In Africa, the production of vegetables and fruits represents an important field in agriculture (Aworh, 2021), including tomato (Lycopersicum esculentum L.) (1768), one of the most popular and commonly grown vegetable crops worldwide. This fruit is a source of potassium, delycopene (antioxidant, anticancer agent), polyphenols and ascorbic acid (Vit C) (Rao et al., 2018; Wang et al., 2023). As well as plum trees with a low-calorie content and a low glycemic index, but a relatively high nutritional value. They contain carbohydrates, primarily sucrose, glucose and fructose, organic acids, e.g (Arslan et al., 2023). citric and maleic acids, fibers (pectins), tannins, aromatic substances, chlorophyll, carotenoids, anthocyanins and enzymes, These substances determine the nutritional value and taste of plums (Ayub et al., 2023). Plum is a fruit rich in phenolic compounds, characterized by a relatively high antioxidant activity, higher than that of orange, apple or strawberries, also rich in minerals and vitamins (C, A, B1, B2) (Maji and Cornelius, 2023; Manzoor et al., 2023).
       
Tomato and plum are susceptible to insects causing considerable yield reductio. T. absoluta is one of the most important tomato pests in open field and greenhouse cropping systems, which invaded Algeria in 2008 (Guenaoui and Ghelamallah, 2008). Considerable economic losses are caused by larvae that mine tomato plants to feed on leaf, stem and fruit mesophile (Yadav et al., 2022).
       
Numerous pests have also been reported on plum trees, which requires well-organized measures to protect fruits, leaves and wood. The most important pests from an economic point of view are plum flies and certain aphids such as H. pruni, previously considered the most dangerous pest (Lozier et al., 2009). H. pruni damage shoots almost throughout the growing season which retards their development (Jordan et al., 2021; Vasilev et al., 2019).
       
Chemical control has always been considered an efficient approach of controlling T. absoluta and H. pruni populations. However, this method remains expensive and unstable due to the development of insect resistance and the negative impact noted on the environment and human health.
       
Plants are natural resources that have long been applied to monitor various agricultural pests (Divekar, 2023; Hajjar et al., 2023). Natural substances can be exploited as biopesticides, such as extracts of medicinal plants and antagonists of natural origin (Tarusikirwa et al., 2020). Typically, plant extracts, which are more environmentally friendly, have been widely used as substitute to chemical pesticides (Abdullah and Zahoor, 2023; Ayilara et al., 2023). The insecticidal activity of botanical extracts has been investigated in various reports (da Silva Sá et al., 2023; Lengai et al., 2020).
       
Stinging nettle,often known as common nettle, burn nettle, stinging nettle or nettle leaf is one of the plant species adopted by man as a bioactive substance in traditional medicine and agriculture (Bhusal et al., 2022), This plant is very rich in secondary metabolites which has several pharmacological properties (Majedi et al., 2021)  including  antibacterial, antifungal (Rolta et al., 2020; Taheri et al., 2022); anthelminthic (Bhusal et al., 2022); anticancer (Sharifi-Rad et al., 2021), antioxidant (Jaiswal and Lee, 2022) and anti-inflammatory (Scheau et al., 2021) anti-aging (Sifaki et al., 2020) and antiviral activity (Upreti et al., 2023). U. dioica is considered an ecological keystone species and very important for biodiversity (Subba and Pradhan, 2022), It is also used as a natural feed additive in poultry nutrition (Mehboob et al., 2025). among nettle derivatives, manure is the most used by farmers, its use is explained by the results obtained and the simplicity of its manufacture and its use. Nettle manure is used as a fertilizer, as a fungicide against mildew, as an insecticide against aphids and ticks and as a plant growth activator or regulator (Koczkodaj et al., 2023; Opačić et al., 2022).
       
In this context, we are interested in the study of the insecticidal activity of methanolic extracts of leaves and roots of U. dioïca L. against the pests of T. absoluta and H. pruni crops.

Extraction of polyphenols from leaves and roots
 
The plant material used in this study was collected in March 2022 from the Mostaganem region, Algeria. The extraction procedure was performed at the Biochemistry Laboratory, University of Mostaganem.The extraction was carried out according to the previous method (Sujith et al., 2011). A determined quantity of crushed plant material (root, leaf) is mixed with 100 ml of methanol. The mixture was heated at 60°C using water bath for 20 min and then filtered. Three repetitions are carried out for the same plant material to exhaust the active principles. The three filtrates were combined and the solvent was removed using a rotavapor at 40°C.
 
LC-MS/MS Analysis of U. dioica methanol extract
 
The LC-MS/MS analysis of U. dioica (nettle) methanol extract uses a UHPLC Nexera system coupled with an 8040 triple quadrupole mass spectrometer. The extract is filtered and analyzed through a C18 column with a gradient mobile phase containing water, ammonium formate, formic acid and methanol. Mass spectrometry utilizes ESI in both positive and negative modes, with MRM for quantification. The method is validated for linearity, accuracy, precision and detection limits. It successfully profiles up to 27 phytochemicals, demonstrating the plant’s medicinal and nutritional value.
 
Insecticide activity
 
The bioassay was conducted according to the direct contact method described by (Nasir et al., 2017), in which insects were directly exposed to the tested extracts. The dilutions retained for the leaf extracts are four doses, namely 10%, 20%, 30% and 40% and the same for the roots (10%, 20%, 25% and 30%). The insecticide in-vitro tests carried out with regard to the two animal species under temperature conditions of 21 ± 3°C, a relative humidity of 58±9% and a photoperiod of 14:10. For the species T. absoluta, healthy tomato leaves were fixed on absorbent paper discs soaked in mineral water in Petri dishes on which were placed three larvae, the latter must be ventilated to avoid asphyxiation larvae tested. The lids of the boxes have been made in such a way as to allow ventilation by the presence of a fine mesh tulle. Using a sprayer, our extract at each dilution is sprayed on the T. absoluta larvae. The same procedure was followed for the toxicity test against H. pruni, where the healthy tomato leaves were replaced by healthy peach leaves and on which five adults of H. pruni were deposited. The leaves are changed every two days to eliminate the nutritional factor in the mortality of the individuals tested. Control tests were applied to consolidate our results, two types were retained, one positive with the use of 10% acetone and the second just with distilled water (negative control). To do this, the same number of T. absoluta larvae and H. pruni adults were placed in the control.
 
Statistic study
 
The statistical analysis was carried out using the MINITAB® 19 statistical software. This software was used to analyze the mortality rates with ANOVA (α=0.05) and the Tukey and Fisher test used for the comparison of the variances, the differences were considered significant at P<0.05.

Analysis and determination of phenolic compounds by LC-MS/MS
 
The analysis of the phenolic profile of U. dioica, conducted using LC-MS/MS, identified 22 compounds in the leaves (Fig 1), primarily phenolic acids such as gallic acid, syringic acid and p-coumaric acid, as well as 27 compounds in the roots (Fig 2), including 4-hydroxybenzoic acid. These compounds, particularly gallic acid and phloroglucinol, are recognized for their anti-mosquito activity (Desmarchelier and Fukuto, 1974). 4-Hydroxybenzoic acid exhibits notable insecticidal properties (Safarova, 2022), while resorcinol is used in cosmetic and pharmaceutical applications (Sowmya, 2021). Ferulic acid, which is widely present in plant cell walls, is also known for its insecticidal activity (Zhang et al., 2021). Additionally, p-coumaric acid has demonstrated effectiveness against Triboliumcastaneum (Abdelkhalek et al., 2020). Extracts of nettle have been evaluated for their potential in biological insect control (González-Macedo et al., 2021).




 
Insecticidal activity
 
This research investigated the insecticidal effects of phenolic extracts from U. dioica on T. absoluta larvae at a temperature of 21±3°C, which is conducive to larval development (Boualem et al., 2012). The leaf extracts demonstrated varying mortality rates on L1 larvae after 24 hourswith 44.4% mortality at 10%, 55.5% at 20%, 33.3% at 30% and 77.8% at 40%, while the control showed 0% mortality. For L4 larvae, the 20% dose resulted in 66.7% mortality, while the other doses (10%, 30% and 40%) caused 22.2% mortality (Fig 3). The root extracts exhibited a strong insecticidal effect, achieving up to 100% mortality by the second day at doses of 25% and 30%. For L4 larvae, doses of 10% and 30% showed 65% and 79% mortality on the first day, reaching 100% by the fourth day. The control group showed increasing mortality, reaching 100% by day 8 (Fig 4).




       
The study evaluated the insecticidal effects of U. dioica leaf extract on mealy aphid adults, revealing significantly higher mortality rates compared to the control. At a 10% concentration, the mortality rate reached 66.7% after 24 hours and 100% by the third day. Higher doses (20%, 30% and 40%) resulted in mortality rates of 80%, 86.7% and 100%, respectively, while the control group showed only 13.3% mortality after 72 hours. Additionally, the root extract demonstrated a strong insecticidal effect, with 100% mortality in H. pruni adults at a 30% dose after 24 hours. No mortality was observed in the positive and negative controls within 48 hours. Overall, mortality rates were directly related to the concentration of the extract and the duration of exposure (Fig 5).


 
Estimation of LD₅₀
 
(Morris-Schaffer and McCoy, 2020) defined the LD₅₀ as the dose of a toxic compound that causes 50% mortality in a population of test animals. According to (Benazzedine, 2010), the effectiveness of a toxic product is measured by its DL50 and DL90 which represent the quantities of toxic substance resulting in the death of 50% and 90% of individuals from the same batch respectively which can be deduced from the linear regression equation of the corrected mortality curve (Fig 6 and 7).




       
The research demonstrated that methanolic extracts of U. dioica had a larvicidal effect on T. absoluta larvae, with LD90 values of 476240 ppm for leaves and 285769 ppm for roots. Comparatively, extracts from other plants, such as Annonas quamosa, showed a mortality rate of 75.1% against T. absoluta (Prasanna Kumar et al., 2020). The U. dioica extracts exhibited LD50 values of 17.54% for leaves and 13.19% for roots, indicating their potential as biopesticides.While nettle extracts showed no insecticidal effect on certain aphid species, they did exhibit repellent properties and toxicity against others, such as Callaphisjuglandis. Nettle leaf extract achieved 100% mortality in tobacco aphids at a concentration of 15 mL/L after 48 hours. Other studies indicated that the ethanol extract of Artemisia absinthium had a mortality rate of 75.64% against H. pruni, while Prunus apricot kernel showed 66.66% mortality.Field trials demonstrated that nettle purine extract has repellent activity against H. pruni and P. juglandi, suggesting species-dependent effectiveness (Toffolatti et al., 2023). Overall, the findings underscore the potential of U. dioica and other plant extracts as biopesticides, contributing to integrated pest management strategies in agriculture. The research emphasizes the importance of exploring natural alternatives to chemical pesticides for sustainable agricultural practices.

Chemical control, although commonly used, leads to numerous negative consequences, which has resulted in a growing interest in natural products. This preliminary study aims to explore bioactive molecules of agronomic and phytosanitary interest by testing the insecticidal activity of the methanolic extract of leaves and roots of U. dioica against the larvae of the tomato leaf miner T. absoluta and the adult mealybugs of plums H. pruni. These insects cause significant damage and can transmit diseases to host plants. U. dioica proves to be a promising plant, having shown excellent results against these two pests, with DL50 values of 17.54% and 13.19% against T. absoluta and 8.05% and 9.42% against H. pruni for the leaves and roots, respectively. U. dioica is rich in bioactive compounds that are valuable for agronomy and plant health and could help mitigate associated risks.

The present study was carried out with the support of the technical staff of the teaching laboratories of the Faculty of Science and Technology and the Faculty of Natural and Life Sciences at the Abdelhamid Ibn Badis University of Mostaganem.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.