Dataset Information

Contrasting Manual and Automated Assessment of Thermal Stress Responses and Larval Body Size in Black Soldier Flies and Houseflies.

ABSTRACT: Within ecophysiological and genetic studies on insects, morphological and physiological traits are commonly assessed and phenotypes are typically obtained from manual measurements on numerous individuals. Manual observations are, however, time consuming, can introduce observer bias and are prone to human error. Here, we contrast results obtained from manual assessment of larval size and thermal tolerance traits in black soldier flies (Hermetia illucens) and houseflies (Musca domestica) that have been acclimated under three different temperature regimes with those obtained automatically using an image analysis software (Noldus EthoVision XT). We found that (i) larval size estimates of both species, obtained by manual weighing or by using the software, were highly correlated, (ii) measures of heat and cold tolerance using manual and automated approaches provided qualitatively similar results, and (iii) by using the software we obtained quantifiable information on stress responses and acclimation effects of potentially higher ecological relevance than the endpoint traits that are typically assessed when manual assessments are used. Based on these findings, we argue that automated assessment of insect stress responses and largescale phenotyping of morphological traits such as size will provide new opportunities within many disciplines where accurate and largescale phenotyping of insects is required.

SUBMITTER: Laursen SF

PROVIDER: S-EPMC8146041 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The use of the black soldier fly has been demonstrated to be effective in the treatment of swine manure. Since the outbreaks of ASFV, prevention procedures, including manure disinfection, have changed dramatically. Glutaraldehyde (GA) and potassium peroxymonosulfate (PPMS) have been shown to be effective in the prevention of this pathogen and are thus widely used in the disinfection of swine manures, etc. However, research on the effects of disinfectants in manures on the growth of BSFL and gut microbiota is scarce. The goal of this study was to determine the effects of GA and PPMS on BSFL growth, manure reduction, and gut microbiota. In triplicate, 100 larvae were inoculated in 100 g of each type of manure compound (manure containing 1% GA treatment (GT1), manure containing 0.5% GA treatment (GT2), manure containing 1% PPMS treatment (PT1), manure containing 0.5% PPMS treatment (PT2), and manure without disinfectant (control)). After calculating the larval weight and waste reduction, the larval gut was extracted and used to determine the microbial composition. According to the results, the dry weights of the larvae fed PT1-2 (PT1: 86.7 ± 4.2 mg and PT2: 85.3 ± 1.3 mg) were significantly higher than those of the larvae fed GT1-2 (GT1: 72.5 ± 2.1 mg and GT2: 70 ± 2.8 mg) and the control (64.2 ± 5.8 mg). There was a 2.8-4.03% higher waste reduction in PT1-2 than in the control, and the waste reduction in GT1-2 was 7.17-7.87% lower than that in the control. In a gut microbiota analysis, two new genera (Fluviicola and Fusobacterium) were discovered in PT1-2 when compared to GT1-2 and the control. Furthermore, the disinfectants did not reduce the diversity of the microbial community; rather, Shannon indices revealed that the diversities of GT1-2 (GT1: 1.924 ± 0.015; GT2: 1.944 ± 0.016) and PT1 (1.861 ± 0.016) were higher than those of the control (1.738 ± 0.015). Finally, it was found that both disinfectants in swine manures at concentrations of 1% and 0.5% may be beneficial to the complexity and cooperation of BSFL gut microbiota, according to an analysis of microbial interactions.

Project description:Black soldier fly (BSF), Hermetia illucens (L.) (Diptera: Stratiomyidae), is a promising bio-agent to transform organic wastes into valuable insect biomass, and the intestinal microbes play an essential role in this process. Here, we report that Citrobacter amalonaticus, a Gram-negative gut commensal bacterium of BSF larvae, can colonize the whole intestines of the larva and significantly promote the larval growth and development. The bacterial association with the larva had a marked impact on the larval transcriptome and modulated the expression of genes involved in dozens of biological pathways including host macro-nutrient metabolism and immune response. We investigated the underlying mechanisms driving the interaction and found that C. amalonaticus association can directly promote the expression of two gene families related to intestinal protein metabolism: Hitryp serine protease trypsin family and Himtp metallopeptidase family. To determine the gene function, we developed a symbiont-mediated double-strand RNA interference approach and successfully achieved gene knockdown in larval midgut in situ. Knockdown of the two gene families and protease inhibition in larval intestines attenuated the promoting effects on larval growth significantly. The results indicate that the gut symbiont promotes BSF larval growth partly via modulating the expression of the genes involved in intestinal protein metabolism. Taken together, this study establishes a novel genetic tool to study the insect functional genomics and the host-symbiont interaction and sheds light on the important roles of intestinal protein metabolism on the interaction. IMPORTANCE Black solider fly larvae and the gut microbiota can recycle nutrients from various organic wastes into valuable insect biomass. We found that Citrobacter amalonaticus, a gut commensal bacterium of the insect, exerts beneficial effects on larval growth and development and that the expression of many metabolic larval genes was significantly impacted by the symbiont. To identify the larval genes involved in the host-symbiont interaction, we engineered the symbiont to produce double-strand RNA and enabled the strain to silence host genes in the larval gut environment where the interaction takes place. With this approach, we confirmed that two intestinal protease families are involved in the interaction and provided further evidence that intestinal protein metabolism plays a role in the interaction. This work expands the genetic toolkits available to study the insect functional genomics and host-symbiont interaction and provide the prospective for the future application of gut microbiota on the large-scale bioconversion.

Project description:Black soldier fly (Hermetia illucens) larvae can convert biowaste and by-products into body mass high in protein (~40% dry matter, DM) and lipid (~30% DM). However, the type of rearing substrate also affects the larval body composition and thus its nutritional value. Hitherto, it remains unclear how and to what extent the larval body composition can be altered by the substrate. This study was therefore performed to examine the possibilities of modifying larval body composition using different rearing substrates. To investigate this, 5-days old larvae were reared for seven days on different locally available waste and by-products: brewer's spent grain, mitigation mussels (Mytilus edulis), rapeseed cake, and shrimp waste meal (Pandalus borealis). Larval composition and performance were compared to larvae reared on a commercial chicken feed as well as a mixed feed (mixture of chicken feed and by-products, with a similar macronutrient composition to chicken feed). Larval body weight was recorded daily to determine growth over time whereas larvae and substrates were sampled at the start and end of the trial and analysed for their nutritional composition. The type of rearing substrate affected both larval body composition and growth performance. There was a clear relation between the nutritional composition of the substrate and larvae for certain fatty acids. Larvae reared on marine-based waste substrates contained a higher share of omega-3 fatty acids than larvae reared on the other substrates, indicating an accumulation of omega-3 fatty acids from the substrate. There was a strong positive linear correlation between the ash content in the substrate and larvae whereas larval lipid, protein, amino acid, and chitin content seemed more affected by larval development. Overall, this study showed that the rearing substrate affects larval composition and development, and that larval composition of certain nutrients can be tailored depending on further food and feed applications.

Dataset Information

Contrasting Manual and Automated Assessment of Thermal Stress Responses and Larval Body Size in Black Soldier Flies and Houseflies.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets