Mechanism of locust egg susceptibility to diafenthiuron: micropyle permeation and serosal cuticle disruption lead to embryonic lethality.

Drosophila as a model to study autophagy during oogenesis.

ABSTRACTPreimplantation genetic testing for aneuploidies (PGTA) diagnoses chromosomal abnormalities and can be complemented by cumulus cell transcriptional analysis to assess egg and ovarian quality and development during embryo culture. In addition to selecting the best available embryo, intrauterine administration of platelet‐rich plasma (PRP) and correction of insulin resistance (IR) through nutritional intervention can improve endometrial quality. This case report examines the potential feasibility of combining in vitro fertilization (IVF) with four techniques to achieve a viable pregnancy. A couple with a prior successful IVF pregnancy was seeking a second pregnancy. The patient was diagnosed with polycystic ovary syndrome (BMI = 24.5 kg/m2), whereas her partner had teratozoospermia. For the first IVF cycle, using PGTA, we confirmed that only euploid embryos were transferred. A hysteroscopic examination confirmed a lack of endometrial competence, and treatment with autologous intrauterine PRP improved endometrial receptivity; however, after a single‐embryo transfer, the embryo did not implant. The patient underwent a nutritional intervention to improve insulin resistance with a low‐carb dietary intervention (carbohydrates < 50 g/day, protein 1.5 g/day) that reduced insulin resistance after 2 weeks. For the next IVF cycle, the low‐carb dietary intervention was continued, along with another PRP application, and the cumula cells transcriptional analysis was performed in addition to PGTA, identifying two optimal euploid embryos. This time, embryo implantation occurred (β‐hCG: 362.0 mIU/mL). The pregnancy ended at 39 weeks, with a healthy male baby (length: 53 cm; weight: 3465 g; Apgar 8/9). In conclusion, using molecular techniques for embryo selection (cumula analysis and PGTA) and interventions to improve endometrial function (PRP and a dietary intervention) are an effective strategy that strengthens IVF and increases the likelihood of achieving a viable pregnancy.

Mutualistic traits are frequently associated with vertically transmitted symbionts, in part because repeated interactions can align host and symbiont fitness. However, how such traits emerge in symbionts combining vertical and horizontal transmission remains unclear. Here we show that Ascogregarina taiwanensis, previously described as a weak horizontally transmitted parasite of the Asian tiger mosquito (Aedes albopictus), also displays mutualistic traits that enhance mosquito reproduction. Infected females show improved embryogenesis and an extended egg-laying period, while most pseudo-vertically transmit oocysts to their progeny at oviposition sites. This interaction ultimately produces larger larvae that are more frequently infected by As. taiwanensis. Dual transcriptomic analyses further reveal that early oogenesis in infected females involves increased nitrogen metabolism in both partners, enhanced detoxification of blood waste, and activation of egg development pathways. These changes improve assimilation of blood proteins essential for egg production. Together, our results illustrate how physiological coupling during reproduction, combined with mother-biased transmission, can generate mutualistic traits within an interaction that also retains parasitic features, blurring the boundary between parasitism and mutualism.

ABSTRACT Helicoverpa armigera (Hübner) is a major lepidopteran pest of chickpea, with its development and reproduction strongly influenced by temperature. This study examined the development, survival and reproduction of H. armigera reared on chickpea under constant temperatures ranging from 14°C to 36°C. Life table parameters were estimated along with linear and six non-linear thermal models to identify critical thresholds and heat requirements. Results showed that fecundity peaked at 27°C (532 eggs/female) and declined at higher temperatures, while the intrinsic rate of increase (r m ) was highest at 30°C. Linear regression analysis estimated the lower temperature threshold (T min ) for egg development at 7.71°C, while T min for larval instars ranged from 4.19°C to 10.52°C. Embryonic development required 74.07 degree-days. Among the six non-linear temperature development models tested, the Lactin-2 model yielded the most biologically realistic estimates of T min , optimal temperature (T opt ), and upper threshold (T max ), and showed the best goodness-of-fit based on AIC and related statistics. These results provide reliable temperature-based developmental and phenological models for H. armigera on chickpea, supporting better prediction of pest population dynamics and more precise timing of integrated pest management under variable climatic conditions.

Functional disruption of CYP4CE1 impairs egg development and reproductive capacity in Nilaparvata lugens.

IntroductionTicks are hematophagous ectoparasites that must overcome significant physiological challenges during blood feeding. These include managing oxidative stress, detoxifying host-derived molecules, and reallocating energy to support digestion, tissue remodeling, and reproduction.MethodsIn this study, we conducted a de novo transcriptome assembly and genome-wide transcriptional profiling of female Ixodes persulcatus ticks at three key feeding stages: unfed, semi-engorged, and fully engorged. Functional annotation and Gene Ontology (GO) enrichment analyses were conducted to characterize stage-associated transcriptional changes, with a focus on metabolic detoxification and antioxidant systems.Results and discussionWe generated a reference transcriptome containing 56,900 unigenes. Comprehensive analyses of metabolic detoxification and antioxidant systems revealed species-specific expansions in key supergene families such as cytochrome P450s and glutathione S-transferases. The expression profiles across feeding stages revealed pronounced physiological changes in response to blood meal, and GO enrichment analysis showed that these changes were mainly involved in blood acquisition, nutrient metabolism, respiratory processes, hormone synthesis, egg development, immune responses, ROS detoxification, transcription and translation. These findings offer new insights into the molecular physiology of tick hematophagy and provide a valuable resource for future studies on stress responses and metabolic regulation in ticks.

Ferns are the second most diverse lineage of vascular plants worldwide and are particularly abundant in tropical forests. However, the ecological significance of such remarkable diversity has been often underestimated. In this article, we report for the first time the observation of ferns, specifically Polytaenium cajenense (Desv.) Benedict (Polypodiopsida, Pteridaceae), serving as oviposition sites for katydids ( Stilpnochlora sp., Orthoptera: Tettigoniidae) in a remnant of humid tropical forest in Brazil. The identification of the katydid was performed by experts based on egg morphology. The eggs were laid along the margin of the laminae, on the abaxial surface. Interestingly, the eggs seemed to be deposited inside the lamina, and after the oviposition, part of the leaf began a senescence process that exposed the eggs. Phaneropterine katydids are typically generalists regarding plant species or family when it comes to oviposition, but they seem to select material with suitable mechanical properties (e.g. high thickness and stability). We suggest that future experimental studies should include ferns in oviposition tests for katydids, examining how foliar traits such as leaf thickness, orientation, water content, and leaf size influence substrate selection. Future studies should also explore the bidirectional effects between plants and insect eggs, such as phytochemical changes and the production of ovicidal substances, as well as alterations in photosynthetic activity and secondary metabolism. We propose the hypothesis that ferns, which are plants that predominantly occur in low‐light habitats, may provide benefits for egg development in katydids by preventing overheating and dehydration. Our article highlights the potential ecological role of ferns as oviposition sites for katydids.

Stress response of Carcinoscorpius rotundicauda eggs to Bacillus thuringiensis contamination in tropical coast of Peninsular Malaysia.

Sphingomyelin synthase (SMS) is a key enzyme in sphingolipid metabolism that catalyzes the synthesis of sphingomyelin (SM). The potential roles of SMS involved in the egg development and female fecundity on the tremendous pest mite Panonychus citri, however, remain unknown. In this study, we determined the function of sphingomyelin synthase gene in P. citri across different developmental stages. We silenced the PcSMS in adult females of P. citri via feeding on detached citrus leaves that absorbed dsRNAs. The survival rates and lifespan, along with the expressions of ROS and apoptosis genes were significantly changed. Additionally, fecundity and oviposition periods of P. citri were shortened. The expression levels of vitellogenin and its receptor genes were downregulated. Knockdown of PcSMS also affected egg hatching, resulting in developmental delays and egg lethal phenotypes. Our findings shed light on the metabolism underlying the biological functions of egg development and adult females fecundity of P. citri and render lipid metabolism the attractive target for biopesticide to control citrus spider mite.

NR5A nuclear receptors coordinately regulate locust metamorphic transition and fecundity.

Comparative evaluation of the ovicidal activity of Azadirachta indica and its green synthesized silver nanoparticles against Fasciola gigantica eggs.

Comparison of transcriptomics and proteomics revealed distinct molecular mechanisms underlying egg development of Culter alburnus between northern and southern China.

ABSTRACT Hydropeaking, associated with flexible hydropower, produces frequent and dramatic water‐level fluctuations causing repeated drying of shallow areas near river banks and gravel bars. These marginal habitats are crucial for the reproduction of many aquatic and semi‐aquatic species including insects, whose complex life cycles involve transitions between aquatic and terrestrial environments. The sensitivity of stream insects to sub‐daily variation in flow velocity and water levels induced by hydropeaking has mainly been assessed for larvae, whereas the sensitivity of adults and eggs remains largely unknown. For species that attach their egg masses to substrates in shallow waters, fluctuating water levels could expose eggs to air, causing desiccation and mortality. Such hydropeaking‐driven constraints may determine population‐level reproductive success and potentially lead to population bottlenecks. The aim of this study was to determine the sensitivity of stream insect eggs to dry phases. An experiment was performed with Baetis spp. mayfly egg masses in flumes. Egg masses from a wild population were exposed to one of 10 treatments: a dry phase lasting between 1 and 18 h or a control treatment with no dry phase. The treatment was followed by an incubation period in controlled conditions allowing for development and hatching of viable eggs. The hatching proportion was calculated for each individual egg mass based on automated counting of the total number of eggs per mass and manual counting of the number of either hatched or unhatched eggs per mass. A mean of 88%–98% of eggs hatched after 0–5 h dry phases. The proportion declined to 45% after 6 h then to near zero after 9 h dry phases. Dense hyphae developed on egg masses exposed to dry phases lasting 6–18 h. Our study provides some of the first estimates of stream insect egg mass responses to dry phases under optimal and reproducible controlled conditions. Hatching failure at dry‐phase durations ≥ 6 h was likely due to desiccation‐induced egg mortality, which then allowed for the growth of aquatic oomycete hyphae, stream‐dwelling decomposers of organic matter. We highlight the need to consider impacts of flow regulation—and specifically, artificial dry phases associated with hydropeaking operations—on all life stages of aquatic organisms to inform sustainable management strategies that support biodiversity within regulated rivers.

Abstract This study evaluated the functional response and life table parameters of the predator Orius vicinus (Ribaut) (Hemiptera: Anthocoridae) when fed on immature stages of the polyphagous pest Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae). Biological and life table parameters, including development, survival, reproduction, and population growth rates, were assessed using two-sex age–stage life table analysis. Functional responses of adult O. vicinus to the egg, larval, and pupal stages of B. tabaci were determined separately under controlled conditions of 26 ± 1 °C, 60 ± 10% relative humidity (RH), and a 16:8 h light: dark (L: D) photoperiod. Results showed that egg development lasted 4.67 ± 0.06 days, total nymphal development was 13.65 ± 0.13 days with a survival rate of 77.32%, and mean fecundity per female was 60.89 ± 2.76 eggs. Female and male adult longevities were 16.95 ± 0.55 and 12.27 ± 0.54 days, respectively. Adult preoviposition period (APOP) and total preoviposition period (TPOP) were 4.14 ± 0.12 and 22.7 ± 0.23 days, respectively, while the oviposition period lasted 11.23 ± 0.53daysThe estimated life table parameters were the intrinsic rate of increase ( r ) of 0.113 day⁻¹, the net reproductive rate ( R 0 ) of 24.8 offspring, the finite rate of increase ( λ ) of 1.12 day⁻¹, and the mean generation time ( T ) of 28.4 days. Functional response analysis revealed a Type III response to eggs and larval stages, and a Type II response to pupae. These results indicate that O. vicinus could be effectively integrated into Biological control programs against B. tabaci .

Polycystic ovary syndrome (PCOS) is a complex reproductive-endocrine disorder characterized by impaired folliculogenesis, anovulation, and hormonal imbalance. While PNX-14 is known as a hypothalamic peptide that modulates GnRH signaling, emerging evidence indicates its local ovarian expression, particularly in granulosa and luteal cells, suggesting potential peripheral roles in follicular development. This study aimed to evaluate the therapeutic potential of PNX-14 in a dehydroepiandrosterone (DHEA)-induced rat model of PCOS, with a focus on its potential peripheral effects on ovarian tissue. Female rats were divided into control, PCOS, and PCOS + PNX-14 (2.5, 5, or 30 nmol) groups. PCOS was induced by DHEA administration (60 mg/kg/day, s.c.) for 21 days. Vaginal cytology, hormone assays (FSH, LH, E2, P4, and testosterone), histological analysis, PCNA immunohistochemistry, and western blot were performed. DHEA-induced PCOS rats exhibited disrupted estrous cycles, suppressed gonadotropins and estradiol, and polycystic ovarian morphology with extensive follicular atresia and reduced PCNA expression. PNX-14 treatment, particularly at 5 nmol, significantly improved estrous cyclicity, restored primordial and antral follicle populations, reduced atretic and cystic follicles, and normalized PCNA levels in granulosa cells. Serum hormones showed trends toward recovery without consistent statistical significance after 3 days of treatment. This study provides the first in vivo evidence that peripheral administration of this peptide ameliorates key morphological and cellular features of PCOS in rats, primarily by enhancing granulosa cell proliferation and early folliculogenesis. These findings support further investigation into PNX-14 as a novel therapeutic candidate as a local ovarian modulator for PCOS, potentially offering disease-modifying effects beyond conventional symptom-targeted therapies. PCOS is a leading cause of infertility and affects millions of women worldwide. It disrupts normal egg development, causing hormonal imbalances and cyst formation in the ovaries. Current treatments mainly control symptoms but do not repair the ovary itself. We investigate PNX-14, a natural peptide present in the brain and ovary that supports early egg growth. We tested this peptide found in the brain and ovary that supports early egg growth, in a well-established rat model of PCOS. After three days of treatment, it improved ovarian structure and restored regular reproductive cycling. Importantly, it significantly reduced degenerating follicles, helping to preserve healthy early-stage follicles. These benefits occurred even though major blood hormone levels were largely unchanged, suggesting that this peptide acts locally within the ovary. This is the first in vivo evidence that it can directly counter key cellular and structural damage caused by PCOS. The findings highlight PNX-14 as a potential new therapy to protect ovarian health and improve fertility in people with PCOS.

During insect oogenesis, follicular cells (FCs) typically undergo the endocycle to become polyploid, thereby supporting oocyte development. The brown planthopper (BPH, Nilaparvata lugens), one of the most destructive rice pests, exhibits remarkable fecundity. However, the polyploidization of FCs and its regulatory mechanisms remain poorly understood. Here, we demonstrate that 92.3% of FCs become binucleate via endomitosis at stage 4 of oogenesis, followed by a significant increase in DNA content through endoreplication at stage 5. Knockdown of fizzy-related protein (Fzr), a key regulator of the mitosis-to-endocycle transition, disrupted the expression of cell cycle-related genes and caused a marked reduction in both binucleate FC numbers and DNA content, resulting in ovarian malformation and impaired egg development. Gene expression analyses revealed that Fzr knockdown caused aberrant expression and alternative splicing of genes related to spliceosome function and energy metabolism. Furthermore, these alterations appear to be at least partially independent of the polyploidization process. Our findings reveal a two-step polyploidization mechanism in BPH reproduction, offering insights into the evolutionary adaptation of reproductive strategies in insect pests. Additionally, this work advances our understanding of the molecular mechanisms underlying cell cycle transitions and establishes a foundation for future studies on insect reproduction and pest management strategies.

The predatory sting bug Arma custos and ectoparasitic mite Pyemotes zhonghuajia are important natural enemies which may co-occur in agroecosystems in China. Understanding interspecific interactions is essential for optimizing multi-agent biological control. This study presents the first systematic assessment of the compatibility and intraguild effects between these two species. Laboratory bioassays evaluated the impact of P. zhonghuajia density [0 (control), 1, 5, 10, 15, or 20 mites] on A. custos egg hatch rate and incubation period, and effect of mite density [0 (control), 1, 5, 10, 20, or 30 mites] on the paralysis and lethalityl of A. custos nymphs and adults. Results show that P. zhonghuajia did not significantly affect egg viability (82–86% hatch rate) and development (8.4–8.8 d), indicating baseline egg-stage compatibility. In contrast, nymphs and adults experienced strong mite density- and time-dependent paralysis and mortality. The young 1st–2nd-instar nymphs of A. custos were highly susceptible and completely paralyzed or died when they were exposed to 5–10 mites for 24 h; whereas older instars and adults exhibited higher tolerance, where high mortality occurred at higher mite densities of ≥ 20 individuals. This is the first study to estimate the critical density-dependent lethality: 5 mites for 1st–3rd instars, 10 mites for 4th–5th instars, and &gt; 10 mites for adults. These findings reveal a parasitism-mediated intraguild interaction, in which P. zhonghuajia dominated nymphal and adult stages of A. custos, while eggs remained largely unaffected. The results provide essential guidance for the future design of coordinated release strategies under field conditions, as they emphasize that temporal or spatial niche separation would be necessary to reduce direct suppression of A. custos and maintain the complementary pest control potential of both agents in applied settings. This study advances understanding of intraguild dynamics among natural enemies, offering practical and theoretical insights for multi-agent biodiversity-based pest management that require further field validation.

SUMMARYPhyscomitrium patens is a bryophyte model system particularly valuable for evolutionary developmental and comparative genomics studies. Sexual reproduction in bryophytes offers unique insights into the evolution of land plant reproduction. Unlike seed plants, bryophytes have a dominant gametophyte phase and provide significant advantages for studying sexual reproduction, such as the possibility to maintain embryo‐lethal mutants through vegetative propagation or the presence of motile male gametes. More than 25 years after the first publications of transcriptomic data for P. patens, expression data of most developmental stages of P. patens as well as its responses to various biotic and abiotic perturbations have been represented by microarrays or RNA‐seq datasets. To facilitate the use of such data, we introduce the MAdLandExpression atlas as a successor of PEATmoss (Physcomitrium Expression Atlas Tool), integrating its 109 P. patens expression experiments and expanding it with 20 recently published RNA‐seq samples of sexual reproduction stages, thus completing the coverage of the P. patens life cycle. The MAdLandExpression atlas also introduces new features for data visualization and analysis, such as the comparison of samples from multiple datasets and gene set normalization. Using this tool, the sexual reproduction dataset was analyzed, identifying genes potentially important for egg and sperm cell development, and confirming the behavior of known key genes in sexual development observed in previous studies.

RNA interference targeting tyrosine hydroxylase and dopa decarboxylase inhibits the reproduction and survival in the small brown planthopper Laodelphax striatellus: A promising strategy for pest control.