Current Organizations / Institutes

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Abdulrhman Almadiy has a total of 49 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Trophic transfer of heavy metals across a food chain in a wastewater-irrigated agroecosystem

    by Mustafa Soliman, Rasha Al-Akeel, Mariam Al-Ghamdi, Abdulrhman Almadiy, Sayed Rawi, Wei Zhang, Hathal Al Dhafer, Amr Mohamed, Yahya Al Naggar, Abeer M. Salem

    Wastewater irrigation is often practiced in arid regions, which can increase the chance of heavy metals contaminating the agricultural system. This contamination poses risks to both the environment and human health. This research looked into how cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) move through a food chain involving soil, plants, and arthropods. The study was conducted in El-Gabal El-Asfar, Egypt, comparing treated and untreated wastewater irrigation areas. Six soil-irrigated sites and one reference site were sampled for soil, alfalfa (Medicago sativa), two grasshopper species (Aiolopus thalassinus and Calephorus compressicornis), and a wolf spider (Hogna ferox). The samples were analyzed for their heavy metal content. Metal concentrations in all components of the wastewater irrigated system were significantly higher compared to the reference site. The wolf spider and the soil contained the highest levels of Cd, Pb, and Cu, while the greatest concentrations of Zn were found in the spider and grasshoppers. Despite limited transfer from soil to plant, trace elements biomagnified within the terrestrial food chain, specifically from grasshoppers to wolf spiders. The correlation analysis of metal levels between soils, plants, and arthropods in the present study reflects its transfer across the trophic levels. It suggests that dietary intake is the main source of metal accumulation in arthropods. The present study, therefore, quite clearly indicated the possibility of heavy metal biomagnification in terrestrial food chains of wastewater-irrigated agroecosystems. Continuous monitoring and management of such systems are advocated to avoid environmental and public health risks.


  • Open Access

    Limited genetic variability and spatial population structure in grasshoppers between natural and metal-contaminated areas in Egypt

    by Mustafa Soliman, Abdulrhman Almadiy, Rasha Al-Akeel, Thomas Hesselberg, Amr Mohamed

    Pollutants in an environment can have long-term implications for the species living there, resulting in local adaptations with implications for their genetic structure. Heavy metal pollutants infiltrate soils and groundwater, bioaccumulate in food webs, and negatively impact biota. In this study, we investigated the degree to which the genetic structure and variability of the slender green-winged grasshopper (Aiolopus thalassinus (Fabricius) (Orthoptera: Acrididae)) were impacted by heavy metal pollution and distance. We used the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) method to examine the genetic variability of populations in 3 heavy metal-polluted and 3 unpolluted locations across varying geographical distances in Egypt. The heavy metal concentrations of cadmium, copper, lead, and zinc were measured from the grasshopper tissue and soils. Sixty-nine unique and polymorphic bands were produced by 4 primers. Cluster and principal component analyses separated the populations inside and outside Cairo into 2 main branches, which were further divided into smaller branches corresponding to their geographical regions. We found no differences in the Shannon genetic diversity index between populations or with increasing heavy metal concentrations in either the soil or the grasshopper tissue. Our results showed a greater genetic variation among populations than between populations within the same location, indicating populations within locations were less differentiated than those between locations. The moderate correlation between genetic similarity and spatial distance suggests geographical isolation influenced grasshopper population differentiation. Based on the RAPD analysis, environmental pollutants and geographical distances impact the A. thalassinus population structure, potentially restricting gene flow between sites even at small spatial scales.


  • Eicosanoids and biogenic monoamines modulate the nodulation process and phenoloxidase activity in flesh flies

    by Moataza A. Dorrah, Mona M. Ali, Rasha K. Al‑Akeel, Mariam S. Al‑Ghamdi, Abdulrhman A. Almadiy, Taha T. M. Bassal


  • Open Access

    Partially substituting chemical NPK fertilizers and their impact on Eureka lemon trees (Citrus limon L. Burm) productivity and fruit quality

    by Abdulrhman A. Almadiy, Ayman E. Shaban, Ammar M. Ibrahim, Salem M. Balhareth, Sherif F. El-Gioushy, El-Sayed G. Khater

    The main aim of this study is to improve productivity, physical and chemical properties of the fruits and fruit quality of Eureka Lemon trees while lowering production costs by investigating the use of different NPK alternative sources (slow release, and bio) to reduce the use of chemical NPK fertilizers. Ten treatments of NPK fertilizers were applied. The results indicate that the highest values of yield (111.0 and 114.0 kg/tree) were found with 100% chemical NPK (control) for both first and second seasons, respectively. The lemon fruit weight ranged from 131.3 to 152.4 and 131.4 to 153.5 g for first and second seasons, respectively, for all treatments under study. The highest values of fruit length and fruit diameter were found with 100% chemical NPK (control) for both two seasons. The highest values of juice quality parameters (TSS, juice acidity, TSS/acid ratio and vitamin C concentration) responded favorably to higher chemical NPK treatment rates. The highest values of TSS, juice acidity, TSS/Acid ratio, and vitamin C concentration were 9.45%, 6.25%, 1.524 and 4.27 mg/100 g, respectively, were found with 100% chemical NPK (control) for both two seasons. Meanwhile, the lowest value of total sugar was found with 100% chemical NPK (control) for both two seasons.


  • Qualitative structure-activity relationships of aryl isoprenoid derivatives as biorational juvenoids — reweighing

    by Abdulrhman A. Almadiy, Mariam S. Al-Ghamdi, Rasha K. Al-Akeel, Mustafa M. Soliman, Mona M. Ali

    Juvenoids are juvenile hormone (JH) mimetics, with specific structural features and defined molecular size that disrupt the target insect development. Juvenoid activity (= JH-type activity) of various isoprenoid-based derivatives as insecticidal candidates of the insect growth disruptors (IGDs) type were rated against the house fly, Musca domestica L. The epoxidized decenyl and nonenyl phenyl ether derivatives have more active compounds than those of both parent alkoxidized or olefinic structures. The highest juvenoid potency was shown by 3,4-methylenedioxyphenyl ethers of 8,9-epoxy-5,9-dimethy1-3,8-decadiene. Qualitative structure-activity relationships are offered to relate the chemical structure criteria to observed juvenoid-related activity. Differences in activity among the reported isoprenoid-based derivatives were qualitatively rationalized. This study advances understanding of the structural qualifications and activity determinants of isoprenoid juvenoids, which is important for the development of new filth flies eco-friendly insecticides.


  • Open Access

    Cupressus sempervirens Essential Oil, Nanoemulsion, and Major Terpenes as Sustainable Green Pesticides against the Rice Weevil

    by Abdulrhman A. Almadiy, Gomah E. Nenaah, Bader Z. Albogami, Dalia M. Shawer, Saeed Alasmari

    In order to find effective, biorational, and eco-friendly pest control tools, Cupressus sempervirens var. horizontalis essential oil (EO) was produced using hydrodistillation, before being analyzed with gas chromatography, specifically, using flame ionization detection. The monoterpene components α-pinene (46.3%), δ-3-carene (22.7%), and α-cedrol, a sesquiterpene hydrocarbon, (5.8%), were the main fractions. An oil-in-water nanoemulsion was obtained following a green protocol. The EO, its nanoemulsion, and its terpenes each exhibited both insecticidal and insect repellent activities against the rice weevil, Sitophilus oryzae. In a contact bioassay, the nanoemulsion induced a 100% adult mortality rate in a concentration of 10.0 µL/cm2 after 4 days of treatment, whereas 40 µL/cm2 of EO and α-cedrol was required to kill 100% of weevils. Using fumigation, nanoemulsion and EO at 10 µL/L air caused a 100% adult mortality rate after 4 days of treatment. The LC50 values of botanicals ranged between 5.8 and 53.4 µL/cm2 for contact, and between 4.1 and 19.6 µL/L for fumigation. The phytochemicals strongly repelled the weevil at concentrations between 0.11 and 0.88 µL/cm2, as well as considerably inhibiting AChE bioactivity. They were found to be safe for earthworms (Eisenia fetida) at 200 mg/kg, which also caused no significant alteration in wheat grain viability. This study provides evidence for the potential of using the EO of C. sempervirens and its nanoemulsion as natural, eco-friendly grain protectants against S. oryzae.


  • Open Access

    Growth Optimization and Rearing of Mealworm (Tenebrio molitor L.) as a Sustainable Food Source

    by Kanwal Riaz, Toheed Iqbal, Sarzamin Khan, Amjad Usman, Mariam S. Al-Ghamdi, Ashwag Shami, Rania Ali El Hadi Mohamed, Abdulrahman A. Almadiy, Fahd Mohammed Abd Al Galil, Nawal Abdulaziz Alfuhaid, et al.

    As a sustainable food source for humans, mealworms (Tenebrio molitor) have a great deal of potential, due to the fact that they have a very favorable nutritional profile and a low environmental impact. For meal production, feed formulation and optimization are important. The mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) is the most consumed insect in the world. Mealworms were given a variety of diets, including wheat bran as constant diet supplemented with different levels of Ospor (Bacillus clausii) at 0.002 g, 0.004 g, 0.006 g, and 0.008 g; imutec (Lacticaseibacillus rhamnosus) at 0.2 g. 0.4 g, 0.6 g, and 0.8 g; fungi (Calocybe indica) at 250 g, 500 g, and 750 g; yeast (Saccharomyces cerevisiae) at 50 g, 100 g, and 150 g; and wheat bran (standard diet) were examined in complete randomized design (CRD). Different parameters, i.e., the larval, pupal, and adult weight, size, life span, and nutritional profile of mealworm were studied. When compared with other insect growth promoters, only wheat bran was discovered to be the most efficient. It generated the heaviest and longest larvae at 65.03 mg and 18.32 mm, respectively, as well as pupae weighing 107.55 mg and 19.94 mm, respectively, and adults weighing 87.52 mg and 20.26 mm, respectively. It was also determined that fungi (C. indica) and ospor (B. clausii) promoted faster larval development than yeast (S. cerevisiae) and imutec (L. rhamnosus). Larval mortality was also greater in the imutec (L. rhamnosus) and yeast (S. cerevisiae) diets than the others. No pupal mortality was recorded in all diets. Furthermore, the protein content of Tenebrio. molitor raised on a diet including fungi (C. indica) was the highest at (375 g), with a content of 68.31%, followed by a concentration of (250 g) with a content of 67.84%, and wheat bran (1 kg) (normal diet) with the lowest content at 58.91%. T. molitor larvae fed a diet supplemented with bacterial and fungal had lower fat and ash content than bran-fed T. molitor larvae (standard diet). Wheat bran (normal diet) had the highest fat at 16.11%, and ash at 7.71%. Hence, it is concluded that wheat bran alone or diet containing fungi (C. indica) and ospor (B. clausii) performed better in terms of growth, and these diets and protein content are recommended for the mass rearing of mealworms.


  • Open Access

    Spatiotemporal Distribution Patterns of Pest Species (Lepidoptera: Noctuidae) Affected by Meteorological Factors in an Agroecosystem

    by Zafar Hussain, Zahid Mahmood Sarwar, Atif Akbar, Sadeq K. Alhag, Nazeer Ahmed, Pravej Alam, Abdulrahman A. Almadiy, Ferjeni Zouidi, Nilesh Baburao Jawalkar

    Knowing pests’ spatiotemporal distribution patterns is essential for forecasting population outbreaks and designing control tactics or long-term management plans. The family Noctuidae is one of the largest families of the Lepidoptera order. The noctuid’s moths are well represented in all zoogeographic regions in various habitats and have immeasurable ecological and economic importance. Although the species’ ecology has been extensively studied, little is known about the spatial and temporal distribution patterns of noctuid moths in an agroecosystem. Therefore, in this study, the spatial and temporal fluctuations in the abundance of 24 important species in the family were quantified. Yellow light traps were mounted in 11 different selected localities of the Multan district. The maximum species abundance was observed in September but declined in December, January, and February. Spatial contour maps were used to determine the species’ dissemination over space. Meteorological factors such as temperature and humidity showed a significantly positive correlation, while rainfall showed a significantly negative correlation, with species richness. The maximum species abundance was recorded in crop areas as compared to forest areas. This study provides a scientific basis for developing and timely applying control strategies for localized pest control.


  • Open Access

    Toxicological Effects of Silver and Zinc Oxide Nanoparticles on the Biological and Life Table Parameters of Helicoverpa armigera (Noctuidae: Lepidoptera)

    by Muhammad Shahbaz Asghar, Zahid Mahmood Sarwar, Abdulrahman A. Almadiy, Ashwag Shami, Rania Ali El Hadi Mohamed, Nazeer Ahmed, Minakshi Sanjay Waghulade, Pravej Alam, Fahd Mohammed Abd Al Galil

    American bollworm Helicoverpa armigera (Hubner) is a notorious pest of different agronomical and horticultural crops. Different synthetic insecticides are recommended to control H. armigera but widespread and repeated use has led to pesticide resistance in this pest. It is, therefore, necessary to develop a novel strategy to manage the population of H. armigera. Nanotechnology is the most effective and eco-friendly approach to mitigate this problem. In the present study, the bioefficacy of green synthesized nanoparticles and two different silver and zinc oxide nanoparticles with different concentrations, viz. 100, 125, 150, 175 and 200 ppm were used against the larvae. UV-vis spectrophotometer, SEM and EDX were used for nanoparticle characterization. Data were recorded daily. The result showed that in silver nanoparticles maximum larval mortality was 97%, while in zinc oxide nanoparticles, 82% was recorded against the 3rd, 4th and 5th instar of H. armigera. The effect of nanoparticles on demographic parameters was also evaluated, which increases the net reproductive rates, mean generation time and intrinsic rate in the control group compared to the treated population. After bioassay, larval and pupal duration was prolonged in the treated population compared to the control. The longevity of males, females and fecundity was also reduced. This technique will be a valuable tool in integrated pest management regimens.


  • Essential oil of Origanum vulgare, its nanoemulsion and bioactive monoterpenes as eco-friendly novel green pesticides for controlling Aedes aegypti, the common vector of Dengue virus

    by Abdulrhman A. Almadiy, Gomah E. Nenaah

    Essential oil (EO) of Origanum vulgare L. was hydrodistilled and analysed using gas chromatography–flame ionization detection and gas chromatography–mass spectrometry. The monoterpenes, carvacrol (61.2%), γ-terpinene (9.6%), thymol (8.3%), and p-cymene (5.7%) were identified. Oil-in-water nanoemulsion was prepared and characterized from the EO through a green procedure. Botanicals had a remarkable mosquitocidal and effectively inhibited acetylcholinesterase activity of Aedes aegypti. The nanoemulsion at 40 µg/ml caused 100% adult and larval mortality after 12 h. At 80 µg/ml, percentage mortality caused by EO products ranged between 55.11-100% for larvae, and 63.0 -100%. for adults After 24 h exposure, LC50's ranged between 13.2 and 75.7 µg/ml against larvae, and between 10.1 and 36.0 µg/ml against adults. The lethal time (LT50) decreased with nanoemulsion, EO and carvacrol. Test products were safe towards the non-target aquatic species, Gambusia affinis and Diplonychus indicus. Results recommend test botanicals as natural alternatives to control Ae. aegypti. Graphical Abstract