Laboratory Conditions Research Articles

Development of a Tool to Manipulate Flexible Pieces in the Industry: Hardware and Software

Currently, the textile industry is a poorly automated sector, due in part to problems in the handling of deformable leather and textile parts during production operations. In this work, several problems in the handling process of leather and textile parts are addressed, introducing methods to increase the automation of the process. A pneumatic actuator designed to pick up textile or leather parts avoiding their deformation during transport has been developed. This actuator maximizes the number of gripping points to improve handling, making it more stable and efficient. Additionally, a vision system has been implemented in the part-picking task which, in conjunction with the CAD information of the part, sends the modified gripping position of the part to the robot. This allows customized handling of each textile or leather part. Finally, validation tests have been carried out on this development, both in simulations and in laboratory conditions, demonstrating its viability and direct applicability in the production line.

Linking methanotroph phenotypes to genotypes using a simple spatially resolved model ecosystem.

Connecting genes to phenotypic traits in bacteria is often challenging because of a lack of environmental context in laboratory settings. Laboratory-based model ecosystems offer a means to better account for environmental conditions compared to standard planktonic cultures, and can help link genotypes and phenotypes. Here, we present a simple, cost-effective, laboratory-based model ecosystem to study aerobic methane-oxidizing bacteria (methanotrophs) within the methane-oxygen counter gradient typically found in the natural environment of these organisms. Culturing the methanotroph Methylomonas sp. strain LW13 in this system resulted in formation of a distinct horizontal band at the intersection of the counter gradient, which we discovered was not due to increased numbers of bacteria at this location but instead to an increased amount of polysaccharides. We also discovered that different methanotrophic taxa form polysaccharide bands with distinct locations and morphologies when grown in the methane-oxygen counter gradient. By comparing transcriptomic data from LW13 growing within and surrounding this band, we identified genes upregulated within the band and validated their involvement in growth and band formation within the model ecosystem using knockout strains. Notably, deletion of these genes did not negatively affect growth using standard planktonic culturing methods. This work highlights the use of a laboratory-based model ecosystem that more closely mimics the natural environment to uncover bacterial phenotypes missing from standard laboratory conditions, and to link these phenotypes with their genetic determinants.

Both external and internal factors induce heterogeneity in senescing leaves of deciduous trees

Autumn senescence is characterised by spatial and temporal heterogeneity. We show that senescing birch (Betula spp.) leaves had lower PSII activity (probed by the FV/FM chlorophyll a fluorescence parameter) in late autumn than in early autumn. We confirmed that PSII repair slows down with decreasing temperature, while rates of photodamage and recovery, measured under laboratory conditions at 20°C, were similar in these leaves. We propose that low temperatures during late autumn hinder repair and lead to accumulation of non-functional PSII units in senescing leaves. Fluorescence imaging of birch revealed that chlorophyll preferentially disappeared from inter-veinal leaf areas. These areas showed no recovery capacity and low non-photochemical quenching while green veinal areas of senescing leaves resembled green leaves. However, green and yellow leaf areas showed similar values of photochemical quenching. Analyses of thylakoids isolated from maple (Acer platanoides) leaves showed that red, senescing leaves contained high amounts of carotenoids and α-tocopherol, and our calculations suggest that α-tocopherol was synthesised during autumn. Thylakoids isolated from red maple leaves produced little singlet oxygen, probably due to the high antioxidant content. However, the rate of PSII photodamage did not decrease. The data show that the heterogeneity of senescing leaves must be taken into account to fully understand autumn senescence.

Natural Diversity of Cuticular Pheromones in a Local Population of Drosophila after Laboratory Acclimation

Experimental studies of insects are often based on strains raised for many generations in constant laboratory conditions. However, laboratory acclimation could reduce species diversity reflecting adaptation to varied natural niches. Hydrocarbons covering the insect cuticle (cuticular hydrocarbons; CHCs) are reliable adaptation markers. They are involved in dehydration reduction and protection against harmful factors. CHCs can also be involved in chemical communication principally related to reproduction. However, the diversity of CHC profiles in nature and their evolution in the laboratory have rarely been investigated. Here, we sampled CHC natural diversity in Drosophila melanogaster flies from a particular location in a temperate region. We also measured cis-Vaccenyl acetate, a male-specific volatile pheromone. After trapping flies using varied fruit baits, we set up 21 D. melanogaster lines and analysed their pheromones at capture and after 1 to 40 generations in the laboratory. Under laboratory conditions, the broad initial pheromonal diversity found in male and female flies rapidly changed and became more limited. In some females, we detected CHCs only reported in tropical populations: the presence of flies with a novel CHC profile may reflect the rapid adaptation of this cosmopolitan species to global warming in a temperate area.

Error Analysis of Common Power Meter Installation Faults on Three-Phase Networks

The article is concerned with the operation of electric power quality meters and analyzers when incorrectly installed on a three-phase electrical network. An analytical study of the meter’s errors under the conditions of faulty installation was carried out. All possible types of installation errors are considered according to the proposed classification, as well as possible combinations of a pair of installation faults simultaneously. Classification of installation faults is also proposed. Matrix expressions are derived that allow modeling of any type of installation faults to quantify power and symmetry measurement errors. The proposed method allows to obtain quantitative signs that can identify a specific installation fault. The results of this study can help the development of an algorithm for the automatic detection of installation faults and their correction. The analytical results were confirmed by simulation studies on a three-phase network model in the MATLAB/SIMULINK environment. Experimental results, obtained from a commercial power quality analyzer operated under controlled laboratory conditions, are also reported.

Evolution of phenotypic variance provides insights into the genetic basis of adaptation.

Most traits are polygenic, and the contributing loci can be identified by GWAS. The genetic basis of adaptation is, however, difficult to characterize. Here, we propose to study the genetic basis of trait evolution by monitoring the evolution of their phenotypic variance during adaptation to a new environment in well-defined laboratory conditions. Extensive computer simulations show that the evolution of phenotypic variance in a replicated experimental evolution setting can distinguish between oligogenic and polygenic adaptive architectures. We compared gene expression variance in male Drosophila simulans before and after 100 generations of adaptation to a novel hot environment. The variance change in gene expression was indistinguishable for genes with and without a significant change in mean expression after 100 generations of evolution. We suggest that the majority of adaptive gene expression evolution can be explained by a polygenic architecture. We propose that tracking the evolution of phenotypic variance across generations can provide an approach to characterize the adaptive architecture.

Antioxidant Systematic Alteration Was Responsible for Injuries Inflicted on the Marine Blue Mussel Mytilus edulis Following Strontium Exposure

The ionic properties of strontium (Sr), a significant artificial radionuclide in the marine environment, were estimated using a stable nuclide-substituting experimental system under controlled laboratory conditions. The bio-accumulation of Sr and its impacts, as well as any possible hidden mechanisms, were evaluated based on the physiological alterations of the sentinel blue mussel Mytilus edulis. The mussels were exposed to a series of stress-inducing concentrations, with the highest solubility being 0.2 g/L. No acute lethality was observed during the experiment, but sublethal damage was evident. Sr accumulated in a tissue-specific way, and hemolymph was the target, with the highest accumulating concentration being 64.46 µg/g wet weight (ww). At the molecular level, increases in the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and changes in ROS components (H2O2, O2−, and -OH) and antioxidant system activity indicated that the redox equilibrium state in hemocytes was disturbed. Furthermore, the rise in the hemocyte micronucleus (MN) rate (4‰ in the high-concentration group) implied DNA damage. At the cellular level, the structures of hemocytes were damaged, especially with respect to lysosomes, which play a crucial role in phagocytosis. Lysosomal membrane stability (LMS) was also affected, and both acid phosphatase (ACP) and alkaline phosphatase (AKP) activities were reduced, resulting in a significant decline in phagocytosis. The hemolymph population structure at the organ level was disturbed, with large changes in hemocyte number and mortality rate, along with changes in component ratios. These toxic effects were evaluated by employing the adverse outcome pathway (AOP) framework. The results suggested that the disruption of intracellular redox homeostasis is a possible explanation for Sr-induced toxicity in M. edulis.

Effects of Disinfectants on Bacterium Paenibacillus larvae in Laboratory Conditions

American foulbrood is an infectious disease of the honeybee brood that causes multiple types of damage to beekeeping. The causative agent of the disease is the bacterium Paenibacillus larvae, which forms resistant infective spores and is viable for decades. After the eradication measures have been implemented, in cases of clinically visible disease, it is necessary to conduct effective final disinfections of equipment and tools. This study aimed to determine the effect of ten commercially available and commonly used disinfectants on certified strains of P. larvae under laboratory conditions, as well as to compare the obtained results among individual genotypes of P. larvae. Selected products were tested by determining the zone of inhibition using an agar diffusion test, a suspension test for viable bacteria, a surface disinfectant test, and a sporicidal effect in the suspension test. Incidin OxyFoam S and Sekusept Aktiv are both effective against all examined genotypes of P. larvae. Despadac and Despadac Secure have a bactericidal effect, but their sporocidal effect is not as satisfactory as that of Genox. Genoll does not exhibit a sporicidal effect, and Ecocide S at 1%, Bee protect H forte, and Bee protect F did not exhibit a satisfactory sporocidal effect. Additionally, EM® PROBIOTIC FOR BEES did not exhibit any bactericidal effect. The effective application of control measures and proper application of final disinfection can reduce the reoccurrence of visible clinical signs of disease, whereas methods of early diagnosis can significantly reduce the incidence of the disease.

Measurement and Analysis of Last-Mile Parcel Delivery Truck Vibration Levels in Korea

South Korea has one of the largest e-commerce markets in the world. The last-mile delivery segment of e-commerce often causes critical damage to products in protective packages. Despite the rapid growth of the e-commerce market in Korea, the last-mile distribution environment has not yet been thoroughly investigated. The main aim of this study was to provide an understanding of the vibration levels that were measured from various parcel delivery routes within Seoul, Korea, using common types of parcel delivery trucks. Vibration levels of ten delivery trucks were measured and analyzed in terms of power spectral densities (PSDs) and presented as PSD spectra. The last-mile delivery vehicle vibration levels in Korea were found to be consistently lower (in the 1 to 200 Hz frequency range) than those recommended by international standards and lower than the vibration levels of parcel delivery vehicles in the U.S. and Hungary. The results also revealed that the highest intensity peak of the PSD spectrum for Korea was located in the lower frequency range (1.5 to 2 Hz) compared to the ISTA 3A pickup and delivery test profile (3 to 4 Hz) and the test profile recommended for Hungary (13 to 16 Hz). A smoothed composite spectrum was also provided to support Korean packaging engineers in optimizing their packages by simulating proper last-mile truck delivery vibration levels in lab conditions.

To attract a moth: Wind tunnel and field testing of plant odor and light stimuli and their combination for Ostrinia nubilalis

AbstractThe European corn borer, Ostrinia nubilalis (Hubner), relies on multimodal sensory information to find food, mates, mating and ovipositional grounds. Successful phytosanitary monitoring demands for the bait for the field traps to obtain the most reliable representation of pest abundance. Attraction to light and blend of key components of host plant odor, was tested both in the laboratory and field conditions. Ultraviolet light, which was the most effective in the wind tunnel experiments, was further tested in the field alone and in combination with bisexual lure. Bisexual lure, being attractive in the lab, as well as in the field, did not improve responses to ultraviolet in both experimental designs. All three baits attracted significantly more females than males in the field. Wind tunnel experiments revealed that ultraviolet elicited the shortest response latencies either alone or paired with the odor bait. The lack of synergistic effect between attractive light and odor stimuli is an important issue for pest monitoring. The possible reasons for the observed lack of synergy are the hierarchy of behavioral responses to different stimuli or the intensities of both stimuli are critically important for attractivity of combined stimulus and differ from separately presented ones.

Repellent Effects of Insecticide Formulations on Sweet Potato Whitefly1 under Laboratory Conditions

Repellent Effects of Insecticide Formulations on Sweet Potato Whitefly1 under Laboratory Conditions

A Novel Interaction of Nesidiocoris tenuis (Hemiptera: Miridae) as a Biological Control Agent of Bactericera cockerelli (Hemiptera: Triozidae) in Potato

Nesidiocoris tenuis (Hemiptera: Miridae) is a generalist predator commonly used to control the whitefly Bemisia tabaci in Europe. This mirid has been found and established in South Texas, where it was initially observed feeding on nymphs of the psyllid Bactericera cockerelli (Hemiptera: Triozidae) in open tomato fields. B. cockerelli is the vector of the fastidious bacterium “Candidatus Liberibacter solanacearum” that causes diseases in several solanaceous crops, including zebra chip (ZC) disease in potatoes. There is a need to better understand how this predator impacts the control of important crop pests, such as potato psyllids. We assessed the interactions between N. tenuis and B. cockerelli in three different environmental settings. First, we estimated the numeric response of N. tenuis preying on B. cockerelli under laboratory and greenhouse conditions. Second, we evaluated the predator–prey interaction under controlled field cage conditions. Then, we exposed N. tenuis under controlled field release conditions to the natural occurrence of B. cockerelli. Finally, we assessed the compatibility between the use of N. tenuis as a biological control agent in a field study and its impact on ZC disease incidence, severity in potato tubers, and potato yield. Laboratory and greenhouse experiments resulted in diverse types of functional model responses, including exponential and linear mathematical models. Our findings revealed a significant predation effect exerted by N. tenuis, resulting in a reduction of more than fourfold in the number of B. cockerelli nymphs per cage. Specifically, the nymphal population decreased from 21 ± 3.2 in the absence of N. tenuis to 5 ± 1.6 when N. tenuis was present. Furthermore, the combination of N. tenuis with a reduced insecticide program increased potato yields, but only reduced ZC tuber incidence in one of two potato cultivars evaluated, and in one season. Findings from these studies indicate that N. tenuis could be effective as a biological control agent for B. cockerelli in potato production in South Texas. This is the first report of N. tenuis preying on immature stages of any psyllid species.

Physical training in the prevention of sea sickness

Abstract Disorders related to labyrinth irritation (kinetosis) constitute a significant problem in sea travel, especially in sea service. A team of military researchers conducted research on a very large group (over 200 people) regarding the possibility of preventing seasickness through physical training. An original set of exercises was developed and performed by the study group. Then, the sensitivity of the test group and the control group to rocking was checked in laboratory and real conditions (sea cruise). The method has been shown to be over 50% effective in preventing and alleviating the symptoms of seasickness. The use of selected physical exercises may be an effective training against the risk of kinetosis.

Centrifugal Pump Fault Detection with Convolutional Neural Network Transfer Learning

The centrifugal pump is the workhorse of many industrial and domestic applications, such as water supply, wastewater treatment and heating. While modern pumps are reliable, their unexpected failures may jeopardise safety or lead to significant financial losses. Consequently, there is a strong demand for early fault diagnosis, detection and predictive monitoring systems. Most prior work on machine learning-based centrifugal pump fault detection is based on either synthetic data, simulations or data from test rigs in controlled laboratory conditions. In this research, we attempted to detect centrifugal pump faults using data collected from real operational pumps deployed in various places in collaboration with a specialist pump engineering company. The detection was done by the binary classification of visual features of DQ/Concordia patterns with residual networks. Besides using a real dataset, this study employed transfer learning from the image detection domain to systematically solve a real-life problem in the engineering domain. By feeding DQ image data into a popular and high-performance residual network (e.g., ResNet-34), the proposed approach achieved up to 85.51% classification accuracy.

Improving the Decay Resistance of Wood through the Fixation of Different Nanoparticles Using Silica Aerogel

Nowadays, the protection of wood is becoming more important with the increasing demand for durable wood, in addition to its limited accessibility. One possible way to increase the durability is the use of nanoparticles, which can be effective even with a low intake of active ingredients. However, avoiding their leaching is a challenge. A possible solution to leaching is the use of silica aerogel as a fixative. This study investigated the use of mesoporous silica aerogel against the leaching of different nanoparticles under laboratory conditions. Tests were performed involving beech (Fagus sylvatica) and Scots pine (Pinus sylvestris) sapwood, using Trametes versicolor as a white rot and Coniophora puteana as a brown rot fungus. The results show that the subsequent treatment of the wood with mesoporous silica aerogel effectively fixed the nanoparticles in wood. The durability of the samples without aerogel significantly decreased as a result of leaching, whereas the resistance of the samples treated with aerogel decreased only slightly. However, the silica aerogel modification itself caused the leaching of silver nanoparticles, which is a limitation in the use of this method for the fixation of nanoparticles.

Pesticidal activity of extra cellular metabolites extracted from the green muscardian fungi Metarhizium anisopliae

AbstractThe present study was undertaken to screen the pesticidal activity of extra cellular metabolites derived from entomopathogenic fungus Metarhizium anisopliae against Spodoptera litura and Aphis crassivora an important aphid pest under laboratory and pot culture condition. Fungal strain used in the study was isolated from the soil by serial dilution technique. Isolated fungal strain was mass multiplied in a liquid medium sabouraud maltose yeast extract broth under optimum condition (28°C). Culture filtrate and the collected culture derived from the medium was used for the source of metabolites. The culture filtrate was extracted with ethyl acetate, acetone and the concentrated extract was screened for pesticidal activity against Spodoptera litura and Aphis crassivora adopting leaf disc and pot culture assay respectively. Extracted metabolites showed pesticidal activity against both insect pests. However, notable effect was recorded in ethyl acetate derived metabolites. The ethyl acetate extract treatment recorded 91.2% mortality at a concentration of 100 μg against Spodoptera litura and 100% mortality at a concentration of 100 μg against Aphis crassivora. Phytotoxicity was determined by measuring the germination index (GI) of groundnut seeds by exposing it to the crude metabolites extracted in ethyl acetate and acetone. The results showed that the germination index was high on ethyl acetate extract which was recorded to be 98.0% and germination index of acetone extract was found to be 90.0%. Production of insecticidal metabolites from M. anisopliae under laboratory condition proposed the possible utilization of metabolites as an effective, safe pesticidal agent against economic important insect pests. No impact on the seedling emergence revealed non phytotoxic effect of the metabolites.

Laboratory evaluation of the contact irritancy of a clothianidin solo formulation vs. clothianidin-deltamethrin mixture formulations for indoor residual spraying against pyrethroid-resistant Anopheles gambiae sensu lato

BackgroundClothianidin-based indoor residual spraying (IRS) formulations have become available for malaria control as either solo formulations of clothianidin or a mixture of clothianidin with the pyrethroid deltamethrin. While both formulations have been successfully used for malaria control, studies investigating the effect of the pyrethroid in IRS mixtures may help improve our understanding for development of future IRS products. It has been speculated that the irritant effect of the pyrethroid in the mixture formulation may result in shorter mosquito contact times with the treated walls potentially leading to a lower impact.MethodsWe compared contact irritancy expressed as the number of mosquito take-offs from cement surfaces treated with an IRS formulation containing clothianidin alone (SumiShield® 50WG) to clothianidin-deltamethrin mixture IRS formulations against pyrethroid-resistant Anopheles gambiae sensu lato under controlled laboratory conditions using a modified version of the World Health Organisation cone bioassay. To control for the pyrethroid, comparison was made with a deltamethrin-only formulation. Both commercial and generic non-commercial mixture formulations of clothianidin and deltamethrin were tested.ResultsThe clothianidin solo formulation did not show significant contact irritancy relative to the untreated control (3.5 take-offs vs. 3.1 take-offs, p = 0.614) while all deltamethrin-containing IRS induced significant irritant effects. The number of take-offs compared to the clothianidin solo formulation (3.5) was significantly higher with the commercial clothianidin-deltamethrin mixture (6.1, p = 0.001), generic clothianidin-deltamethrin mixture (7.0, p < 0.001), and deltamethrin-only (8.2, p < 0.001) formulations. The commercial clothianidin-deltamethrin mixture induced similar contact irritancy as the generic clothianidin-deltamethrin mixture (6.1 take-offs vs. 7.0 take-offs, p = 0.263) and deltamethrin-only IRS (6.1 take-offs vs. 8.2, p = 0.071), showing that the irritant effect in the mixture was attributable to its deltamethrin component.ConclusionsThis study provides evidence that the enhanced contact irritancy of the pyrethroid in clothianidin-deltamethrin IRS mixtures can shorten mosquito contact times with treated walls compared to the clothianidin solo formulation. Further trials are needed to directly compare the efficacy of these formulation types under field conditions and establish the impact of this enhanced contact irritancy on the performance of IRS mixture formulations containing pyrethroids.Graphical

Stage-specific insecticide susceptibility and life-table analysis of the dengue vector mosquitoes &lt;em&gt;Aedes aegypti&lt;/em&gt; and &lt;em&gt;Ae. albopictus&lt;/em&gt;

Vector resistance to insecticides is a significant challenge in the control of mosquito-borne diseases such as dengue. Analysis of the growth rate and survivorship of the immature stages of larvae has been important in formulating effective vector control strategies. The present study aimed to assess insecticide resistance in both larvae and adults of Aedes aegypti and Ae. albopictus, and the life tables of their immature stages.Mosquito eggs collected from Kurunegala and Colombo districts of Sri Lanka from January to March 2023 were reared under laboratory conditions. Larval bioassays were carried out with temephos (0.0125 ppm, 0.0625ppm and 0.125ppm) and, the adult bioassays were with pyrethroids (0.03% deltamethrin, 0.05% and 0.08% lambdacyhalothrin, 0.04% permethrin) and malathion (1%and 5%). Biochemical assays were used to evaluate the activity of insecticide-detoxifying enzymes and the insensitivity of the organophosphate target site acetylcholinesterase. Survivorship of immature stages under laboratory conditions and semi-field conditions i.e., bamboo stumps, tyres and clay pots, were studied using Kaplan-Meier survival analysis.Larvae and adults of both species from Kurunegala were susceptible to all the insecticides tested, whereas Colombo populations were resistant. Acetylcholinesterases were largely sensitive in all vector populations. Higher activities of esterases, glutathione s-transferases and monooxygenases were found in Colombo populations. Results indicated that Ae. aegypti larvae were more resistant to insecticides than Ae. albopictus larvae. Also, the mechanisms of insecticide resistance were well developed in adults than in larvae.Aedes aegypti larval development time (5 days) was significantly shorter than that of Ae. albopictus (9 days) under laboratory conditions. Survival probabilities of them were 76-80%. Egg hatching to adult emergence period was 8 days for Ae. aegypti and 13 days for Ae. albopictus. This period, under semifield conditions were; bamboo stumps 7-7.2 days, tyres 10-11.3 days, and clay pots 13.8-14 days with survival rates varied from 28.8 to 63% for both species. This study highlights stage specific response of dengue vectors to insecticides and survivorship of their immature stages in different habitats. This knowledge can be effectively used in future dengue vector control programmes.

Sitting knee-flexion angle does not influence endothelial-dependent vasodilation in laboratory or free-living conditions.

Single bouts of prolonged bent-legged sitting attenuate popliteal endothelial-dependent vasodilation (as assessed via flow-mediated dilation [FMD]), which is partially attributed to arterial 'kinking'. However, the impact of knee-flexion angle on sitting-induced popliteal FMD is unknown. The objective of this study was to perform separate laboratory and free-living studies to test the hypotheses that: (1) popliteal FMD impairments would be graded between knee flexions at 90° (bent-legged sitting) > 45° > 0° (straight-legged sitting) following a 3-hour bout of sitting; and (2) more habitual time spent bent-legged sitting (< 45°) would be associated with lower FMD. The laboratory study included eight young, healthy adults (24 ± 2 years; four women) who underwent two sitting bouts over 2 days with one leg positioned at a knee-flexion angle of 0° or 90° and the opposite leg at 45° knee flexion. Popliteal FMD was assessed at pre- and postsitting timepoints. Sitting-induced reductions in FMD were similar between all knee-flexion angles (all, p > 0.674). The free-living study included 35 young, healthy adults (23 ± 3 years; 16 women) who wore three activPAL monitors (torso, thigh, shin) to determine detailed sedentary postures. Time spent sedentary (624 ± 127 min/day), straight-legged sitting (112 ± 98 min/day), and bent-legged sitting (442 ± 106 min/day) were not related to relative FMD (5.3 ± 1.8%; all, p > 0.240). These findings suggest that knee-flexion angle-mediated arterial 'kinking' during sitting is not a major contributor toward sitting-induced popliteal endothelial-dependent vasodilatory dysfunction.

Anopheles aquatic development kinetic and adults’ longevity through different seasons in laboratory and semi-field conditions in Burkina Faso

AbstractBackgroundAnopheles mosquitoes are ectothermic and involved in numerous pathogen transmissions. Their life history traits are influenced by several environmental factors such as temperature, relative humidity and photoperiodicity. Despite extensive investigations of these environmental conditions on vector population ecology, their impact on the different life stages of Anopheles at different seasons in the year remains poorly explored. This study reports the potential impact of these abiotic factors on the immature and adult stages of Anopheles gambiae sensu lato during different seasons.MethodsEnvironmental conditions were simulated in the laboratory using incubators to mimic the environmental conditions of two important periods of the year in Burkina Faso: the peak of rainy season (August) and the onset of dry season (December). Eggs from wild An. coluzzii and An. gambiae s.l. were reared separately under each environmental condition. For Anopheles coluzzii or An. gambiae s.l., eggs were equally divided into two groups assigned to the two experimental conditions. Four replicates were carried out for this experiment. Then, egg hatching rate, pupation rate, larval development time, larva-to-pupae development time, adult emergence dynamics and longevity of Anopheles were evaluated. Also, pupae-to-adult development time from wild L3 and L4 Anopheles larvae was estimated under semi-field conditions in December.ResultsA better egg hatching rate was recorded overall with conditions mimicking the onset of the dry season compared to the peak of the rainy season. Larval development time and longevity of An. gambiae s.l. female were significantly longer at the onset of the dry season compared than at the peak of the rainy season. Adult emergence was spread over 48 and 96 h at the peak of the rainy season and onset of dry season conditions respectively. This 96h duration in the controlled conditions of December was also observed in the semi-field conditions in December.ConclusionsThe impact of temperature and relative humidity on immature stages and longevity of An. gambiae s.l. adult females differed under both conditions. These findings contribute to a better understanding of vector population dynamics throughout different seasons of the year and may facilitate tailoring of control strategies.Graphical