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Molecules (Basel, Switzerland) Jun 2024In this study, the chemical composition, repellent, and oviposition deterrent effects of five plant essential oils (EOs) extracted from (Verbenaceae), (Anacardiaceae),...
In this study, the chemical composition, repellent, and oviposition deterrent effects of five plant essential oils (EOs) extracted from (Verbenaceae), (Anacardiaceae), (Myrtaceae), (Asteraceae), and (Lamiaceae) were evaluated against , , and . When tested at 33.3 µg/cm, , , , and were effective repellents against (89%, 91%, 90%, and 51% repellency, respectively), but they were less repellent against (66%, 86%, 59%, and 49% repellency, respectively). Interestingly, , , , and exhibited 100% repellency against at 33.3 μg/cm. In time-span bioassays performed at 333 μg/cm, the EO of exhibited 100% repellence against and for up to 15 min and against for 75 min. The oviposition bioassays revealed that exhibited the highest activity, showing 85%, 59%, and 89% oviposition deterrence against , , and , respectively. The major compounds of , , and were -β-caryophyllene (16.7%), α-pinene (15.5%), and 1,8-cineole (38.1%), respectively. In conclusion, the and EOs have the potential to be natural mosquito repellents.
Topics: Animals; Oils, Volatile; Insect Repellents; Oviposition; Aedes; Culex; Anopheles; Culicidae; Plant Oils; Lantana; Anacardiaceae; Plant Extracts; Female
PubMed: 38893531
DOI: 10.3390/molecules29112657 -
International Journal of Molecular... Jun 2024The occurrence of ovarian dysfunction is often due to the imbalance between the formation of reactive oxygen species (ROS) and the ineffectiveness of the antioxidative...
The occurrence of ovarian dysfunction is often due to the imbalance between the formation of reactive oxygen species (ROS) and the ineffectiveness of the antioxidative defense mechanisms. Primary sources of ROS are respiratory electron transfer and the activity of NADPH oxidases (NOX) while superoxide dismutases (SOD) are the main key regulators that control the levels of ROS and reactive nitrogen species intra- and extracellularly. Because of their central role SODs are the subject of research on human ovarian dysfunction but sample acquisition is low. The high degree of cellular and molecular similarity between ovaries and human ovaries provides this model organism with the best conditions for analyzing the role of ROS during ovarian function. In this study we clarify the localization of the ROS-producing enzyme dNox within the ovaries of and by a tissue-specific knockdown we show that dNox-derived ROS are involved in the chorion hardening process. Furthermore, we analyze the dSod3 localization and show that reduced activity of dSod3 impacts egg-laying behavior but not the chorion hardening process.
Topics: Animals; Drosophila melanogaster; Female; Superoxide Dismutase; Reactive Oxygen Species; Drosophila Proteins; Ovary; NADPH Oxidases; Reproduction; NADPH Oxidase 5; Oviposition; Chorion
PubMed: 38892326
DOI: 10.3390/ijms25116138 -
International Journal of Molecular... May 2024The effect of pesticides on insects is often discussed in terms of acute and chronic toxicity, but an important and often overlooked aspect is the impact of sublethal... (Review)
Review
The effect of pesticides on insects is often discussed in terms of acute and chronic toxicity, but an important and often overlooked aspect is the impact of sublethal doses on insect physiology and behavior. Pesticides can influence various physiological parameters of insects, including the innate immune system, development, and reproduction, through a combination of direct effects on specific exposed tissues and the modification of behaviors that contribute to health and reproductive success. Such behaviors include mobility, feeding, oviposition, navigation, and the ability to detect pheromones. Pesticides also have a profound effect on insect learning and memory. The precise effects depend on many different factors, including the insect species, age, sex, caste, physiological condition, as well as the type and concentration of the active ingredients and the exposure route. More studies are needed to assess the effects of different active ingredients (and combinations thereof) on a wider range of species to understand how sublethal doses of pesticides can contribute to insect decline. This review reflects our current knowledge about sublethal effects of pesticides on insects and advancements in the development of innovative methods to detect them.
Topics: Animals; Insecta; Pesticides; Reproduction; Behavior, Animal
PubMed: 38892195
DOI: 10.3390/ijms25116007 -
International Journal of Molecular... May 2024Carbon dioxide (CO) released by plants can serve as a cue for regulating insect behaviors. is a widely distributed forestry pest that may use CO as a cue for foraging...
Carbon dioxide (CO) released by plants can serve as a cue for regulating insect behaviors. is a widely distributed forestry pest that may use CO as a cue for foraging and oviposition. However, the molecular mechanism underlying its ability to sense CO has not been elucidated. Our initial study showed that CO is significantly attractive to adults. Subsequently, 44 gustatory receptors () were identified using transcriptome data, and 3 candidate CO receptors that are specifically expressed in the labial palps were identified. In vivo electrophysiological assays revealed that the labial palp is the primary organ for CO perception in , which is similar to findings in other lepidopteran species. By using the oocyte expression system, we showed that the and co-expressions produced a robust response to CO, but had an inhibitory effect on CO perception. Finally, immunohistochemical staining revealed sexual dimorphism in the CO-sensitive labial pit organ glomerulus (LPOG). Taken together, our results clarified the mechanism by which sense CO, laying the foundation for further investigations into the role of CO in the rapid spread of .
Topics: Animals; Carbon Dioxide; Insect Proteins; Female; Receptors, Cell Surface; Male; Moths; Transcriptome; Oocytes; Phylogeny
PubMed: 38892175
DOI: 10.3390/ijms25115987 -
Frontiers in Plant Science 2024Silicon (Si) uptake is generally beneficial for plants that need protection from insect herbivores. In pursue of mechanisms involved in Si-mediated defense, we...
Silicon (Si) uptake is generally beneficial for plants that need protection from insect herbivores. In pursue of mechanisms involved in Si-mediated defense, we comprehensively explored the impact of Si on several defensive and metabolic traits in rice exposed to simulated and real herbivory of Duponchel larvae. Hydroponic experiments showed that Si-deprived rice supplemented with Si 72 h prior to insect infestation were similarly resistant to larvae as plants continuously grown in Si-containing media. Both Si and herbivory altered primary metabolism in rice, including the levels of several sugars, amino acids, and organic acids. While the accumulation of sugars was generally positively correlated with Si presence, multiple amino acids showed a negative correlation trend with Si supplementation. The levels of secondary metabolites, including isopentylamine, -coumaroylputrescine and feruloylputrescine, were typically higher in the leaves of Si-supplemented plants exposed to herbivory stress compared to Si-deprived plants. In addition, simulated herbivory treatment in Si-supplemented plants induced more volatile emissions relative to Si-deprived plants, which was consistent with the increased transcripts of key genes involved in volatile biosynthesis. In ecological interactions, Si alone did not affect the oviposition choice of but gravid females showed a significant preference for simulated herbivory-treated/Si-deprived compared to Si-supplemented plants. Our data suggest that apart from mechanical defense, Si may affect rice metabolism in multiple ways that might enhance/modulate defense responses of rice under herbivory stress.
PubMed: 38872888
DOI: 10.3389/fpls.2024.1399562 -
PLoS Genetics Jun 2024Tardigrades are small aquatic invertebrates known for their remarkable tolerance to diverse extreme stresses. To elucidate the in vivo mechanisms underlying this...
Tardigrades are small aquatic invertebrates known for their remarkable tolerance to diverse extreme stresses. To elucidate the in vivo mechanisms underlying this extraordinary resilience, methods for genetically manipulating tardigrades have long been desired. Despite our prior success in somatic cell gene editing by microinjecting Cas9 ribonucleoproteins (RNPs) into the body cavity of tardigrades, the generation of gene-edited individuals remained elusive. In this study, employing an extremotolerant parthenogenetic tardigrade species, Ramazzottius varieornatus, we established conditions that led to the generation of gene-edited tardigrade individuals. Drawing inspiration from the direct parental CRISPR (DIPA-CRISPR) technique employed in several insects, we simply injected a concentrated Cas9 RNP solution into the body cavity of parental females shortly before their initial oviposition. This approach yielded gene-edited G0 progeny. Notably, only a single allele was predominantly detected at the target locus for each G0 individual, indicative of homozygous mutations. By co-injecting single-stranded oligodeoxynucleotides (ssODNs) with Cas9 RNPs, we achieved the generation of homozygously knocked-in G0 progeny, and these edited alleles were inherited by G1/G2 progeny. This is the first example of heritable gene editing in the entire phylum of Tardigrada. This establishment of a straightforward method for generating homozygous knockout/knock-in individuals not only facilitates in vivo analyses of the molecular mechanisms underpinning extreme tolerance, but also opens up avenues for exploring various topics, including Evo-Devo, in tardigrades.
Topics: Animals; Tardigrada; CRISPR-Cas Systems; Gene Editing; Parthenogenesis; Homozygote; Female; Gene Knock-In Techniques; Gene Knockout Techniques; Alleles
PubMed: 38870088
DOI: 10.1371/journal.pgen.1011298 -
PloS One 2024A significant crop pest, Mythimna loreyi, migrates annually to Korea and has been frequently observed in rice and corn fields. However, the phenology of this pest,...
Assessment of the occurrence of the second generation of Mythimna loreyi Duponchel (Lepidoptera: Noctuidae) using temperature-dependent developmental and oviposition models.
A significant crop pest, Mythimna loreyi, migrates annually to Korea and has been frequently observed in rice and corn fields. However, the phenology of this pest, particularly in relation to its ecological interactions and host crop seasons in Korea, remains poorly understood. This study aims to clarify the timing of the second generation of M. loreyi in Korea to enhance pest management strategies. To achieve this, we developed temperature-dependent models for developmental and ovipositional rates, studying these processes across five constant temperatures (15, 20, 25, 30, and 35°C). Our models, which showed a high correlation with observed data (r2 ≥ 0.93), include a theoretical approach that combines the developmental variation of immatures with the necessary degree-days for 50% egg laying and complete egg development. These predictions allow for the forecasting of the second generation's occurrence, with relatively small deviations (one to three days) observed at two different field sites. The insights from this study are critical for both understanding the ecology of M. loreyi and for informing practical management decisions, such as optimal placement of barriers to prevent immigration and strategies for controlling local populations.
Topics: Animals; Oviposition; Temperature; Female; Republic of Korea; Moths; Models, Biological; Seasons
PubMed: 38865352
DOI: 10.1371/journal.pone.0303841 -
Parasites & Vectors Jun 2024Salinity, exacerbated by rising sea levels, is a critical environmental cue affecting freshwater ecosystems. Predicting ecosystem structure in response to such changes...
BACKGROUND
Salinity, exacerbated by rising sea levels, is a critical environmental cue affecting freshwater ecosystems. Predicting ecosystem structure in response to such changes and their implications for the geographical distribution of arthropod disease vectors requires further insights into the plasticity and adaptability of lower trophic level species in freshwater systems. Our study investigated whether populations of the mosquito Culex pipiens, typically considered sensitive to salt, have adapted due to gradual exposure.
METHODS
Mesocosm experiments were conducted to evaluate responses in life history traits to increasing levels of salinity in three populations along a gradient perpendicular to the North Sea coast. Salt concentrations up to the brackish-marine transition zone (8 g/l chloride) were used, upon which no survival was expected. To determine how this process affects oviposition, a colonization experiment was performed by exposing the coastal population to the same concentrations.
RESULTS
While concentrations up to the currently described median lethal dose (LD) (4 g/l) were surprisingly favored during egg laying, even the treatment with the highest salt concentration was incidentally colonized. Differences in development rates among populations were observed, but the influence of salinity was evident only at 4 g/l and higher, resulting in only a 1-day delay. Mortality rates were lower than expected, reaching only 20% for coastal and inland populations and 41% for the intermediate population at the highest salinity. Sex ratios remained unaffected across the tested range.
CONCLUSIONS
The high tolerance to salinity for all key life history parameters across populations suggests that Cx. pipiens is unlikely to shift its distribution in the foreseeable future, with potential implications for the disease risk of associated pathogens.
Topics: Animals; Culex; Female; Oviposition; Salinity; Male; Ecosystem; Salt Tolerance; Fresh Water; Life History Traits; Mosquito Vectors; Lethal Dose 50; Sodium Chloride
PubMed: 38858771
DOI: 10.1186/s13071-024-06268-8 -
Animal : An International Journal of... Jun 2024To address multiple issues impacting the climate imbalance, insects, and in particular Tenebrio molitor, represent now a promising alternative for producing high-quality...
To address multiple issues impacting the climate imbalance, insects, and in particular Tenebrio molitor, represent now a promising alternative for producing high-quality protein products with low environmental impact. As with any new species farmed on an industrial scale, insect breeding production must be improved through the accumulation of knowledge on rearing techniques and genetic management. Little information on the inheritance of agronomically interesting traits, dedicated to Tenebrio molitor, is available. This study aims to decipher the genetic parameters (heritability and genetic correlations) of reproduction, larval growth and survival, pupation rate and developmental time from a reference population made up of 1 931 sib-groups reared under pedigree, in controlled and stable environments and generated with single pair mating. Considering all sib-groups, 29 599 offspring have been generated and phenotyped over four generations to support this study and provide enough data to estimate, under linear animal models, the additive genetic and common environmental effects. Phenotypic analyses underlined an important variability among sib-groups and individuals, as for the total oviposition during 4 weeks counting (0-680 eggs, min - max, respectively) or larval body mass 63 days posteclosion (36.3-206.8 mg, min - max, respectively). Moderate to important heritability values have been obtained and ranged from 0.17 to 0.54 for reproduction phenotypes, 0.10-0.44 for growth parameters, 0.06-0.22 for developmental time and 0.10-0.17 for larval survival rates. The proportion of phenotypic variance explained by the environmental part varyies from 0.10 to 0.36 for reproductive traits, from 0.17 to 0.38 for growth parameters, from 0.06 to 0.36 for developmental time and 0.17-0.22 for survival rates. Genetic correlations underline relationships among phenotypes such as the trade-off between developmental time from egg to pupae and pupae weight (r = 0.48 ± 0.06). These important phenotypic variations coupled with promising heritability values pave the road for future breeding programs in Tenebrio molitor.
Topics: Animals; Tenebrio; Female; Male; Phenotype; Larva; Breeding; Reproduction; Oviposition
PubMed: 38850579
DOI: 10.1016/j.animal.2024.101197 -
PloS One 2024In the polyphagous insect Monolepta signata (M. signata) (Coleoptera: Chrysomelidae), antennae are important for olfactory reception used during feeding, mating, and...
In the polyphagous insect Monolepta signata (M. signata) (Coleoptera: Chrysomelidae), antennae are important for olfactory reception used during feeding, mating, and finding a suitable oviposition site. Based on NextSeq 6000 Illumina sequencing, we assembled the antennal transcriptome of mated M. signata and described the first chemosensory gene repertoire expressed in this species. The relative expression levels of some significant chemosensory genes were conducted by quantitative real-time PCR. We identified 114 olfactory-related genes based on the antennal transcriptome database of M. signata, including 21 odorant binding proteins (OBPs), six chemosensory proteins (CSPs), 46 odorant receptors (ORs), 15 ionotropic receptors (IRs), 23 gustatory receptors (GRs) and three sensory neuron membrane proteins (SNMPs). Blastp best hit and phylogenetic analyses showed that most of the chemosensory genes had a close relationship with orthologs from other Coleoptera species. Overall, this study provides a foundation for elucidating the molecular mechanism of olfactory recognition in M. signata as well as a reference for the study of chemosensory genes in other species of Coleoptera.
Topics: Animals; Coleoptera; Arthropod Antennae; Transcriptome; Receptors, Odorant; Phylogeny; Insect Proteins; Female; Gene Expression Profiling
PubMed: 38848419
DOI: 10.1371/journal.pone.0301177