Post-reproductive Period Research Articles

Corticosterone treatment results in fat deposition and body mass maintenance without effects on feeding behaviour or immunity in female lizards (Tropidurus catalanensis)

Throughout life, animals must maintain homeostasis while coping with challenging events. The period after reproduction can be challenging for oviparous females to maintain homeostasis since they direct most of their energy stores to vitellogenesis, possibly increasing the vulnerability to stressors. Changes in glucocorticoids' (GC) secretion promote various behavioural and physiological adjustments daily and to restore balance after facing stressors. However, when GC are elevated for extended periods, which usually occurs in response to chronic exposure to stressors, they can affect feeding behaviour and suppress the immune function. We aim to elucidate the effects of chronic corticosterone (CORT) exposure on feeding behaviour, body condition and immune function in female lizards, Tropidurus catalanensis, in the post-reproductive period. Thirty animals were divided into three groups: 1. Control (no experimental procedure performed); 2. Empty Implant (animals implanted with empty silastic tube); and 3. CORT Implant (animals implanted with silastic tube filled with CORT, with a chronic continuous release for at least a week). CORT plasma levels feeding behaviour, body condition (body index [BI] and fat index [FI]), leukocyte count, and several immune function variables (bacterial killing ability [BKA], hemagglutination titer, phytohemagglutinin [PHA] immune challenge and leukocyte count) were evaluated. After implantation, CORT treated animals maintained stable body mass through the experiment, while Control and Empty Implant groups displayed weight loss. In the CORT treated animals, there was also a positive relation between BI and FI, and higher FI when compared to groups 1 and 2. No effects of CORT were observed on feeding behaviour nor on the immune function.

Use of Stable Isotopes (δ13C and δ15N) to Infer Post-Breeding Dispersal Strategies in Iberian Populations of the Kentish Plover.

Beaches are among the habitats most frequented by migratory birds for breeding and/or wintering. However, threats such as human pressure and sea level rise can reduce the availability of these habitats for different species. The presence of alternative areas, such as salt pans and brackish habitats, is essential for many migratory shorebird populations. This study addresses the post-breeding dispersal of the Kentish plover (Charadrius alexandrinus) in the Iberian Peninsula by analysing C and N isotopes in feathers. The study was conducted at six locations along the Iberian coast, which were categorized into three areas: the NW Atlantic coast, the Atlantic coast of Andalusia, and the Mediterranean coast. Although linear mixed models did not reveal any significant effects of sex or coastal area on isotopic levels, the variability in the data suggests different habitat-use strategies in the post-reproductive period. Isotopic levels in birds from the northwest of the Iberian Peninsula exhibit greater fidelity to a single habitat type, while those from the Mediterranean coast and the Atlantic coast of Andalusia show greater variability, indicating different individual dispersal strategies. The lack of alternative habitats for the northwest Iberian population, the reduction in available habitat due to rising sea levels, and human pressure together pose a serious threat to the survival of this species, already with an unfavourable conservation status.

Variation in reproductive parameters of Rhinella arenarum (Hensel, 1867) (Anura: Bufonidae) between the reproductive and post-reproductive periods

We compared reproductive parameters of Rhinella arenarum in a wetland of the Monte in Argentina during reproductive and post-reproductive seasons. Individuals were collected at random, monthly from November 2001 to October 2002. August through November was considered the reproductive period, and December through April was considered the post-reproductive period. Of the 116 adults, 75 were males and 41 were females. The reproductive parameters measured included body mass, fat body mass, number of mature ova, ova size, and testicular volume. There were significant differences between the reproductive and post-reproductive periods in females for body mass, fat body mass, and number of mature ova. Likewise, males also had significant differences between these periods for body mass and fat body mass. Apparently, R. arenarum has an opportunistic and continuous reproductive strategy. Entering dormancy with large fat bodies and testes in apparent spermatogenesis allows males to reproduce immediately after emerging in the spring. However, females have mature but fewer ova during this period, which is a reproductive feature shared by most temperate amphibians. Our data, and the primarily tropical distribution of R. arenarum, suggest that this species recently invaded the temperate region wherein males retained acyclic reproductive activity and females, owing to their higher reproductive costs, have evolved cyclic reproduction.

Comparative biology and life tables of sorghum aphid Melanaphis sorghi (Theobald) (Hemiptera: Aphididae) from Mexico, at different temperatures

The sorghum aphid Melanaphis sorghi (Theobald, 1904) is the most critical pest in sorghum crops grown in the USA and Mexico. The cultivated area of sorghum was reduced by more than 30% between 2016 and 2019 in northern Mexico, Guanajuato, Morelos, and other regions. This study provides essential information to support an Integrated Pest Management of this insect. M. sorghi field colonies from Guanajuato, Mexico, were identified by morphometric criteria and reared on Sorghum bicolor var. UPM-219 leaf discs using a bioclimatic chamber under different temperatures: 5, 10, 15, 20, 25, 30, 35 and 40 °C. The highest mortality occurred in extreme temperatures: 40 °C (100%). The lowest temperature assessed (5 °C) shows no reproduction, but the pre-reproductive period spread to 62.5 days, allowing an average of 88.2 days of the insects' survival. At 20 °C, M. sorghi produced a supernumerary N5 stage that prolonged the development by 7.1 days, while at the highest temperature (40 °C), N1s died after 0.9 days. The most prolonged reproductive period was 33.2 days (0.6 nymphs/day) at 10 °C, in contrast to 4.1 days (0.4 nymphs/day) at 35 °C. The most extended post-reproductive period (22.4 days) was observed at 10 °C and the shortest (4.2 days) at 35 °C. The highest fertility average (79.06 nymphs) was reached at 25 °C. The heat units required for each generation were 158.9, while theoretical thermal thresholds were 2.0 and 40 °C. Population parameters show that 25 °C is the optimal temperature for this aphid, estimating Ro (79.06), Rm (0.44), T (10.01), DT (1.59), and λ (1.55).

Reproduction Period Of Javanese Women

A woman's reproductive life goes through several phases including menstruation, childbirth and menopause. The first menstrual event experienced by a woman is called menarche, while the end of the menstrual period is called menopause. The age intervals for menarche and menopause describe the reproductive period or fertile age for a woman to become pregnant and give birth. The postreproductive period characterized by menopause is related to a woman's life expectancy and is important for assessing the quality of life. This research aims to determine the reproductive period of Javanese women in Oransbari, South Manokwari Regency. Cross-sectional research was conducted on women with an average age of 51.73 years with an interval of 40.18-69.59 years. The inclusion criteria were women who had experienced menopause. The age of menarche and menopause were analyzed using the Generalized Linear Model (GLM) in the R program. We found that the age at menarche (12.3 years) and age at menopause (43.1 years) of Javanese women in Oransbari were relatively young. This condition results in a shorter reproductive period (30.8 years) compared to several populations in Indonesia such as Sunda, Baduy, Tengger, Lampung, and Semendo. The reproductive period, which tends to be short, might be an adaptive response to environmental challenges that were less favourable as a pioneer transmigration society, such as high physical activity and low socio-economic conditions. The biocultural conditions experienced in the early life of Oransbari form a reproductive period that starts and ends early as an adaptive response to maximize reproductive success. Thus, women's reproductive health especially communities in isolated and remote areas, needs to be studied and become one of the government's focuses in considering intervention policies related to the health and welfare of the elderly and demographics

A method of diagnosing non-alcoholic fatty liver disease with the calculation of the steatosis index

Objective. To work out the index for diagnosing non-alcoholic fatty liver disease (NAFLD) in women with metabolic syndrome (MS) in postmenopause using generally available markers. Materials and methods. 62 females with NAFLD and MS in early postreproductive period took part in the study. They were compared to 24 relatively healthy females not suffering from obesity in postmenopause. The average age of the patients was 49,9 ± 1,1. Hepatic steatosis was diagnosed by ultrasound examination. The mathematic model of hepatic steatosis index (HSI) calculation included: body mass index (BMI), waist size (WS), triglycerides and low-density lipoproteins (LDL). Results. BMI and WS in patients with MS and NAFLD in postmenopause were considerably more than in relatively healthy women. Hypertriglyceridemia and an increase of LDL in blood serum were noted in patients with steatosis. Biometric and laboratory data were included in the mathematical formula which allows to calculate HSI. With HSI 0,5 and more NAFLD is diagnosed in women in post menopause, when HSI is lower than 0,5 it is not diagnosed. Indicators of sensitivity and specificity of the method were 98,4 % and 95,85 % respectively. Conclusions. The minimally invasive method suggested above allows to reveal hepatic steatosis in females with MS in early postreproductive period. High diagnostic characteristics of the method are worth mentioning, as well as the possibility to be widely used thanks to simple biometric and laboratory data employed.

Effects of nanoplastics exposure on ingestion, life history traits, and dimethyl sulfide production in rotifer Brachionus plicatilis

Microplastics (MPs) and nanoplastics (NPs) have gained global concern due to their detrimental effects on marine organisms. We investigated the effects of 80 nm polystyrene (PS) NPs on life history traits, ingestion, and dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) production in the rotifer Brachionus plicatilis. Fluorescently labeled 80 nm PS NPs were ingested by the rotifer B. plicatilis and accumulated in the digestive tract. The lethal rates of B. plicatilis exposed to NPs were dose-dependent. High concentrations of PS NPs exposure had negative effects on developmental duration, leading to prolonged embryonic development and pre-reproductive periods, shortened reproductive period, post-reproductive period, and lifespan in B. plicatilis. High concentrations of PS NPs exposure inhibited life table demographic parameters such as age-specific survivorship and fecundity, generation time, net reproductive rate, and life expectancy. Consequently, the population of B. plicatilis was adversely impacted. Furthermore, exposure to PS NPs resulted in a reduced ingestion rate in B. plicatilis, as well as a decreased in DMS, particulate DMSP (DMSPp) concentration, and DMSP lyase activity (DLA), which exhibited a dose-response relationship. B. plicatilis grazing promoted DLA and therefore increased DMS production. PS NPs exposure caused a decline in the increased DMS induced by rotifer grazing. Our results help to understand the ecotoxicity of NPs on rotifer and their impact on the biogeochemical cycle of dimethylated sulfur compounds.

Hematology of Liolaemus pacha (Iguania: Liolaemidae) and its relationship with mite infestation, reproductive period and body condition.

Variations in hematological profile in reptiles can be caused by multiple factors, including parasites presence. Our goals were to identify and morphologically describe blood cells of Liolaemus pacha and analyze their relationship with sex, body condition, individual reproductive/post-reproductive period and mite infestation. Blood smear analyses do not indicate the presence of hemoparasites, suggesting that the mites Neopterygosoma do not serve as vectors for these organisms, as has been proposed for other genera of ectoparasitic mites. In post-reproductive period, there was a reduction in specimens' body condition and a higher leukocyte count in uninfected lizards. This could be a consequence of the testosterone effects, in higher concentration during the reproductive season, which can increase the metabolic rate, decreasing feeding rate. Infested and non-infested lizards showed no differences in body condition, as well as in leukocyte count, hence the host's immune system could be developing infestation tolerance. Infested specimens had a higher count of monocytes, thrombocytes, heterophils and lymphocytes. Based on cells function, mites' effect could be associated with inflammatory processes, allergic reactions or infectious diseases. These results suggested a complex interaction between lizards' hematological parameters and factors associated to ectoparasites or body conditions. We consider this work as a diagnostic tool for genus Liolaemus, to evaluate health quality, with relevance to the conservation or management of this lizard's genus.

Variations in life history parameters, population dynamics, and transcriptome regulation of Brachionus plicatilis exposed to triclosan

Triclosan (TCS) poses an ecological health risk due to its lipophilic nature, long half-life, and bioconcentration. To evaluate the toxicity of TCS on aquatic organisms, the life history parameters, population dynamics, and transcriptome regulation of Brachionus plicatilis exposed to TCS were investigated. In this study, the fecundity of rotifers was promoted by 25 μg/L of TCS and inhibited by higher concentrations (100 μg/L, 200 μg/L). The reproductive period of rotifers was shortened by 46.24 % but the post-reproductive period was prolonged by 176.47 % in 200 μg/L TCS. Both population growth and life table parameters indicated that a high concentration of TCS (200 μg/L) had negative impacts on population growth. Transcriptomic analysis showed that the effects of TCS on the life history parameters and population dynamics of rotifers were determined by regulating the expression of functional genes in cilium organization and cilium assembly and involved in pathways of focal adhesion.

Роль менопаузальной гормональной терапии в вопросах профилактики сердечно-сосудистых заболеваний у женщин в пострепродуктивном периоде

Cardiovascular disorders (CVD) in female population are the main cause of mortality, and an increase in the prevalence of myocardial infarction among women is observed in the recent decades, in contrast to the male population showing a decrease in this indicator. Certainly, the mechanisms underlying CVD in people of different sexes have much in common, however, one cannot ignore the differences associated with fundamental genetic determinants of ageing, different characteristics of metabolism and fundamentally different types of hormonal status. It has been found that realization of activity of sex hormones is among major factors ensuring protection against cardiovascular disorders in premenopausal women. The increase in the rate of cardiovascular disorders and the lack of menopausal hormone therapy (MHT) prescription to women in their post-reproductive stage may be partially correlated. Aim. To analyze the data provided by advanced scientific research focused on prescription of menopausal hormone therapy (MHT) aimed at preventing cardiovascular disorders in the post-reproductive period. Methods. Analytical review of domestic and foreign papers on the topic, including using PubMed, Elseviewer, Cochrane library, Elibrary databases. Conclusions. Despite the fact that the issue of prevention and treatment of cardiovascular disorders attracts particular attention of global healthcare, CVDs still rank first in the world as the cause of deaths. In menopausal women, hypoestrogenism is among major pathogenetic links of cardiac abnormalities. To increase adherence of peri- and postmenopausal women to early diagnosis, general practitioners should give due consideration to referral of such women to obstetricians-gynecologists for timely correction of estrogen deficiency. It is also necessary to further study the issue in order to identify early diagnostic predictors of cardiovascular disorders.

Biology of aphid, Aphis gossypii Glover in cumin

The experiment on biology of aphid, Aphis gossypii infesting cumin crop was conducted under ambient conditions in the Entomology Laboratory, Agricultural Research Station, Mandor, Jodhpur. The study was conducted on potted plants of cumin variety GC-4. The aphid, A. gossypii nymphs were moulted four times before attaining the adult stage. The mean body length, width, antennal length and cornicle length of first, second, third and fourth instar nymphs were 0.50 ± 0.04, 0.28 ± 0.03, 0.28 ± 0.02 and 0.036 ± 0.01 mm; 0.90 ± 0.04, 0.38 ± 0.04, 0.40 ± 0.03 and 0.065 ± 0.01 mm; 1.11 ± 0.05, 0.49 ± 0.04, 0.54 ± 0.03 and 0.095 ± 0.01 mm and 1.31 ± 0.06, 0.65 ± 0.05, 0.64 ± 0.04 and 0.175 ± 0.01 mm, respectively. The mean body length, width, antennal length and cornicle length of adult aphid were 1.68 ± 0.06, 0.71 ± 1.53, 0.88 ± 0.02 and 0.266 ± 0.01 mm, respectively. The mean duration period of first, second, third and fourth instar nymphs were 1.30 ± 0.42, 2.05 ± 0.62, 2.40 ± 0.52 and 1.45 ± 0.45 days, respectively. The total nymphal duration was 7.75 ± 1.61 days. The mean longevity of adult aphid was 9.65 ± 1.75 days with an entire life span of 17.75 ± 2.91 days. The pre-reproductive, reproductive and post-reproductive periods were 1.35 ± 0.56, 7.20 ± 1.47 and 1.75 ± 0.71 days, respectively. The fecundity of the adult female was 24.45 ± 6.21 nymphs per female and the intrinsic rate of single female per day was an average of 4.80 ± 2.01 nymphs/day.

Effects of salinity on life history traits and fatty acid-binding proteins in the marine rotifer, Brachionus plicatilis

We present a comprehensive analysis of the impact of increased salinity on Brachionus plicatilis, focusing on growth, reproduction, behavior, and fatty acid-binding protein (FABP) gene expression. We discovered delays in maturation and potential disruptions in the reproductive process under conditions of high salinity. Experiments demonstrated that while the total number of B. plicatilis offspring remained unchanged across different salinity levels, the peak daily offspring count was delayed, and the pace of reproduction was slower at higher salinity. However, the pre-reproductive and reproductive periods at 35 practical saline units were extended, contributing to longer timeframes to produce all offspring, but the post-reproductive period was shortened, thus balancing the overall lifespan across different salinity levels. Furthermore, we noted that high salinity impedes the growth of B. plicatilis and causes alterations in swimming behavior. Our findings also demonstrated five pairs of FABPs within the three Brachionus species (B. plicatilis, B. rotundiformis, and B. koreanus) with distinctive sequences. Phylogenetic analysis revealed that Brachionus FABPs diverged before the speciation of the three species and were found outside the vertebrate FABP group. The results contribute to our understanding of the impact of high salinity on B. plicatilis and the evolutionary positioning of FABPs in these species, while also highlighting the need for further research into specific FABP differentiation and expression patterns in Brachionus species.

Biology of <i>Aphis gossypii</i> Glover on Cotton and Brinjal as Observed in Mass Rearing

The aptness of two hosts viz., cotton and brinjal for mass rearing of Aphis gossypii Glover under laboratory conditions was investigated using the age-stage and two-sex lifetable method. The results showed that A. gossypii could complete its entire lifecycle on both hosts. The total nymphal duration (7.93± 0.33 days), reproductive period (6.95± 0.60 days), adult longevity (8.11± 0.68 days) and fecundity (24.66± 2.34 days) were significantly higher on brinjal than on cotton. The differences in pre-reproductive and post-reproductive periods on both hosts were not statistically significant. The mean reproductive period was longer on brinjal (6.95± 0.56 days) than that on cotton (5.06± 0.47 days); consequently, the fecundity was also significantly high in brinjal (24.66± 2.34 nymphs/ female) compared to cotton (14.11± 1.31 nymphs/female). The difference in an intrinsic rate of increase, infinite rate of increase and doubling time were non-significant. In contrast, the net reproductive rate, gross reproduction rate, and mean generation time on brinjal were significantly higher. Lifetable parameters such as age-stage-specific survival rates, fecundity, life expectancy and reproductive value of A. gossypii were higher on brinjal compared to cotton. The results of this study indicate that brinjal is a better host than cotton for the mass rearing of A. gossypii.

Alopecia in Two Species of Insectivorous Bats during the Critical Time Period of Female Reproduction

Alopecia in bats has been related to multiple stressors, such as ectoparasite infestations, environmental contaminant exposure, idiopathic disease, and reproductive stress. Here we note occurrences of alopecia in 2 species of insectivorous bats, including a federally endangered species. In the summer of 2022, we encountered 3 Eptesicus fuscus (Big Brown Bat) and 7 Myotis grisescens (Gray Bat) with alopecia during mist-net and harp-trap surveys at multiple locations in Tennessee, USA. Seven of the 10 bats with bald spots were adult lactating or post-lactating females, 1 was an adult pregnant female, and 2 were adult nonreproductive males. No bats with alopecia were encountered after the lactation or post-lactation time period, despite continued mist-net and harp-trap surveys. The cause of the alopecia is unknown and warrants further investigation of prevalence across pre-reproductive (pre-pregnancy), reproductive (pregnancy, lactation, and spermatogenesis), and post-reproductive (pup volancy) periods in these populations. Understanding natural molt cycles versus alopecia as an outward sign of stress in individuals is critical for assessing the health of bat populations.

Factors Associated with Quality of Life among Menopausal Women in Lucknow - A Cross-Sectional Study.

Women who have gone at least a year without having their monthly period are considered as menopausal. Despite the fact that it is a physiological occurrence, its psychological, bodily, and sexual effects last for the entire postreproductive period. That's why it is important to research its various aspects and the different parameters associated with their quality of life (QoL). To find the association of the QoL among menopausal women in Lucknow with various socio-demographic variables, body mass index, chronic disease status, and other lifestyle parameters. A community-based cross-sectional study was conducted from February 2020 to January 2021 among 200 Menopausal women of 45-65 years by using a pretested semi-structured questionnaire. The study was carried out in rural and urban field practice areas of the Community Medicine Department, King George's Medical University, UP, Lucknow. The mean score of vasomotor domains was found higher in the age group of 45-49 years, who had higher education level, upper and upper middle class of socioeconomic status, and for obese study participants. The mean score of the sexual domain was found to be higher among the age group 55-59 years, married study participants, for those who were educated above secondary, and for overweight and obese. The mean scores for all domains, i.e., vasomotor psychosocial physical and sexual domains were higher for those who had chronic diseases. Overall, the menopause specific QoL score was higher for those who did not use lifestyle modification as compared to those who used lifestyle modification and the difference was found to be highly significant (P < 0.001).

Current Trends and Approaches to the Search for Genetic Determinants of Aging and Longevity.

The online version contains supplementary material available at 10.1134/S1022795422120067.

Striking Variability in the Post-Reproductive Movements of Spanish Red Kites (Milvus milvus): Three Strategies, Sex Differences, and Changes over Time.

It was assumed that the Spanish breeding population of the red kite (Milvus milvus) was resident, hence their movements were restricted to their breeding area for their entire lifecycle. However, recent observations indicated that the post-reproductive strategies of the red kite in Spain are more diverse. We tagged 47 breeding adult red kites in Spain and analyzed their movements during the post-reproductive period (July-February). We found three strategies in the population: migration (10%), sedentarism (70%), and sedentarism with post-reproductive movements (20%), based on seasonality and other movement parameters. Sedentarism with post-reproductive movements was a very variable strategy that involved all-direction wandering movements far away from the nest (up to 589 km) after breeding season, and then a returned journey toward the starting point in time for the next breeding season. Our results also suggest that sedentarism with post-reproductive movements is much more common in females than males. Furthermore, 17% of the individuals changed their strategy over the years. This study highlights the great individual variability and plasticity of the red kite and allows for a better understanding of spatial ecology in opportunistic raptors.

Genetic identification and comparative study on life history parameters of two strains belonging to Brachionus plicatilis species complex (Rotifera: Monogononta)

The rotifer Brachionus plicatilis is an important species for aquaculture, due to its use as food for bivalves, and fish and crustaceans larvae in hatcheries. However, being a species complex, it has become increasingly important to catalogue and describe the species and biotypes that constitute this complex. Therefore, the purpose of this study was to genetically identify two morphologically identical strains and evaluate their suitability to be used in aquaculture under the studied conditions. A correct identification and knowledge of life history characteristics of the biotypes and isolated strains is vital to avoid mass mortalities in aquaculture and to better interpret the responses of the organisms when these are used as a bioindicator and model for ecotoxicology. Strains MRS10 and IBA3 were identified as B. koreanus and, even though they have been maintained under the same laboratory conditions for several years, significant differences in several life history parameters were observed. A life table assay showed IBA3 rotifers to be larger at first reproduction, and to have longer post-reproductive period and mean lifespan. On the other hand, MRS10 rotifers produced less non-viable eggs and had higher population growth rate. Both strains showed to be a potential model for ecotoxicological and molecular studies, mainly due to the ease of maintenance, short generation time, and reproduction via parthenogenesis. However, MRS10 might present better characteristics than IBA3 to be reared in aquaculture as live food.

Chromosome Segregation in the Oocyte: What Goes Wrong during Aging.

Human female fertility and reproductive lifespan decrease significantly with age, resulting in an extended post-reproductive period. The central dogma in human female reproduction contains two important aspects. One is the pool of oocytes in the human ovary (the ovarian reserve; approximately 106 at birth), which diminishes throughout life until menopause around the age of 50 (approximately 103 oocytes) in women. The second is the quality of oocytes, including the correctness of meiotic divisions, among other factors. Notably, the increased rate of sub- and infertility, aneuploidy, miscarriages, and birth defects are associated with advanced maternal age, especially in women above 35 years of age. This postponement is also relevant for human evolution; decades ago, the female aging-related fertility drop was not as important as it is today because women were having their children at a younger age. Spindle assembly is crucial for chromosome segregation during each cell division and oocyte maturation, making it an important event for euploidy. Consequently, aberrations in this segregation process, especially during the first meiotic division in human eggs, can lead to implantation failure or spontaneous abortion. Today, human reproductive medicine is also facing a high prevalence of aneuploidy, even in young females. However, the shift in the reproductive phase of humans and the strong increase in errors make the problem much more dramatic at later stages of the female reproductive phase. Aneuploidy in human eggs could be the result of the non-disjunction of entire chromosomes or sister chromatids during oocyte meiosis, but partial or segmental aneuploidies are also relevant. In this review, we intend to describe the relevance of the spindle apparatus during oocyte maturation for proper chromosome segregation in the context of maternal aging and the female reproductive lifespan.

Soil pH alters the biological parameters of cowpea aphid Aphis craccivora Koch (Hemiptera: Aphididae) on its host plant Vicia faba

The biotic and abiotic factors including the agricultural implementation can modify soil acidification. We hypothesized that soil pH should as repercussion, alter the plant physiological and physical properties and eventually affect insect herbivores including agricultural pests. This study aimed to evaluate the impact of seven levels of soil pH on the performance of cowpea aphid Aphis craccivora on Vicia faba. Significant relationships between soil pH and growth of host bean seedlings or development and reproduction of the aphid were detected. Data demonstrated significant differences in the total longevity, the pre-reproductive, reproductive, post-reproductive and pre-viviparity periods. Within a suitable range of pH for bean growth between pH 5.3 and pH 7.2, the aphid performance was worse on seedlings growing better, however, under unfavorable extreme pH conditions, plant quality measured as height did not affect the aphids anymore and their performance was uniformly low except the case in pH 8.1 condition in which the best aphid reproduction was observed. The results confirm that soil pH affect the performance of cowpea aphid A. craccivora and also exhibited strong influence on the growth of broad bean plants.