fatty acids derived from oviposition systems guide female black soldier flies(Hermetia illucens)toward egg deposition sites

The black soldier fly,Hermetia illucens,comes with big promises for industrial purposes since its larvae feed polyphagously on a broad spectrum of organic substrates.However,research focusing on adult flies is scarce,which is inconsistent with their reproductive relevance within the rearing cycle.In particular,directed oviposition is a challenge in artificial systems.Currently,decomposing organic matter is commonly used as oviposition substrate,which has extensive potential for improvement in view of the lack of standardization and the risk of microbial contamination.Here,we identified three fatty acids and one fatty acid methyl ester derived from the surface of old oviposition sites and targeted to elucidate their effect on preference behavior and oviposition site selection using Y-olfactometry and prepared oviposition sites,respectively.Exposure to tetradecanoic acid attracted gravid females and stimulated oviposition most strongly,while decanoic acid demonstrated a repulsive effect.Females kept in mixed-sex populations were attracted by tetradecanoic acid,resulting in a higher egg mass found in the compound box(3.0–11.4 fold),a≥2.3 fold reduction of nonspecifically deposited eggs,and the highest total egg mass.Conversely,decanoic and dodecanoic acid caused females to lay a greater proportion of eggs nonspecifically outside both boxes.Our data suggest that fatty acids,especially tetradecanoic acid,are important cues for oviposition site selection in black soldier flies.In order to achieve a directed oviposition behavior,the role of further short-and long-chain fatty acids as attractants should be examined.

黑水虻利用有机固废开发新型饲料蛋白与碳减排研发现状和展望

黑水虻作为一种重要的资源昆虫,可以处理多种有机固废,收获虫体生物质。黑水虻虫体富含蛋白质、脂肪等营养物质,在畜禽与水产的饲料中可有效替代鱼粉和豆粕而作为新型饲料蛋白资源。黑水虻幼虫处理有机固废还可以有效减少处理过程中的碳排放,将更多的碳元素以有机物的形式固定在虫体生物质上。文章从以下几个方面进行了综述:黑水虻转化不同有机固废,及其不同废弃物搭配对黑水虻转化及黑水虻营养的影响;微生物对黑水虻转化有机固废获得黑水虻生物质、蛋白的影响;黑水虻转化有机固废的无害化;黑水虻替代鱼粉和豆粕,是极具潜力的新型“开源”饲料蛋白;黑水虻中功能性蛋白(肽)的开发利用-用于饲料蛋白“节流”;黑水虻在固碳减排方面的作用;同时对黑水虻未来研究与开发方向进行了展望,以期为黑水虻资源的开发利用提供参考。

基于鸡粪养殖的黑水虻幼虫复合滚筒筛参数研究

【目的】解决鸡粪养殖黑水虻虫沙结块分离难、黑水虻幼虫损失率高及分离设备筛分效率低的问题,探究筛分参数对黑水虻幼虫复合滚筒筛筛分效果的影响。【方法】在借助离散元软件构建滚筒筛物料颗粒筛分过程仿真模型的基础上,以外层滚筒转速、抄板高度、内层滚筒转速和滚筒倾角为试验因素,进行了4因素3水平正交试验,分析得到筛分效率和黑水虻幼虫损失率的最优筛分参数组合。【结果】当外层滚筒转速36 r·min^(-1),抄板高度20 mm,内层滚筒转速-45 r·min^(-1),滚筒倾角8°时,滚筒筛性能最优,筛分效率为95.32%,损失率为4.85%;在最优筛分参数组合条件下,样机试验结果与仿真试验结果相对误差分别为4.19%和0.55%,仿真试验与样机试验结果吻合度较好。【结论】解决了黑水虻幼虫分离设备现存问题,获得了滚筒筛分的最佳筛分参数,为黑水虻幼虫筛分设备相关研究提供参考。