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The recent widespread mortality and tissue loss in Florida from stony coral tissue loss disease (SCTLD) has propelled the need for assisted reproduction to restore reefs, especially for the ESA listed species Orbicella faveolata. In situ gamete collection can be challenging due to the weather and resources (boats and divers) required during the expected spawning window. In the northern portion of the Florida coral reef tract, coral spawn collection has been even more difficult due to historical inconsistency in annual spawning times and the potential for “zombie” corals, i.e. large but reproductively senescent individuals. Therefore, we examined the current reproductive potential of seven large (>2 m diameter) O. faveolata colonies from this region, quantified their fecundity, and estimated the spawning timeframe using histology. Additionally, we explored whether previous SCTLD lesion amoxycillin treatments affected reproductive metrics. Understanding the reproductive capacity and spawning timing of these large corals, given their history of disease and disease treatment, is critical to evaluate potential impacts of SCTLD treatments and the success of assisted reproduction efforts. The histological analysis coupled with in-water observations indicated a probable split-spawn in these individuals in 2020, although the dates of spawning may not be consistent with predictions for the wider Caribbean or with other colonies in Miami and the Florida Keys. All seven large O. faveolata colonies were found to contain abundant oocytes, with no obvious impact of SCTLD treatments on gamete development or fecundity.

Abstract Studies on insecticide-induced stimulatory effects in pest insects have become of utmost importance due to their potential implications in pest management. Temperature influences the physiology and biology of ectothermic organisms like pest insects. It can also affect the toxicity and relative efficacy of insecticides that are used in agricultural fields. However, the impact of temperature on the insect stimulatory responses after exposure to mild insecticide-induced stresses has frequently been overlooked. Here, we investigated how different temperature levels (15; 20; 25; 28 °C) can modulate the toxicity of two synthetic insecticides chlorpyrifos (organophosphate) and deltamethrin pyrethroid); and subsequently how temperature impacts the survival and reproduction of the green peach aphid Myzus persicae exposed to sublethal concentrations of the two insecticides. Our findings indicated temperature-dependent effects of the two chemicals on mortality, longevity, and the number of nymphs produced by the aphids after lethal and sublethal exposures. In fact, besides the high toxicity induced by temperature at lower concentrations, the change’s magnitude and occurrence of stimulatory responses varied between temperatures and depended on the sublethal concentrations faced by the aphid females. Temperature increase from 15 to 28 °C increased chlorpyrifos and deltamethrin toxicity 4 and fivefold. Sublethal exposure of aphids extended the longevities for individuals treated with chlorpyrifos at 15 (all sublethal concentrations) and 25 °C (LC15 and LC20) and with deltamethrin at 20 (LC1) and 28 °C (LC20). Additionally, the total number of nymphs produced during the females' lifespan was increased after sublethal exposure to chlorpyrifos at 15 °C (LC1, LC5, and LC20) and at 20 °C (LC10) and to deltamethrin at 20 °C (LC1), 25 °C (LC5 and LC10) and 28 °C (LC1, LC5, and LC20). Our results reinforce the importance of a shift from studies focusing on the stimulatory effects of single stresses to studies investigating the effects of stressors’ combinations on insect hormetic response.

Abstract Background Although many countries have shown interest in eliminating malaria, approaches that complement existing vector control interventions are needed because existing methods have been scaled up but malaria still persists. Therefore, the effect of ivermectin administration to cattle was evaluated for its effect on mortality, survivorship and mortality of laboratory reared Anopheles arabiensis. Methods Three calves were randomly selected and injected with ivermectin at a therapeutic dose of 0.2 mg/kg, while the other two calves received no treatment and served as controls. Five tents were constructed for the trial. Calves were housed in tents (one per tent) and then 30 starved female An. arabiensis were introduced into each tent. Only fully engorged females were collected from each tent and placed in different mosquito cages to monitor their mortality, survival and fecundity. Data analysis was done using SPSS version 16. Results During the follow-up period (until day 21), ivermectin induced significantly higher mortality when compared to controls. It resulted in an average 24-h mortality rate of 81.6% against An. arabiensis on the first day following treatment. 100% An. arabiensis that fed on ivermectin-treated calves on the first day after treatment died within four days. Egg production rate of An. arabiensis that fed on ivermectin-treated calves was significantly lower compared to controls (F = 768.7, P

Brown planthopper (BPH), Nilaparvata lugens Stål, is a significant pest widely recognised for its detrimental impact on rice production. Biological agents, such as the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill., can effectively control this pest. B. bassiana, known for its endophytic abilities, colonises various plant tissues. This research aims to assess B. bassiana’s colonosation capacity on rice plants and its impact on nymph mortality and BPH fecundity. Four isolates of B. bassiana (BbWS, Pb211, Td312, and BbJg) were used, each with conidial density of 108 conidia/ml. The application menthod involved soaking rice seeds in the fungus for 24 hours. The results showed that all B. bassiana isolates could successfully establish as endophytes within rice plants, colonising all tissue parts, with leaves exhibiting the highest fungal colonisation at 58%. Seed soaking with B. bassiana reduced eggs hatching by 23.88% and increased nymph mortality by 40%. The presence of B. bassiana in rice tissue also influenced BPH adults fecundity. Notably, the BbWS isolate demonstrated the most significant effectiveness in elevating nymph mortality and reducing BPH fecundity.

In this study, some biological characteristics of the invasive moon crab, Matuta victor, which has recently entered the waters of the northeastern Mediterranean, Türkiye, were investigated for the first time. The study was carried out seasonally on sandy bottoms at 0.5-3 m depths along Karataş (Adana, Türkiye) coasts between 2020 -2021. A total of 364 crabs were obtained, 93 females (27 ovigerous), 270 males and one juvenile. The carapace width of female crabs ranged between 27.49-49.30 mm with a mean of 41.55±4.01 mm. The carapace width of male crabs ranged between 21.28-66.70 mm with a mean of 49.15±8.97 mm. Mean carapace length measurements in females and males were 26.83±2.52 mm and 32.71±5.85 mm, and the mean total weights were 8.18±1.99 g and 16.27±7.30 g, respectively. The male:female ratio was 2.16:1. Morphometric relationships indicated negative allometric growth for females, males, and both sexes. Ovigerous females were obtained in all seasons except the winter. The female crabs with carapace widths that ranged between 35.31-48.84 mm and a mean of 41.97±3.29 mm had a mean fecundity of 36822.04±29745.9 eggs.

Absolute fecundity of chum salmon Oncorhynchus keta is investigated for the commercial herd dwelled at Iturup Island. Currently, the herd is formed mostly by fish of hatchery origin but has retained the same species and regional features that distinguished it when it was formed mainly due to natural spawning. The value of absolute fecundity is determined for 3833 females and ranges from 769 to 4400 oocytes. For the fish of two dominant age groups (3+ and 4+), this number usually decreases with age, with the exception of particularly large older fish with greater fecundity. Same factors that promote abundance of hatchery fish in the herd also contribute to decreasing of abortive processes in the ovaries, therefore the absolute fecundity correlates closely and positively with the catch of chum salmon in the coastal waters.

All available information on gametogenesis of chum salmon Oncorhynchus keta cited in scientific literature is summarized. The phases of indifferent development and sex differentiation are overviewed, specific features of the testes and ovaries development are noted, forming of fecundity is analyzed.

Apigenin is an organic flavonoid abundant in some plants such as parsley, chamomile, or celery. Recently, it has been investigated for several of its pharmacological characteristics, such as its ability to act as an antioxidant, reduce inflammation, and inhibit the growth of cancer cells. The purpose of this review is to provide a summary of the existing knowledge regarding the effects of apigenin on female reproductive systems and its dysfunctions. Apigenin can influence reproductive processes by regulating multiple biological events, including oxidative processes, cell proliferation, apoptosis, cell renewal and viability, ovarian blood supply, and the release of reproductive hormones. It could stimulate ovarian folliculogenesis, as well as ovarian and embryonal cell proliferation and viability, which can lead to an increase in fertility and influence the release of reproductive hormones, which may exert its effects on female reproductive health. Furthermore, apigenin could inhibit the activities of ovarian cancer cells and alleviate the pathological changes in the female reproductive system caused by environmental pollutants, harmful medications, cancer, polycystic ovarian syndrome, ischemia, as well as endometriosis. Therefore, apigenin may have potential as a biostimulator for female reproductive processes and as a therapeutic agent for certain reproductive diseases.

Few investigations have been made to determine whether pharmaceutical drugs cause any generational effects. These effects can be divided into intergenerational and transgenerational effects. In insects, the F1 offspring of exposed individuals are considered to show intergenerational effects (as they have been exposed as germ cells or early embryos), while the F2 generation is fully non-exposed and considered to show transgenerational effects. Here, the common over-the-counter (OTC) drug, paracetamol, is investigated for genotype-specific responses and effects across generations on three life-history traits: fecundity, longevity, and spontaneous locomotor activity levels in the model species Drosophila melanogaster. Seven isofemale D. melanogaster lines were exposed to a high and intermediate dose of paracetamol determined by a dose–response curve. NMR investigations verified the long-term presence of paracetamol in the food substrate. Phenotypic effects of paracetamol ingestion were investigated on flies exposed to the drug and in their offspring and grand-offspring. The dose–response curve indicated genotype-specific responses to paracetamol. In the following experiment, all traits investigated displayed significant effects of paracetamol ingestion for at least one of the seven isofemale lines, and we detected strong genotype-specific responses to paracetamol. Fecundity tended to increase in individuals directly exposed to the drug whereas fecundity in the F2 generation was reduced (transgenerational). Longevity generally decreased in directly exposed individuals but tended to increase in F1 offspring (intergenerational). Paracetamol effects on spontaneous locomotor activity were primarily detected as transgenerational effects and were rarely seen in directly exposed individuals. However, across lines, no clear overall trend could be determined for any trait. The generational effects and marked genotype-specific response to paracetamol warrants further investigation of both genotype-specific responses and generational effects in general.

More than 40 species of lampreys (Petromyzontiformes) are known worldwide. Some of them are parasitic and feed on the blood of fish or other aquatic animals. Lampreys spawn once in their lifetime, after which they die. One of the representatives of the ichthyofauna of European rivers is the river lamprey, Lampetra fluviatilis. The river lamprey is now an endangered species due to loss and degradation of their habitats. The present study investigated gonadal development without hormonal stimulation in female river lampreys during puberty under controlled conditions for a period of seven months. Female river lampreys were kept in conditions that mimicked the natural environment. During the November–May period, samples were taken monthly to determine the extent of gonadal development and gastrointestinal and liver changes using histological examination. From the results obtained, the dynamical changes were determined for the following: gonadosomatic index (GSI; %), hepatosomatic index (his; %), and digestivesomatic index (DSI; %). With the gonadal development of female lampreys, an increase in GSI (7–23%; November–May) and a decrease in DSI (0.4–0.1%; November–May) histological changes were observed in the gonads (oocyte development), intestines (over time, decreased lipid vacuoles and enterocyte apoptosis), and in the liver (decreased lipid vacuoles and hepatocyte apoptosis over time) and in the digestive system resulting from its degradation. Also, it was observed that there was a change in the color of the liver to green in April. This study demonstrated the key role of the liver in the oocyte maturation process in this species.

Abstract Background MicroRNAs (miRNAs) play an important regulatory role in mammalian reproduction. Currently, most studies are primarily concentrated on ovarian miRNAs, ignoring the influence of endometrial miRNAs on the fecundity of female sheep. To uncover potential regulators of sheep fecundity, RNA-seq was used to comparatively analyze miRNA expression profiles of endometrium between high prolificacy sheep (HP, litter size = 3) and low prolificacy sheep (LP, litter size = 1) with FecB genotype. Results Firstly, genomic features of miRNAs from endometrium were analyzed. Furthermore, 58 differentially expressed (DE) miRNAs were found in the endometrium of Hu sheep with different litter size. A co-expression network of DE miRNAs and target genes has been constructed, and hub genes related litter size are included, such as DE miRNA unconservative_NC_019472.2_1229533 and unconservative_NC_019481.2_1637827 target to estrogen receptor α (ESR1) and unconservative_NC_019481.2_1637827 targets to transcription factor 7 (TCF7). Moreover, functional annotation analysis showed that the target genes (NRCAM and NEGR1) of the DE miRNAs were significantly enriched in cell adhesion molecules (CAMs) signaling pathway, which was related to uterine receptivity. Conclusion Taken together, this study provides a new valuable resource for understanding the molecular mechanisms underlying Hu sheep prolificacy.

Abstract Background Mosquito-borne diseases exert a huge impact on both animal and human populations, posing substantial health risks. The behavioural and fitness traits of mosquitoes, such as locomotion and fecundity, are crucial factors that influence the spread of diseases. In existing egg-counting tools, each image requires separate processing with adjustments to various parameters such as intensity threshold and egg area size. Furthermore, accuracy decreases significantly when dealing with clustered or overlapping eggs. To overcome these issues, we have developed EggCountAI, a Mask Region-based Convolutional Neural Network (RCNN)-based free automatic egg-counting tool for Aedes aegypti mosquitoes. Methods The study design involves developing EggCountAI for counting mosquito eggs and comparing its performance with two commonly employed tools—ICount and MECVision—using 10 microscopic and 10 macroscopic images of eggs laid by females on a paper strip. The results were validated through manual egg counting on the strips using ImageJ software. Two different models were trained on macroscopic and microscopic images to enhance egg detection accuracy, achieving mean average precision, mean average recall, and F1-scores of 0.92, 0.90, and 0.91 for the microscopic model, and 0.91, 0.90, and 0.90 for the macroscopic model, respectively. EggCountAI automatically counts eggs in a folder containing egg strip images, offering adaptable filtration for handling impurities of varying sizes. Results The results obtained from EggCountAI highlight its remarkable performance, achieving overall accuracy of 98.88% for micro images and 96.06% for macro images. EggCountAI significantly outperformed ICount and MECVision, with ICount achieving 81.71% accuracy for micro images and 82.22% for macro images, while MECVision achieved 68.01% accuracy for micro images and 51.71% for macro images. EggCountAI also excelled in other statistical parameters, with mean absolute error of 1.90 eggs for micro, 74.30 eggs for macro, and a strong correlation and R-squared value (0.99) for both micro and macro. The superior performance of EggCountAI was most evident when handling overlapping or clustered eggs. Conclusion Accurate detection and counting of mosquito eggs enables the identification of preferred egg-laying sites and facilitates optimal placement of oviposition traps, enhancing targeted vector control efforts and disease transmission prevention. In future research, the tool holds the potential to extend its application to monitor mosquito feeding preferences. Graphical Abstract

Cited information on gametogenesis of pink salmon Oncorhynchus gorbuscha Walbaum is summarized. Periods of indifferent development and sex differentiation are considered, development of the testes and ovaries is traced, and the fertility formation is analyzed. Regularities of sex reversion, unique for salmonids, and evolutionarily acquired specific features of oogenesis associated with a short life cycle are noted.

Investigations of development of Microdeutopus gryllotalpa under conditions of the fouling community in Odessa Bay, Black Sea were carried out for two years from January 2013 to December 2014. Monthly samples were taken from the underwater surface of solid substrates located in the coastal zone of the Odessa Bay. In addition to quantitative parameters of these invertebrates, the characteristics of their reproduction, absolute fecundity, the total number of egg-laying during the life cycle, as well as the relationship between their body size, weight, and fecundity parameters were studied. The reproductive process of these crustaceans proceeded throughout the year, but its intensity increased synchronously with the increase the quantitative parameters of invertebrates in spring and autumn during periods of sharp changes in sea water temperature. The maximum absolute fecundity of female 8 mm in size was 64 eggs. The relationship between the wetweight and body length of oviparous females is isometric. The parameter of absolute fecundity is directly proportional to the body weight of the female. Under the conditions of the fouling community in the Odessa Bay, the female M. gryllotalpa can produce about 7 egg-laying during her life cycle.

The northern bald ibis Geronticus eremita disappeared from Europe in the Middle Ages. Since 2003 a migratory population has been reintroduced in Central Europe. We conducted demographic analyses of the survival and reproduction of 384 northern bald ibises over a period of 12 years (2008–2019). These data also formed the basis for a population viability analysis simulating the possible future development of the northern bald ibis population under different scenarios. We analysed life stage-specific survival rates, rearing protocols and colonies, and the influence of stochastic catastrophic events and reinforcement translocations on population growth. Life stage-specific survival probabilities were 0.64–0.78. Forty-five per cent of the mature females reproduced, with a mean fecundity of 2.15 fledglings per nest. The complementary population viability analysis indicated that the Waldrappteam population is close to self-sustainability, with an estimated population growth rate of 0.95 and a 24% extinction probability within 50 years. Of the 326 future scenarios tested, 94% reached the criteria of extinction probabilities < 5% and population growth rates > 1. Stochastic catastrophic events had only a limited effect. Despite comparatively high survival and fecundity rates the population viability analysis indicated that to achieve self-sustainability the Waldrappteam population needs further translocations to support population growth and the implementation of effective measures against major mortality threats: illegal hunting in Italy and electrocution on unsecured power poles. The findings of this study are to be implemented as part of a second European LIFE project.

Objective: To determine if an association exists between body mass index (BMI) and fecundity after intrauterine insemination (IUI). Design: Retrospective cohort study. Setting: Academic-based fertility clinic. Patient(s): Patients undergoing IUI July 2007 to May 2012. Intervention(s): None. Main Outcome Measure(s): Primary outcome: live-birth rate (LBR) per IUI cycle; secondary outcomes: positive pregnancy test and clinical pregnancy rates (CPRs). Result(s): A total of 1959 cycles were performed on 661 women (mean age, 31.9 ± 4.9 years). When examined by obesity class, LBR and CPR were similar for women with class I, II, and III obesity when compared with women with normal BMI. However, class III obese women (adjusted risk ratio [aRR], 1.70; 95% confidence interval [CI], 1.12–2.59) had increased pregnancy rates compared with normal BMI, but no differences in pregnancy rates were observed for women with class I or II obesity. In addition, pregnancy rates (aRR, 1.50; 95% CI, 1.12–2.02) and CPR (aRR, 1.51; 95% CI, 1.07–2.14) were higher in overweight women relative to normal BMI. Notably, among patients with ovulatory dysfunction, CPRs after IUI were reduced by 43% in obese women (aRR, 0.57; 95% CI, 0.37–1.07), whereas women without ovulatory dysfunction were twice as likely to achieve a clinical pregnancy when they were obese (aRR, 1.96; 95% CI, 1.19–3.24). The CIs for the obesity risk ratios in each stratum of ovulatory function exhibited no overlap, suggesting evidence of potential effect modification by ovulatory function. Conclusion(s): LBRs after IUI were similar across BMI subgroups. This is in contrast to research of in vitro fertilization treatments showing lower LBR with increasing BMI. However, obesity may adversely affect IUI CPR in those with ovulatory dysfunction in particular. The reason for this discrepancy is unclear and warrants further study.

Abstract This study investigated the reproductive traits of the hermaphroditic four-finger threadfin, Eleutheronema tetradactylum, along the coasts of Thailand during January to December 2021. Fish samples were collected from Pattani Bay, Thailand to assess the sex ratio, gonadosomatic index (GSI), maturity stage and fecundity. Additional fish samples were also collected from other areas to evaluate the length and weight at first sex change (Ls50 and Ws50) and length at first maturity (Lm50). The overall sex ratio for male and female was 1:0.69 with male being predominant throughout the year. Threadfin fish spawn the whole year round with peaks during moderate rainy and heavy rainy seasons. Histological examination confirmed its protandrous hermaphrodite posing multiple spawning habits. The average fecundity was 1.85 × 105 ± 1.05 × 105 eggs and positively related with standard length, body weight, gonad weight, and egg diameter (p

The tomato leaf miner, Tuta absoluta (Meyrick) is one of the most destructive pests of tomato in field and greenhouses. Llife history and population growth of this pest were investigated on three solanaceous plants including four varieties of tomato (Western Red, Matin, Serin, and Rio-Grand), three varieties of eggplant (White-Casper, Ravia, and Pearl-Ground) and three varieties of sweet pepper (Bachata, Lorca, and Nirvin). The developmental time, survival, longevity, and fecundity of the pest on the leaves of tested varieties were investigated. The experiments were conducted at 25 ± 2°C, relative humidity of 65 ± 5% and a photoperiod of 16:8 (L: D) h. The results of the statistical comparison of the varieties within each host plant showed that life table parameters of the insect were not significantly different on tomato varieties and on eggplant varieties. However, among pepper varieties, the net reproductive rate, intrinsic rate of increase, and finite rate of increase rate on variey Lorca were higher than on Nervin and Bachata. The results of comparison among varieties of different hosts showed that the highest immature survival was observed on tomato, varieties Serin and Matin, and the lowest survival was seen on pepper, varieties Lorca and Nirvin. The longest developmental time was obtained on pepper, varieties Bachata and Nirvin. The lowest fecundity and the shortest oviposition period were found on pepper, varieties Bachata and Nirvin. The net reproductive rate, intrinsic rate of increase, and finite rate of increase were lowest on pepper, varieties Bachata and Nirvin, and other varieties showed no significant differences. In general, tomato varieties were susceptible,, and eggplant variety White-Casper and pepper varieties Bachata and Nirvin were partially resistant against T. absoluta. This information provides the possibility of using these varieties in order to manage T. absoluta populations during its outbreak.

Poaching is a global issue that threatens many species. However, little research attention has been paid to key life history traits that might help offset some of the worst genetic and demographic impacts of poaching. We investigate the onset of flowering and fecundity in Aquilaria sinensis, an agarwood-producing tree species that faces a constant threat of poaching throughout its native range in southern China. We hypothesise that certain life history traits in this species could buffer genetic erosion associated with selective poaching of larger individuals. We genotyped 1464 individuals using 15 microsatellite markers and examined the difference in genetic diversity between seedlings and adults, as well as that between individuals either side of the threshold diameter at breast height (DBH) size class targeted by poachers. Our study reveals that flowering commences at a DBH of 2.50 cm and that even trees at a DBH of about 6.9 cm invest heavily in seed-set, but that poachers tend to target individuals with a DBH of 15.25 cm or greater. No significant difference in genetic diversity was detected among individuals belonging to seedling and adult life-history stages, or between targeted and non-targeted size classes. The lack of such difference could be explained by certain life history traits which offset some of the most adverse impacts of poaching in Aquilaria sinensis, with important implications for the management and conservation of other species that are threatened by poaching.

The inactive ovaries of cattle caused a significant economic loss, so the current study is intended to recover and enhance the fertility of dairy cattle suffering from anestrus by kisspeptin-10. Forty Holstein Friesian cows, aged 3.5-6.8 years with inactive ovaries for 60-70 days of postpartum, were distributed randomly into four equal groups. The control (C) group administered 5 mL intramuscularly (I.M) of normal saline, Gn group administered 0.5 mg/animal I.M of GnRH. K1 and K2 were administered with 6 μg/kg BW I.M and 12 μg/kg BW I.M of kisspeptin-10, respectively. After heat signs were detected, artificial insemination was performed. Blood samples were collected at 0, 2, 6, 24, and 72 hours post-hormonal injection to estimate fertility hormones, and fecundity features were demonstrated after hormonal treatment and after twelve months. The current results noted a significant (p

Background The present study investigated the population structure and breeding biology of the burrowing brachyuran crab species Dotilla blanfordi Alcock, 1900, which is commonly found on the sandy beach of Bhavnagar, located on the Gulf of Kachchh, Gujarat coast, India. Methods Monthly sampling was conducted from February 2021 to January 2022 at the time of low tide using three line transects perpendicular to the water line, intercepted by a quadrate (0.25 m2) each at three different levels of the middle intertidal region: 20 m, 70 m, and 120 m. The quadrate area was excavated up to 30 cm and sieved for specimen collection. The collected specimens were categorised into different sexes viz., male, non-ovigerous female, or ovigerous female. For the fecundity study of D. blanfordi, the carapace width (mm) as a measure of size as well as their wet weight (g), size, number, and mass of their eggs were also recorded. Results The study revealed sexual dimorphism among the population, with females having significantly smaller sizes as compared to males. The overall population was skewed towards females, with a bimodal distribution of males and females. The occurrence of ovigerous females throughout the year suggests that the population breeds incessantly throughout the year, with the highest occurrence in August and September. A positive correlation was observed between the morphology of crabs (carapace width and wet body weight) and the size, number, and mass of eggs.

A laboratory experiment was conducted to study the biology of pink bollworm Pectinophora gossypiella (Saunders) on cotton at four different temperature levels. It was found that males have a considerably shorter total life cycle duration on cotton at 35±1°C (29.5 days) followed by 30±1°C (37.2 days), 25±1°C (46.9 days) and highest at 20±1°C (50.8 days). Similarly, minimum total life cycle duration of female P. gossypiella was recorded at 35±1°C (30.2 days) followed by 30±1°C (38.0 days), 25±1°C (47.3 days) and maximum at 20±1°C (51.7 days). The highest fecundity was observed at 30±1°C (106.2) followed by 25±1°C (100.1), 35±1°C (60.1) and lowest at 20±1°C (55.2). Male as to female sex ratio was highest at 35±1°C (1:1.5) followed by 25±1°C (1:1.4), 30±1°C (1:1.3) and lowest at 20±1°C (1:1.2). These findings revealed that variation in temperature significantly influences the life cycle duration, fecundity and sex ratio of pink bollworms on cotton, with higher temperatures accelerating development and enhancing reproductive success.

Broodstock nutrition is the most essential constituent of sustainable aquaculture production. Its impact on the reproductive performance and profitability of commercial aquaculture has been the subject of considerable research. The present paper reviews the literature available on the subject, examining the implication of Nile tilapia broodstock nutrition on parameters including maturation, fecundity, fertilization, embryo development, larval quality, and survival rate. The provision of a nutritive diet composed of essential macro- and micronutrients including proteins, lipids, carbohydrates, vitamins, minerals, and functional additives, such as prebiotics, enzymes, hormones, and probiotics, in different proportions is discussed. Special emphasis is given to literature dealing with the effects of dietary protein and lipid on vitellogenesis and ovarian maturation, fecundity, egg hatching rate, larval quality, and fry survival number. The impact of the feeding regime on reproductive performance is described.

Abstract Rainbow trout (Oncorhynchus mykiss) is among the most widely translocated fish species in the world. The current study evaluated the spawning interactions between naturalized and wild rainbow trout from two high‐altitude second‐order streams, in Kenya. Data on total length, weight, condition factor, fecundity, fertilization, egg diameter and fry survival were collected on spawning rainbow trout between March and December 2021. Length–weight relationship showed parabolic equations as W = 0.0144L2.900, W = 0.0069L3.0285 and W = 0.00027L3.175 for wild fish stock, hatchery‐reared and wild × hatchery‐reared rainbow trout, respectively. Total fecundity differed significantly among the hatchery‐reared, wild fish and the cross of the two (p

Abstract The Squaretail mullet, Ellochelon vaigiensis, is a commercial fish species distributed throughout the Indo‐Pacific region. This species tolerates wide variations in salinity, having been reported from both freshwater and marine habitats. Although economically significant, there is little information on its reproduction, especially in the Vietnamese Mekong Delta (VMD), where it is heavily extracted. Our study elucidates the breeding pattern, seasonality, first length at maturity, as well as potential and relative fecundity of this species. Fish specimens were collected by trawl nets from November 2020 to October 2021 at four estuarine sites within the VMD. We found this species to be a synchronous spawner, with peaks in reproductive activity from June to September. In the populations we surveyed, there was significant dominance of males (1.26:1.00) based on 942 fish samples (526 males and 416 females). The length at 50% maturity for females was significantly higher than for males at all sites and ranged from 10.6 to 19.3 cm. The diameter of the eggs examined for this species exhibited slight variation, from 0.43 to 0.54 mm. The potential fecundity ranged from 246,254 ± 35,878 to 411,970 ± 54,370 eggs, corresponding to female length and weight of 26.7–32.6 cm and 102.97–234.19 g, respectively. Relative fecundity values were highest at Thanh Phu, Ben Tre (6388 ± 605 eggs), and Dong Hai, Bac Lieu (6461 ± 637 eggs), followed by Tran De, Soc Trang (4729 ± 408), and were found to be lowest at Duyen Hai, Tra Vinh (3117 ± 223 eggs). Information on reproductive behavior in this species has far‐reaching impacts on sustainable extractions, stock conservation, and aquaculture.

Simple Summary: Galaxias maculatus plays an important ecological and socioeconomic role in Chile. We determine the sex ratio, sexual maturity stages, gonadosomatic index, spawning period, type and frequency of spawning, and fecundity under experimental culture. The sex ratio was close to 1:1. First sexual maturity was reached at one year of age in 50% of the population. The highest GSI in both females and males was found in August. Nevertheless, females have a long spawning period, divided into two subperiods; the highest reproductive peak occurs between September and October, and the minor peak occurs between December and February. The females spawned between 3 and 10 times over a period of two months. The number of embryos per female per day varied from 1 to 429, while the total number of embryos per female during the entire season varied from 163 to 1044. This knowledge will be useful to establish future reproductive programs in captivity as a strategy for sustainable fishery and aquaculture management. This study determines the reproductive patterns of puye (Galaxias maculatus) under culture conditions. A population of 567 wild fish was caught in the Cautín River, Chile, and held in captivity for four years. Mortality, sex ratio, gonadosomatic index (GSI), sexual maturity stages, spawning period, type and frequency of spawning, and fecundity were measured. The fish grew throughout the experimental period, with the fastest rate during the first half of the first year of life. The highest mortality occurred during the first three months of the experiment and during the spawning season. The sex ratio was almost 1:1 (female:male). First sexual maturity was reached at one year of age, with an average weight of 0.85 ± 0.01 g, total length of 4.85 ± 0.16 cm, and condition factor 0.0074. The highest GSI in both females (12.14 ± 0.74) and males (17.7 ± 2.70) was recorded in August. Nevertheless, the females spawned 3 to 10 times between September and February, with the highest reproductive peak between September and October. The number of embryos per female per day varied from 1 to 429, while the total number of embryos per female during the entire season evaluated varied from 163 to 1044. There was a high correlation (r = 0.82) between absolute fecundity and body weight. Although further studies are needed in this field, these results are basic for establishing future reproductive programs in captivity as a strategy for sustainable fisheries and aquaculture management. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigates the expression characteristics of circRNAs during follicular development in sheep with the FecB gene mutation through the use of RNA sequencing. A total of 38,979 circRNAs were identified, and differential expression was observed between different genotypes and developmental stages. Functional enrichment analysis revealed that these differentially expressed circRNAs are associated with signaling pathways such as MAPK, gap junctions, and progesterone-mediated oocyte maturation. This study also predicted a competitive endogenous RNA network, suggesting that specific circRNAs may be involved in regulating LH synthesis and secretion, thereby influencing the process of ovulation. These findings provide important insights into the role of circRNAs in follicular development and ovulation in the sheep hypothalamus and have practical implications for the improvement of sheep breeding practices. Circular RNAs (circRNAs) are a specific type of noncoding RNA, and some have defined roles in cellular and biological processes. However, little is known about the role of circRNAs in follicular development in sheep with FecB (fecundity Booroola) mutations. Here, the expression profiles of circRNAs were investigated using RNA sequencing (RNA-seq) in the follicular phase (F) and the luteal phase (L) of FecB mutant homozygous (BB) and wild-type (WW) Small Tail Han sheep. A total of 38,979 circRNAs were identified, and 314, 343, 336, and 296 of them were differentially expressed (DE) between BB_F and BB_L, WW_F and WW_L, BB_F and WW_F, and BB_L and WW_L, respectively. The length, type, and chromosome distribution of the circRNAs and the expression characteristic between the circRNAs and their host genes in the sheep hypothalamus were ascertained. Enrichment analysis showed that the host genes of DE circRNAs in the follicular and luteal phases were annotated to MAPK, gap junctions, progesterone-mediated oocyte maturation, oocyte meiosis, and other hormone-related signaling pathways, and the different FecB genotypes were annotated to the gap junctions, circadian entrainment, MAPK, and other hormone-related signaling pathways. The competing endogenous RNA network prediction revealed that the 129 target miRNAs might be bound to 336 DE circRNAs. oar_circ_0000523 and oar_circ_0028984, which were specifically expressed during the follicular phase in the BB genotype sheep, probably acted as miRNA sponges involved in the regulation of LH synthesis and secretion. This study reveals the expression profiles and characterization of circRNAs at two phases of follicular development considering different FecB genotypes, thereby providing an improved understanding of the roles of circRNAs in the sheep hypothalamus and their involvement in follicular development and ovulation. [ABSTRACT FROM AUTHOR]

Panonychus citri is a worldwide citrus pest that is currently controlled through the use of insecticides. However, alternative strategies are required to manage P. citri. Recent studies suggest that the ATP-binding cassette (ABC) transporter G subfamily plays a crucial role in transporting cuticular lipids, which are essential for the insect's barrier function against microbial penetration. Therefore, investigating the potential of the ABC transporter G subfamily as a control measure for P. citri could be a promising approach. Based on the genome database, the gene was cloned, and the transcriptional response of ABCG23 for the different developmental stages of P. citri and under spirobudiclofen stress was investigated. Our results showed that the expression level of ABCG23 was significantly lower in adult females exposed to treatment compared to the control and was higher in females than males. The knockdown of ABCG23 using RNAi led to a decrease in the survival rate, fecundity, and TG contents of P. citri. Additionally, a lethal phenotype was characterized by body wrinkling and darkening. These results indicate that ABCG23 may be involved in cuticular lipid transportation and have adverse effects on the development and reproduction of P. citri, providing insight into the discovery of new targets for pest management based on the insect cuticle's penetration barrier function. [ABSTRACT FROM AUTHOR]

The three major macronutrients – proteins (P), carbohydrates (C), and lipids (L) – constitute the fundamental nutrient niche. In order to meet their nutritional requirements, organisms need to assess their nutritional state, select suitable foods, and regulate the amount of food eaten. The objective of this study was to determine whether larval nutrition could have a differential effect on female and male survival and fecundity by manipulating the P:C:L ratios in diet environments. We manipulated food availability during the larval stages, subjecting the larvae to food regimes with different P:C:L ratios. Upon adult emergence, we examined the fecundity, fertility, survival, and longevity of the various larval nutrition treatments. We then assessed the reproductive performance (fecundity and egg hatching) under an ad libitum food regime. We found that the concentration of macronutrients in the larval hemolymph indicates that the P:C:L ratio in the larval diet affects the assignment of macronutrients, and this effect is carried over to males and females differently. A larval diet with high carbohydrate content affects the carryover of macronutrients and male and female fitness. According to the life‐history traits, an adult that emerged from a larva with high lipid content in the hemolymph could suggest better health status. Insects with high cold tolerance have high body lipids content. Interactions between lipids, carbohydrates, and proteins suggest that their relative ratios must be taken into consideration in the design and improvement of artificial diets. [ABSTRACT FROM AUTHOR]

This study was the first to investigate the key reproductive traits of the electric lantern fish Electrona risso (Myctophidae, n = 918) and the bigscale fishes (Melamphaidae) Melamphaes polylepis (n = 260) and Scopelogadus mizolepis (n = 649). Specimens of these mesopelagic species were collected in March and April 2015 in the eastern Central Atlantic (0–24° N, 20–26° W). Sex ratio was not significantly different from 1:1 in E. risso and M. polylepis but significantly skewed toward female dominance in S. mizolepis. Reproductive phases were determined macroscopically and by histological analyses on selected individuals. Female length at 50% maturity (L50) was 55.1 mm standard length (LS) in E. risso, with an observed female maximum length (Lmax) of 81.2 mm LS. M. polylepis females had an L50 of 40.2 mm LS and an Lmax of 86.7 mm LS. S. mizolepis had an L50 of 46 mm LS and an Lmax of 97.9 mm LS. The three species show histological features of iteroparity, but the E. risso population appears to occur in two year‐classes and experience only one spawning season per lifetime in the study region. All three species are batch‐spawners. A batch fecundity of 2668 eggs was estimated from one E. risso individual, with a relative batch fecundity of 369 eggs g−1 gonad‐free body mass. M. polylepis had a batch fecundity of 1027 eggs and a relative batch fecundity of 149 eggs g−1 (n = 3). S. polylepis had a batch fecundity of 1545 eggs and a relative batch fecundity of 215 eggs g−1 (n = 21). The median gonado‐somatic index during the actively spawning phase of E. risso was 4.5, significantly lower than that of M. polylepis (7.5) and S. mizolepis (7.1). No regressing or regenerating phases were observed in this study. Batch‐spawning in all three species is suggested to be advantageous to cope with intra‐annual variability in food supply and other risks for offspring survival. With what appears to be in effect a (facultative) semelparous strategy in combination with a short life span in E. risso, interannual differences would have a great effect on population dynamics of this species. Knowledge is still lacking on temporal aspects of reproduction such as the duration of the spawning season and the frequency of spawning, as well as age and growth. [ABSTRACT FROM AUTHOR]

Extreme heat events lower the fitness of organisms by inducing physiological stress and increasing metabolic costs. Yet, little is known about the role of life‐history traits in elucidating population responses to extreme heat events. Here, we used a trait‐based approach to understand population resistance and recovery using four closely related species of soil‐dwelling Collembola. We measured thermal reaction norms of life‐history traits (survival and reproductive traits) and used this information to identify ecological mechanisms linked to population responses after an extreme heat event (i.e. one week at 26–30°C, representing + 10°C above ambient conditions). Furthermore, we investigated potential shifts in the body size distribution of recovering populations to better understand if extreme heat events can restructure body size spectra within populations. While resistance remained unaltered across species in our study, the recovery response of the most heat‐sensitive species (Protaphorura pseudovanderdrifti, predominantly a boreal species) was strongly affected by the extreme heat event (−54% population change compared to ambient conditions). Given that the fecundity (linked to recovery) of P. pseudovanderdrifti was more sensitive to heat than their survival (linked to resistance), we detected a decoupling between population resistance and recovery to an extreme heat event in this species. In addition, the detrimental effects of heat on fecundity were largely responsible for a drop in the proportion of small‐sized (juvenile) individuals in the recovering populations of P. pseudovanderdrifti. Thermally insensitive resistance and recovery in the other three species (P. armata, P. fimata, P. tricampata; predominantly temperate species) can be explained by their high survival and fecundity at warmer temperatures. We highlight that life‐history trait responses to warming can help explain population resistance and recovery after extreme heat events. [ABSTRACT FROM AUTHOR]

Context. Reproductive efficiency in ewes can vary widely depending on their fertility (pregnancy rate) and fecundity (litter size) and on their ability to rear multiple litters. Litter size and sex are important factors that contribute to lamb mortality, and hence reproductive efficiency. However, little is known about their interaction when fetuses of either sex grow in utero as co-twins, nor the impact that this interaction has on subsequent performance in domestic flocks. Aims and methods. We examined the effect of type of birth (single, twin) and of sex of co-twin (F, F[F], F[M], M, M[M], M[F] where the symbol within brackets indicates sex of co-twin) on birth weight, survival to weaning, weaning and hogget liveweights and scrotal circumference. In addition, reproductive performance (fertility, fecundity, lamb survival, weaning rate) of female progeny was examined as well as the performance of their lambs (birth and weaning weight). This large-scale study (>13 000 lambing observations) was conducted with Australian Merino sheep from four studs, mated over nine annual cycles. Key results. Sex of co-twin had no effect on birth weight and on later stages of growth. Sex of co-twin altered survival, with fewer of the M[M] class surviving to weaning compared with other co-twin classes (P < 0.05). Scrotal circumference did not vary between the male classes. Although reproductive performance (fecundity, lamb survival, weaning rate) was greater in ewes twin to a male (F[M]) than in single females (F) (P < 0.05), this difference could be due to greater geneticmerit of twin versus single-born progeny. Conclusions. Reproductive performance of females with a male co-twin exceeded that of single females; the difference could be due to greater genetic merit of twin-born ewes rather than a direct effect of in utero environment. There was no difference between females with a male co-twin and females with a co-twin of the same sex. Reproductive capacity of males was not affected by co-twin class or type of birth. Implications. These results suggest that an increase in twinning rate by managerial or genetic means will not result in undesirable side effects due to sex of co-twin in utero. [ABSTRACT FROM AUTHOR]

Hydrothermal vents host fragmented habitats and are increasingly becoming the target of deep-sea mining projects for their mineral resources. Managing a future sustainable exploitation requires a good understanding of the resilience of biological populations to natural and anthropogenic disturbances, hence a better knowledge of species life history traits and their capacity to replenish local populations or colonise distant sites. In this context, we studied the reproductive biology and recruitment patterns of three main representative hydrothermal vent limpets of the South West Pacific back-arc basins, Lepetodrilus schrolli, Lepetodrilus fijiensis and Shinkailepas tollmanni, in relation to habitats and environmental conditions. Limpets were collected in Bathymodiolus and Ifremeria nautilei habitats at several vent sites in the Manus, North Fiji and Lau back-arc basins, and the Futuna Volcanic Arc during the CHUBACARC cruise in 2019. Population structure, gonad morphology, and gametogenesis were analysed for each species, and fecundity was analysed for the two Lepetodrilus species. Both Lepetodrilus spp. were gonochoric and displayed a sexual size dimorphism with females larger than males. Gametogenesis was continuous or quasi-continuous with all stages of oocyte development present in the gonad and a maximum oocyte size of 124 µm for L. schrolli and 126 µm for L. fijiensis. Fecundity varied between 52 and 205 with a mean of 119 ± 74 (SD) matured oocytes per female in L. schrolli and between 80 and 605 with a mean of 366 ± 183 (SD) matured oocytes per female in L. fijiensis, and was independent of the limpet size for both species. Shinkailepas tollmanni is also a gonochoric gastropod with continuous gametogenesis and a maximum oocyte size of 153 µm. For each species, size-frequency distributions were consistent with a continuous recruitment although episodic larval supply could blur the signal. There was no evidence of an influence of the habitat type nor environmental conditions on population structures. [ABSTRACT FROM AUTHOR]

Simple Summary: Our study shows that the African citrus psyllid, a vector of Huanglongbing disease, prefers to develop at mild temperatures and is not well adapted to dry regions, where relative humidity is around or below 40%. Its life cycle is not completed or is severely delayed at temperatures above 30 °C and below 10 °C. Eggs are unable to hatch at constant temperatures below 8 °C or above 33 °C. Thus, T. erytreae establishment and spread will be maximum in regions with a temperate and humid climate, being rare in regions where dry weather conditions predominate. The African citrus psyllid, Trioza erytreae, is one of the two vectors of Huanglongbing, the most serious citrus disease worldwide. The first detection of T. erytreae in the European mainland was on the northwest of the Iberian Peninsula in 2014. Since then, the pest has spread throughout northern Spain (Galicia, Asturias, Cantabria, País Vasco) and along the western Atlantic coast of Portugal (from the Douro e Minho region to the Algarve). We conducted a series of laboratory experiments on lemon plants at different temperatures (from 8 to 34 °C) and humidity conditions (from 40 to 90%) to find out the influence of extreme temperatures and relative humidities (RHs) on the mortality, development and reproduction of T. erytreae. Our results show that temperatures above 30 °C and below 10 °C are very detrimental for nymphal development and nymphs were unable to reach the adult stage. Furthermore, eggs were unable to hatch under temperatures above 33 °C and below 8 °C. Adult mortality was highest at 34 °C and killed more than 50% of the population. We also found that relative humidity is crucial for the development and survival of T. erytreae. Nymphs were unable to reach the adult stage at an RH of 90% and 40%. Also, fecundity was significantly reduced at 90 and 40% RH, and fertility was lowest at 40% RH. Nymphal mortality was highest at an RH of 40%, which was the most detrimental humidity among all tested for the survival and development of T. erytreae. Our work concludes that T. erytreae establishment and spread will be maximum in regions with a temperate and humid climate, being rare in regions where dry and hot weather conditions predominate. [ABSTRACT FROM AUTHOR]

The two-spotted spider mite Tetranychus urticae Koch, the date palm dust mite Oligonychus afrasiaticus (McGregor), and the citrus brown mite Eutetranychus orientalis (Klein) of family Tetranychidae are key pests of fruit trees, field crops, and ornamentals that cause significant yield losses. The purpose of this research was to assess the effect of three constant temperatures (22, 27, and 32 °C) on the developmental time, life-table parameters, and consumption rate of the predatory beetle Stethorus gilvifrons (Mulsant) on maize leaf disks with T. urticae, O. afrasiaticus, and E. orientalis as food. The results indicated a significant difference between the three different temperatures and prey types. The shortest developmental time was recorded on T. urticae (9.30 and 10.10 days) at 32 °C, while the longest was on E. orientalis (23.34 and 22.50) at 22 °C for females and males, respectively. The shortest female longevity was on E. orientalis (21.14 days) at 32 °C, and the longest was 39.12 days on T. urticae at 22 °C. The fecundity increased as temperature increased, from 114.6 eggs with a daily rate of 3.81 eggs per female/day at 22 °C to 235.0 eggs with a daily rate of 10.78 eggs per female/day at 32 °C on T. urticae. The highest net reproductive rate (R0), intrinsic rate of natural increase (rm), and finite rate of increase (λ) were recorded at 32 °C, whereas the lowest values were recorded at 22 °C when predatory beetles S. gilvifrons were fed on three prey diets. Gross reproduction rate (GRR) recorded the highest value (132.8 offspring/individual) when fed on T. urticae at 32 °C and the lowest value (55.30 offspring/individual) when fed on E. orientalis at 22 °C. The highest consumption rate of adult males and females was 226.8 and 245.4 individuals when fed on O. afrasiaticus at 22 °C, while the lowest was 123.6 and 133.8 individuals on E. orientalis at 32 °C. Thus, the results obtained here revealed that temperature and prey diets influence the developmental rate and reproduction of S. gilvifrons. Additionally, T. urticae is better for mass rearing of S. gilvifrons than O. afrasiaticus and E. orientalis as food. [ABSTRACT FROM AUTHOR]

Food supply stands out as one of the most critical drivers of population demographics by limiting reproductive rates. In this study, we assessed fluctuations in diet composition and monitored various reproductive parameters over a nine-year period in a Golden Eagle population in an Eastern European peatland. The identification of 2439 prey specimens from 84 species revealed that the studied eagles primarily preyed upon birds (constituting 78.3% of prey numbers and 67.2% of prey biomass) and less on mammals (21.6% and 32.8%, respectively). Grouse emerged as the most important prey group (31% and 27%), followed by waterfowl (17%) and hares (8% and 14%). The most significant prey species, both in terms of numbers and weight, were the Black Grouse, Mountain Hare, Common Crane, and Capercaillie. The share of the Black Grouse decreased, while those of the White-fronted Goose, Roe Deer, and hares increased. The food niche, as measured by the Levins' index, was broad (6.6), and it expanded during the study. On average, 58.3% of Golden Eagle pairs initiated breeding annually, with 69.1% successfully completing it, and 0.41 young per occupied territory were produced annually; there was pronounced interannual variation in reproductive performance. These fluctuations were associated with the shares of White-fronted Goose, Capercaillie, Mountain Hare and Roe Deer in the diet, suggesting that these species may be gaining increasing importance for the Golden Eagle, particularly following the decline of the Black Grouse. [ABSTRACT FROM AUTHOR]

Copyright of Agronomía & Ambiente is the property of Universidad de Buenos Aires. Facultad de Agronomia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Context. Overabundant native wildlife can pose serious challenges for managers. The most direct, immediate way to reduce density-dependent impacts is by culling, but lethal control often lacks public support. Fertility control offers a non-lethal management alternative. Aims. We conducted two fertility-control projects on eastern grey kangaroos (Macropus giganteus), a common and widespread species in Australia. We aimed to evaluate three key components of an integrated fertility-control project, namely, delivery efficiency, contraceptive efficacy and population-level outcomes. Methods. The two study sites on the urban fringe of Melbourne, Australia, were small reserves. Both had undergone an irruptive peak and subsequent crash, with negative impacts on animal health. Gresswell Forest (52 ha) is open forest habitat enclosed by a kangaroo-proof fence. Serendip Sanctuary (250 ha) is grassy woodland and retired pasture, with a boundary allowing kangaroo movement onto neighbouring properties. We captured kangaroos with a dart gun at night and treated all healthy adult females with subdermal levonorgestrel implants. Key results. Delivery efficiency (catch-per-unit effort) was greater from a vehicle at Serendip Sanctuary than on foot at Gresswell Forest, with only a marginal decline over successive nights at both sites. Background fecundity was 91% at Serendip Sanctuary, but close to zero at Gresswell Forest. Treatment efficacy was high, being 86–100% infertility at Serendip Sanctuary and 96–100% at Gresswell Forest. At Serendip Sanctuary, the proportion of females treated never reached 75%, whereas only one female at Gresswell Forest remained untreated after 3 years. Population density at Serendip Sanctuary exceeded the target range 3 years after culling and fertility control. No culling occurred at Gresswell Forest, but fertility control apparently held population density at a moderate level, albeit much higher than the density target. Conclusions. Future management at Serendip Sanctuary and Gresswell Forest will require a sustained fertility-control effort. Further culling may also be required to complement fertility control at Serendip Sanctuary, the larger, open site. Implications. Contraceptive efficacy of levonorgestrel is high in kangaroos and implants can be delivered efficiently, but achieving control of a large, open population will be challenging. [ABSTRACT FROM AUTHOR]

Diaeretiella rapae (McIntosh) is a potential biocontrol agent of the mustard aphid, Lipaphis erysimi (Kaltenbach). Its oviposition and fecundity activities are studied. Oviposition is mainly confined to the abdomen of the host aphid. The time taken for oviposition varied from 40-60 seconds. This time is influenced by the age of female D. rapae. Fecundity reached 100-325 eggs per female during her lifetime. The average total number of eggs laid per female was recorded at 178. Increasing the age of females reduces fecundity. The young mated female laid more eggs than old females. Various authors reported variable reproductive capability in different aphidiid wasps. [ABSTRACT FROM AUTHOR]

With a generally warming global climate, the number of Tetranychus truncatus specimens in the Hexi region in China has been increasing. As ectotherms, the growth and development of T. truncatus are greatly affected by changes in environmental temperature. The effect of heatwaves on organisms depends on a delicate balance between damage and repair periods. Therefore, we simulated nine patterns of periodically recurring changes in the frequency of high-temperature days using an intraday gradual temperature change model to study and compare the effects on the development and reproduction of pyridaben-sensitive and -resistant strains of T. truncatus. The results showed that the influence of the frequency of high-temperature days on developmental stages, longevity and fecundity was different between the two strains. The egg and immature stages of the sensitive strain were all affected by hot days, whereas the adult stage was less affected by the frequency. The egg stage of the resistant strain was less affected; it was mainly affected in the immature and adult stages. Under the moderate condition of increasing the proportion of days at normal temperature, the longevity of the resistant strain gradually increased and reached a maximum at a 1:3 frequency, and then it decreased with the increase in high-temperature days. The longevity of the sensitive strain was less affected by frequency, and there was no significant difference between most treatment and control groups. In addition, both sensitive and resistant strains were able to complete growth and development under all nine frequencies of high-temperature days, but the reproductive rate was lower than it was at normal temperatures, indicating that both strains of T. truncatus adapted to high temperatures at the expense of reduced reproduction rates. This lays a key theoretical foundation for predicting the occurrence of agricultural pest populations under the background of climate warming and developing appropriate control strategies. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Entomology is the property of Chinese Journal of Applied Entomology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Macrognathus is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes. The majority of South and Southeast Asia is home to these fish. The major food category of this genus is crustaceans (such as prawns) and aquatic insects (Chaoborus spp.), while juveniles mostly consume annelids (such as earthworms). According to various studies, it was found that the male: female ratio of Macrognathus sp is roughly 1:1. Macrognathus exhibit a wide range of fecundity, and the number of ova or eggs laid by a single female depends on several variables, including size, age, species, and the ecological habitats of the fish, including the availability of food. The fecundity of these fishes is found to be high when the fish were breeding, which occurred from May through August. The average ovarian diameter of M. pancalus has been found to increase every month. In some studies, lentic habitats showed higher ova diameter than lotic habitats for Macrognathus sp. For Macrognathus sp. the males matured at lengths of 10 to 11 cm and females at lengths of 11 to 12 cm on the other hand M. aral was found to be matured at an average of 12.05 cm for males and 16.05 cm for females. [ABSTRACT FROM AUTHOR]