Solitary Phase Research Articles

Size-dependent responses of colony-founding bumblebee (Bombus impatiens) queens to exposure to pesticide residues in soil during hibernation

Bumblebees and other key pollinators are experiencing global declines, a phenomenon driven by multiple environmental stressors, including pesticide exposure. While bumblebee queens spend most of their life hibernating underground, no study to date has examined how exposure to pesticide-contaminated soils might affect bumblebee queens during this solitary phase of their lifecycle. We exposed Bombus impatiens queens (n = 303) to soil treated with field-realistic concentrations of two diamide insecticides (chlorantraniliprole and cyantraniliprole) and two fungicides (boscalid and difenoconazole), alone or combined, during a 30-week hibernation period. We found that exposure to boscalid residues in soil doubled the likelihood of queens surviving through the colony initiation period (after successful hibernation) and laying eggs. Our data also revealed complex interactions between pesticide exposure and queen body mass on aspects of colony founding. Among others, exposure to cyantraniliprole led to lethal and sublethal post-hibernation effects that were dependent on queen size, with larger queens showing higher mortality rates, delayed emergence of their first brood, and producing smaller workers. Our results show that effects of pesticide exposure depend on intrinsic traits of bumblebee queen physiology and challenge our understanding of how bees respond to pesticides under environmentally realistic exposure scenarios.

A neural m6A pathway regulates behavioral aggregation in migratory locusts.

RNA N6-methyladenosine (m6A), as the most abundant modification of messenger RNA, can modulate insect behaviors, but its specific roles in aggregation behaviors remain unexplored. Here, we conducted a comprehensive molecular and physiological characterization of the individual components of the methyltransferase and demethylase in the migratory locust Locusta migratoria. Our results demonstrated that METTL3, METTL14 and ALKBH5 were dominantly expressed in the brain and exhibited remarkable responses to crowding or isolation. The individual knockdown of methyltransferases (i.e., METTL3 and METTL14) promoted locust movement and conspecific attraction, whereas ALKBH5 knockdown induced a behavioral shift toward the solitary phase. Furthermore, global transcriptome profiles revealed that m6A modification could regulate the orchestration of gene expression to fine tune the behavioral aggregation of locusts. In summary, our in vivo characterization of the m6A functions in migratory locusts clearly demonstrated the crucial roles of the m6A pathway in effectively modulating aggregation behaviors.

Microstructure, bonding characteristics, far-infrared spectra and microwave dielectric properties of co-substituted Ce2[(Zr1-x(Zn1/3Sb2/3)x]3(MoO4)9 ceramics

In this contribution, Ce2[(Zr1-x(Zn1/3Sb2/3)x]3(MoO4)9 (CZ1−x(ZS)x) (0 ≤ x ≤ 0.1) ceramics were fabricated using the solid-state reaction method, and the phase composition of the synthesized ceramics was analyzed via XRD and Rietveld refinement. The outcomes revealed that the ceramics, characterized by different x values, constituted a solitary phase with an R-3C space group, and the cell volume demonstrated a decrease with an increase in x value. The examination of the ceramics microwave dielectric characteristics using P–V−L theory reveals that the fi(Ce–O(6)) bond was found to be related to εr, while Q × f was influenced by the average grain size and Uave.(Mo–O), and Eave.(Mo–O) and αave.(Mo–O) were related to the τf value. The optimal properties were achieved at 750 °C (x = 0.02), resulting in εr = 10.08, Q × f = 100,954 GHz, τf = −12.46 ppm/°C. The infrared reflection spectrum analysis revealed that the primary polarization contribution was due to the dielectric response of intrinsic phonons. Additionally, the effects of three different complex ions (Zn1/2Sb2/3)4+, (Zn1/2Ta2/3)4+, and (Zn1/2Nb2/3)4+ doping on the properties of Ce2Zr3(MoO4)9 ceramics were investigated using SEM, packing fraction, and chemical bond analysis. The results showed that (Zn1/2Sb2/3)4+ doping was effective in improving the grain size and apparent density of Ce2Zr3(MoO4)9 ceramics, and the high packing fraction and U(Mo–O) were found to be the primary intrinsic factors for the optimal properties.

Zn-doped NiO nanocomposites for efficient solar light-assisted wastewater treatment and its profound for low phytotoxic and antibacterial applications

The present research aims to eradicate methylene blue toxins (test effluent) in aquatic environments using photocatalytic Zn-doped NiO nanoparticles. Ultrasonic-assisted co-precipitation process was adopted to synthesize Zn-doped NiO nanoparticles. The prepared samples were characterized by XRD, SEM, in vitro antibacterial, phytotoxicity, and photocatalytic analysis. XRD patterns exhibited a solitary phase of Fm3m space-group-cubic-structured Zn-doped NiO crystallites with a preferred orientation along the (200) plane. SEM analysis explored the formation of nanorods with hexagonal ends. Zn-doped NiO is capable of rendering significant antibacterial efficacy against Staphylococcus aureus (MTCC 25923) and Escherichia coli (MTCC 25922) bacterial strains. Zn-doped NiO nanocomposites are appropriate for decomposing methylene blue (MB) contaminants in 120 minutes under direct sunlight irradiation. Hydroponically grown Vigna radiata seedlings and Mentha piperita L plants in dye-deprived water show minimal phytotoxicity and enhanced physiological aspects of plants. The outcome of the current research encouraged bringing new ideas for further utilization of textile MB effluent after photocatalytic treatment to non-domestic applications, such as irrigating roadside plants, public parks, and gardens.

4-Vinylanisole promotes conspecific interaction and acquisition of gregarious behavior in the migratory locust

Chemical signals from conspecifics are essential in insect group formation and maintenance. Migratory locusts use the aggregation pheromone 4-vinylanisole (4VA), specifically released by gregarious locusts, to attract and recruit conspecific individuals, leading to the formation of large-scale swarms. However, how 4VA contributes to the transition from solitary phase to gregarious phase remains unclear. We investigated the occurrence of locust behavioral phase changes in the presence and absence of 4VA perception. The findings indicated that solitary locusts require crowding for 48 and 72 h to adopt partial and analogous gregarious behavior. However, exposure to increased concentrations of 4VA enabled solitary locusts to display behavioral changes within 24 h of crowding. Crowded solitary locusts with RNAi knockdown of Or35, the specific olfactory receptor for 4VA, failed to exhibit gregarious behaviors. Conversely, the knockdown of Or35 in gregarious locusts resulted in the appearance of solitary behavior. Additionally, a multi-individual behavioral assay system was developed to evaluate the interactions among locust individuals, and four behavioral parameters representing the inclination and conduct of social interactions were positively correlated with the process of crowding. Our data indicated that exposure to 4VA accelerated the behavioral transition from solitary phase to gregarious phase by enhancing the propensity toward proximity and body contact among conspecific individuals. These results highlight the crucial roles of 4VA in the behavioral phase transition of locusts. Furthermore, this study offers valuable insights into the mechanisms of behavioral plasticity that promote the formation of locust swarms and suggests the potential for 4VA application in locust control.

Behaviour in a novel environment provides clues to the success of an invasive species

AbstractBehavioural traits play an important role in invasion success, yet little is known about how species behave when they arrive in a new environment. In this study we examined the behaviour of the invasive shrimp Palaemon macrodactylus after entering in a novel place with a single refuge during a 24 h solitary phase, and after the introduction of a conspecific or heterospecific (the native goby Gobiosoma parri), in the next 24 h (competition phase), comparing their responses as residents and as intruders. Time spent swimming, using the shelter and the frequency of interactions (withdrawing touches) were quantified. Shrimps entering to a new empty environment, swam most of the time in the first hours, while the use of shelter increased steadily. The use of shelter in shrimps was affected by sex and residency status. Females won the shelter to males, while residents won the shelter to intruders. In the interspecific competition, refuge was always won by gobies and shrimps showed no resistance. Obtaining shelter was not generated through aggressive behaviours, but rather a hierarchy established through some other type of interactions. We propose that both prolonged swimming, which could indicate exploratory behaviour, and a social organization without aggressive confrontations could be key to the initiation of an invasion in this species.

Hydrothermal alteration of Ni-rich sulfides in peridotites of Abu Dahr, Eastern Desert, Egypt: Relationships among minerals in the Fe-Ni-Co-O-S system,fO2 andfS2

AbstractThe Neoproterozoic peridotites of Abu Dahr, Eastern Desert of Egypt, consist mainly of highly depleted harzburgites that have experienced multiple stages of serpentinization (lizarditization and antigoritization) and carbonation/listvenitization in a forearc environment. The Abu Dahr forearc harzburgites are more oxidized than oceanic mantle, with the oxygen fugacity (fO2) values ranging from FMQ+0.41 to FMQ+1.20 (average = +0.60 FMQ), and were equilibrated at temperatures of 910–1217 °C and pressures of 4.1–7.8 kbar. This study has documented for the first time the presence of various Ni-rich Ni-Fe (-Co) sulfide and metal phases along with Fe-oxides/oxyhydroxides in serpentinized-carbonated peridotites of the Abu Dahr forearc. Here I concentrate on the relationship between redox state and Fe-Ni-Co-O-S minerals with emphasis on the role of hydrothermal processes in upgrading magmatic sulfide tenors, desulfurization (sulfur-loss) of magmatic pentlandite and hydrothermal upgrading of the sulfide phases in Abu Dahr forearc environment. The minerals involved are high-Ni pentlandite (Fe4Ni5S8), cobaltian pentlandite (Fe3.47Ni4.78Co0.75S8), heazlewoodite (Fe0.07Ni2.93S2), godlevskite (Fe0.26Ni8.73Co0.01S8), millerite (Fe0.01Ni0.98Cu0.01S), awaruite (Ni75Fe21) and native Ni (Ni93Fe5), and nickeliferous magnetite and goethite. Chalcopyrite is a rare mineral; other Cu-phases, Fe-sulfides and Ni-arsenides/phosphides are not present. Texturally, Ni-sulfide and alloy minerals occur as interstitial disseminated blebs of either solitary phases or composite intergrowths with characteristic replacement textures, documenting strong variations in oxygen and sulfur fugacities (fO2-fS2). Sulfide assemblages are divided into three main facies: (1) pentlandite-rich; (2) godlevskite-rich; and (3) millerite-rich. Textural relationships imply the following sequence: (a) primary pentlandite → cobaltian pentlandite, with partial replacement of the latter by awaruite and/or heazlewoodite along with magnetite; (b) heazlewoodite is replaced by godlevskite, which in turns is replaced by millerite; (c) Ni-rich awaruite breaks down to millerite; and finally, (d) magnetite is completely replaced by goethite. The sulfide mineralogy reflects the magmatic and post-magmatic evolution of the complex. The primary magmatic processes gave rise to pentlandite, whereas the secondary Ni-sulfides together with the metallic alloys formed in response to changing fO2 and fS2 conditions associated with post-magmatic serpentinization and carbonation. Serpentinization-related Ni-Fe-Co remobilization from magmatic olivines resulted in; (1) upgrading the Ni-Co tenors of pre-existing primary pentlandite, and desulfidation to form low-sulfur sulfides (mainly heazlewoodite) and awaruite under extremely low fO2 and fS2 conditions; (2) in situ precipitation of secondary Ni-sulfides in the presence of extra sulfur as aqueous H2S derived from the desulfurization of magmatic pentlandite or native Ni when fS2 approaches 0; (3) transformation from low-sulfur pentlandite- and godlevskite-rich assemblages to the high-sulfur millerite-rich assemblages related to later carbonation with increasing fO2; and (4) partial dehydration of antigorite serpentinites under high-pressure conditions (>1 GPa) generated Ni-rich awaruite in equilibrium with the prograde assemblage antigorite-metamorphic olivine at higher fO2 and fS2 within subduction channel. The mineralogical, chemical, and thermal similarities with other serpentinite-related Ni-sulfides worldwide suggest that Ni minerals in the Fe-Ni-Co-O-S system record changing fO2 and fS2 during progressive serpentinization and carbonation.

Allocation of more reproductive resource to egg size rather than clutch size of gregarious desert locust (Schistocerca gregaria) through increasing oogenesis period and oosorption rate

The desert locust, Schistocerca gregaria, shows a density-dependent reproductive trade-off by laying fewer but larger eggs in crowded conditions (gregarious phase) than in isolated conditions (solitarious phase). However, the physiological mechanisms controlling reproductive resource allocation remain unclear. We examined how egg production processes, including ovulation timing (i.e., oogenesis period), oocyte and ovarian growth rates, and oosorption rate (resorbing developing terminal oocytes), regulate reproductive outputs (egg biomass per clutch, egg size, and clutch size) during a reproductive cycle in S. gregaria by rearing them either under isolated or crowded conditions. We observed a common density-dependent negative correlation between egg size and clutch size, with no significant difference in egg biomass between the two rearing conditions. Dissection of female locusts after different days of oviposition revealed that the daily oocyte growth rate was almost similar between the two rearing conditions, but crowd-reared females ovulated later than isolated-reared ones, resulting in further oocyte growth in the former. Terminal oocytes were renewed by previous penultimate oocytes at the onset of a new reproductive cycle, and oosorption mainly occurred at an early stage in both rearing conditions; however, crowd-reared locusts displayed higher levels of oosorption compared to their isolated-reared counterparts. Crowding induced a high oosorption rate, resulting in a reduced clutch size and a prolonged oogenesis period, which in turn allowed oocytes to intake more yolk, which was probably recycled via oosorption. These results suggest that the length of the oogenesis period and oosorption rate are manipulated by maternal density, and these physiological modifications interactively regulate reproductive trade-off in S. gregaria.

Entropy Amplified solitary phase relative probe on engine oil based hybrid nanofluid

Heat transfer is of vital importance because of its application in industries. A new nanofluid class called "hybrid nanofluid" is being used to boost ordinary fluids' heat transfer capabilities and has a higher heat exponent than nanofluids. The hybrid nanofluids (HNFs) are associated with two-element nanoparticles immersed in a base fluid. The steady hybrid nanofluid flowing and thermal transport characteristics passed overhead a slippery surface are investigated in this research. The impact of nanosolid particle shapes, Porosity material, heat source, viscous dissipative flow, and radiative flux are also involved in this examination. In a regime of partial-differential equations (PDEs), the predominant flow equations are formulated. Keller-box's computational technique is the utilized method to detect the self-similar solution for formulas transformed into ordinary-differential equations (ODEs) through appropriate transmutations. Williamson hybrid nanofluid has been considered for this work, which consists of double diverse kinds of nanoparticle, Copper (Cu) and Silicon dioxide (SiO2) in the rich viscous based fluid of kind EO (Engine Oil). The noteworthy result of this analysis is that the comparing thermal transmission level of such kind of fluid (SiO2Cu/EO) which has progressively more upsurges as compared to traditional nanofluids (Cu-EO). The lamina-shaped elements cause the utmost important thermal conductivity in the boundary- layer, whilst the lowermost thermal conductivity is detected in sphere shaped nanoparticles.

Optimizing Laboratory Rearing of a Key Pollinator, Bombus impatiens.

Simple SummaryRearing insects in captivity is critical for both research and commercial purposes. One group of insects that stands out for their ecological and scientific importance are bumble bees. However, most research studies with bumble bees rely on commercial colonies due to the challenges associated with initiating colonies in the laboratory. This limits the ability to study the early stages of the colony life cycle and the ability to control for variables such as colony age and relatedness. To overcome these challenges, we tested several aspects related to the solitary phase of the North American bumble bee species, Bombus impatiens. In this species, queens emerge by the end of the season, mate, and enter a winter diapause. They then initiate a colony the next spring. We examined the optimal age for mating and how the timing of CO2 narcosis (a technique used to bypass diapause) and social cues post-mating affect queen egg laying. We demonstrate an optimum age for mating in males and females and the importance of worker and pupa presence to egg laying in queens. Overall, our findings indicate that the laboratory rearing of bumble bees can be improved by reducing challenges associated with rearing queens during the solitary phase.Bumble bees are key pollinators for wild and managed plants and serve as a model system in various research fields, largely due to their commercial availability. Despite their extensive use, laboratory rearing of bumble bees is often challenging, particularly during the solitary phase queens undergo before founding a colony. Using a literature survey, we demonstrate that most studies rely on commercially available species that are provided during the colony’s social phase, limiting study on early phases of the life cycle and the ability to control for colony age and relatedness. Laboratory rearing is challenging since the queen solitary phase is less understood compared to the social phase. To overcome this barrier, we examined several aspects related to the queen solitary phase: the effect of age on likelihood of mating, how the timing of CO2 narcosis post-mating (a technique to bypass diapause) affects egg-laying, and whether different social cues affect the success of colony initiation. Our data show an optimum age for mating in both sexuals and decreased egg-laying latency in the presence of workers and pupae. The timing of CO2 narcosis did not significantly affect egg laying in queens. These findings can be incorporated to improve bumble bee rearing for research purposes.

Larvae Crowding Increases Development Rate, Improves Disease Resistance, and Induces Expression of Antioxidant Enzymes and Heat Shock Proteins in Mythimna separata (Lepidoptera: Noetuidae).

High population density (crowding) becomes a stress factor in insects. The oriental armyworm, Mythimna separata (Walker), displays gregarious and solitary phases at high and low population densities, respectively. In this study, we compared life history, disease resistance, and induction of antioxidant enzymes and heat shock protein (HSPs) in two phases of M. separata larvae. Results showed that gregarious larvae had a faster growth rate and lower pupal weight compared to solitary larvae. Furthermore, gregarious individuals exhibited higher survival rates than solitary individuals after Beauveria bassiana infection. The gregarious larvae had higher malondialdehyde content compared to solitary ones, but no differences in total antioxidant capacity were observed between the two larval phases before or after infection. Superoxide dismutase and glutathione peroxidase activities were significantly lower in gregarious M. separata larvae than solitary individuals before infection, but no difference was detected in two phases after infection. However, peroxidase and catalase activities in the two phases showed no difference either before or after infection. Hsp19.8 and Hsp90 expression in gregarious larvae were up-regulated when compared to solitary individuals before or after infection. CuZnSOD expression was not different between the two phases before infection, but it was up-regulated in gregarious ones compared to solitary ones after infection. However, expression of other stress-related genes in gregarious larvae was either repressed or unchanged when compared to solitary individuals before or after infection. Thus, larval crowding changed life history, improved disease resistance of M. separata larvae, and induced variable response of antioxidant enzymes and HSPs to fungal infection.

The role of the neuropeptide [His7]-corazonin on phase-related characteristics in the Central American locust

Density-dependent phase polyphenism in locusts is one of the most extreme forms of phenotypic plasticity. Locusts exist along the continuum between two density-dependent phenotypes that differ in nymphal coloration, behavior, morphology, physiology, and reproduction among others. Nymphs of the solitarious phase, found in low population densities, are usually green, relatively inactive, and avoid each other, while gregarious nymphs, found in high density, exhibit a very obvious yellow/orange background with black patterning, and are highly active and attracted to each other. The multifunctional neuropeptide [His7]-corazonin has been shown to strongly affect black coloration and several other phase-related characteristics in at least two locust species, even though no effect on phase-related behavioral traits has been found. In this study, we investigate the role of [His7]-corazonin in the Central American locust Schistocerca piceifrons (Walker), which evolved density-dependent phase polyphenism independently from the two previously studied locust species. After successfully knocking down the transcript encoding [His7]-corazonin (CRZ) using RNA interference, we show that such a knockdown influences both color and morphometrics in this species, but does not influence phase-related behavioral traits. Our results suggest that the role of [His7]-corazonin is conserved in different locust species. Finally, our study represents the first controlled study of behavioral solitarization in S. piceifrons.

WITHDRAWN: Augmentation of performance and Emission distinctiveness of heavy duty constant pressure combustion engine supplemented through n-butanol-mustard oil-diesel composition

Abstract With the effect of diminution of gasoline yields as well as deadly secretions from the tail pipe of Compression Ignition engines it has become a essential to purse for the substitute for gasoline yields for extended usage. Presently, investigators as well as specialists have come to the decision that biodiesel mixed to the advanced alcohols can be a suitable auxiliary for present condition. Previous surveys have represented that bio diesel as well as advanced alcohol will support for developing the performance as well as disparaging destructive dissipate gases in C.I engine. Present exploration is based on the mixtures of Diesel, Mustard oil and Butanol which are arranged to verify the consequences of mixture towards the performance and Emission features for a C.I engine. In this study, biofuel has been made through solitary phase alkaline transesterification procedure and mixtures of Diesel-Mustard oil and Diesel-Mustard oil-Butanol has been indicated as D90-M10, D80-M20, D80-M10-nB10 and D60-M20-nB20. After this process, the mixtures are examined in a single cylinder, heavy duty C.I engine having graded power yield of 3.93 kW and the output has been compared with pure Diesel. Investigational explorations establishes that mixtures of Mustard oil as well as Butanol can be utilized as a fuel for a heavy duty C.I engine without any modification to the engine.

Characterization and expression analysis of genes encoding three small heat shock proteins in the oriental armyworm, Mythimna separata(Walker).

Small heat shock proteins (sHsps) function in the response of insects to abiotic stress; however, their role in response to biotic stress has been under-investigated. Mythimna separata, the oriental armyworm, is polyphenetic and exhibits gregarious and solitary phases in response to high and low population density, respectively. In this study, three genes were identified encoding sHsps, namely MsHsp19.7, MsHsp19.8 and MsHsp21.4, and expression levels in solitary and gregarious M. separata were compared. The deduced protein sequences of the three MsHsps had molecular weights of 19.7, 19.8 and 21.4 kDa, respectively, and contained a conserved α-crystalline domain. Real-time PCR analyses revealed that the three sHsps were transcribed in all developmental stages and were dramatically up-regulated at the 6th larval stage in gregarious individuals. Expression of the three MsHsps was variable in different tissues of 6th instar larvae, but exhibited consistent up- and down-regulation in the hindgut and Malpighian tubules of gregarious individuals, respectively. In addition, MsHsp19.7 and MsHsp19.8 were significantly induced when solitary forms were subjected to crowding for 36 h, but all three MsHsps were down-regulated when gregarious forms were isolated. Our findings suggest that population density functions as a stress factor and impacts MsHsps expression in M. separata.

Solving optimal reactive power problem by Shark Reek, Amplified Locust Search and White Rhinoceros Algorithms

ABSTRACT In this work Shark Reek Algorithm (SRA), Amplified Locust Search (ALS) optimisation algorithm, White Rhinoceros Algorithm (WRA) has been projected to solve optimal reactive power problem. SRA is stimulated by the shark’s capacity to hunt based on its stench sense. Blood flows in the sea when a fish injured into the sea and this treated as search space. Normally the odour particles are high near to the wounded fish. . Secondly Amplified Locust Search (ALS) optimisation algorithm projected to solve the problem. In Locust Search explore agents alter their position at every generation of the algorithm throughout its evolution. Two behavioural phases: solitary phase and social phase are implemented. In Amplified Locust Search (ALS) optimisation algorithm as an alternative of applying both the solitary and social phase operators in the same iteration. Then White Rhinoceros Algorithm (WRA) has been applied to solve the problem. White rhinoceros are one among biggest mammals, which generally live on in leafy materials. Synoptic model and population size modernising model are designed in the projected optimisation algorithm. In this work, White Rhinoceros Ease Index (WREI) is utilised to calculate the righteousness of feasible solution. Proposed SRA, ALS, WRA algorithms is tested in IEEE 30, bus system- real power loss minimisation, voltage deviation minimisation, and voltage stability index enhancement has been attained. Then the Proposed SRA, ALS, WRA algorithms has been tested in standard IEEE 14, 30, 57, 300 bus test systems without considering the voltage stability index. Projected algorithms reduced the power loss effectively and control variables are within the limits.

Solitary phase waves in a chain of autonomous oscillators.

In the present paper, we study phase waves of self-sustained oscillators with a nearest-neighbor dispersive coupling on an infinite lattice. To analyze the underlying dynamics, we approximate the lattice with a quasi-continuum (QC). The resulting partial differential model is then further reduced to the Gardner equation, which predicts many properties of the underlying solitary structures. Using an iterative procedure on the original lattice equations, we determine the shapes of solitary waves, kinks, and the flat-like solitons that we refer to as flatons. Direct numerical experiments reveal that the interaction of solitons and flatons on the lattice is notably clean. All in all, we find that both the QC and the Gardner equation predict remarkably well the discrete patterns and their dynamics.

Juvenile hormone suppresses aggregation behavior through influencing antennal gene expression in locusts.

Animals often exhibit dramatically behavioral plasticity depending on their internal physiological state, yet little is known about the underlying molecular mechanisms. The migratory locust, Locusta migratoria, provides an excellent model for addressing these questions because of their famous phase polyphenism involving remarkably behavioral plasticity between gregarious and solitarious phases. Here, we report that a major insect hormone, juvenile hormone, is involved in the regulation of this behavioral plasticity related to phase change by influencing the expression levels of olfactory-related genes in the migratory locust. We found that the treatment of juvenile hormone analog, methoprene, can significantly shift the olfactory responses of gregarious nymphs from attraction to repulsion to the volatiles released by gregarious nymphs. In contrast, the repulsion behavior of solitarious nymphs significantly decreased when they were treated with precocene or injected with double-stranded RNA of JHAMT, a juvenile hormone acid O-methyltransferase. Further, JH receptor Met or JH-response gene Kr-h1 knockdown phenocopied the JH-deprivation effects on olfactory behavior. RNA-seq analysis identified 122 differentially expressed genes in antennae after methoprene application on gregarious nymphs. Interestingly, several olfactory-related genes were especially enriched, including takeout (TO) and chemosensory protein (CSP) which have key roles in behavioral phase change of locusts. Furthermore, methoprene application and Met or Kr-h1 knockdown resulted in simultaneous changes of both TO1 and CSP3 expression to reverse pattern, which mediated the transition between repulsion and attraction responses to gregarious volatiles. Our results suggest the regulatory roles of a pleiotropic hormone in locust behavioral plasticity through modulating gene expression in the peripheral olfactory system.

Design and testing of stability improvement of nine multi-level H-Inverter for distribution system

<p class="Abstract">In this article, a solitary phase nine-level series connected H-Bridge powered by photovoltaic MPPT based SHAPF in view of basic controller is proposed. SRF is utilized for reference input current extraction and to create pulses for the SHAPF. The principle point of the cascaded bridge is to dispense harmonics, enhance power factor and reactive energy compensation of the single-phase distribution framework. The suggested control calculation has two parts, changing the load current into stationary reference outline directions and estimation of peak amplitude of load currents. Consequently, a basic and dependable controller effortlessly of execution was created. The calculation for single-phase SHAF is intending to perform with exact tracking performance under step changes in load currents and to give great dynamic compensation. In this article, synchronous reference theory PLL with Inverse-Park change is adopted for producing quadrature part of current. The execution of the control calculation is tried and assessed utilizing MATLAB/Simulink tool.</p>

JumpDetector: An automated monitoring equipment for the locomotion of jumping insects.

Continuous jumping behavior, a kind of endurance locomotion, plays important roles in insect ecological adaption and survival. However, the methods used for the efficient evaluation of insect jumping behavior remain largely lacking. Here, we developed a locomotion detection system named JumpDetector with automatic trajectory tracking and data analysis to evaluate the jumping of insects. This automated system exhibits more accurate, efficient, and adjustable performance than manual methods. By using this automatic system, we characterized a gradually declining pattern of continuous jumping behavior in 4th‐instar nymphs of the migratory locust. We found that locusts in their gregarious phase outperformed locusts in their solitary phase in the endurance jumping locomotion. Therefore, the JumpDetector could be widely used in jumping behavior and endurance locomotion measurement.

No second chances for pollen-laden queens?

Bumble bees are eusocial, yet queens are solitary for much of their lives. Little is known about the stages in the solitary phase of queens, including the factors that influence successful initiation of nests. One anecdotal recommendation suggests that wild-caught queens are less likely to initiate nests if they are captured while carrying pollen loads. Queens that are collecting pollen have already chosen a nest site and are either preparing to lay their first clutch of eggs, have already begun oviposition, or are provisioning developing brood. Although there is a conservation-based argument for leaving these queens to their own devices, we were interested in the biological aspect of this: if a queen has already initiated a nest in the wild, will she initiate another one in captivity? In 2016 and 2017, 960 queens of five species were captured, and the presence or absence of corbicular loads of pollen was noted. Each queen was then placed in an artificial nest and provided with unlimited food for 21 days. Nests were monitored for brood presence daily, and rates of nest initiation (brood production) were compared between queens captured with and without pollen loads. Nest initiation rates varied among species, as did the influence of pollen-collecting behavior at the time of capture. Pollen-laden Bombus occidentalis queens were less likely to lay eggs, yet B. bifarius and B. vosnesenskii queens with pollen had a greater chance of initiating a captive nest. These results should inform both commercial and conservation efforts.