In this study, we shed light for the first time on the usage of migratory locusts (Locusta migratoria) as an insect model to investigate the nanotoxicological influence of aluminum oxide (Al₂O₃) nanoparticles at low doses on testes, and evaluate the capacity of a whole-body extract of American cockroaches (Periplaneta americana) (PAE) to attenuate Al₂O₃ NPs-induced toxicity. Energy dispersive X-ray microanalyzer (EDX) analysis verified the bioaccumulation of Al in testicular tissues due to its liberation from Al₂O₃ NPs, implying their penetration into the blood–testis barrier. Remarkably, toxicity with Al engendered disorders of antioxidant and stress biomarkers associated with substantial DNA damage and cell apoptosis. Furthermore, histopathological and ultrastructural analyses manifested significant aberrations in the testicular tissues from the group exposed to Al₂O₃ NPs, indicating the overproduction of reactive oxygen species (ROS). Molecular docking analysis emphasized the antioxidant capacity of some compounds derived from PAE. Thus, pretreatment with PAE counteracted the detrimental effects of Al in the testes, revealing antioxidant properties and thwarting DNA impairment and cell apoptosis. Moreover, histological and ultrastructural examinations revealed no anomalies in the testes. Overall, these findings substantiate the potential applications of PAE in preventing the testicular impairment of L. migratoria and the conceivable utilization of locusts for nanotoxicology studies.

The abundance of metal pollutants in freshwater habitats poses serious threats to the survival and biodiversity of aquatic organisms and human beings. This study intends for the first time to assess the pernicious influences of heavy metals in Al Marioteya canal freshwater in Egypt, compared to Al Mansoureya canal as a reference site utilizing the creeping water bug (Ilyocoris cimicoides) as an ecotoxicological model. The elemental analysis of the water showed a significantly higher incidence of heavy metals, including cadmium (Cd), cobalt (Co), chromium (Cr), nickel (Ni), and lead (Pb), in addition to the calcium (Ca) element than the World Health Organization’s (WHO) permitted levels. The Ca element was measured in the water samples to determine whether exposure to heavy metals-induced oxidative stress engendered Ca deregulation in the midgut tissues of the creeping water bug. Remarkably, increased levels of these heavy metals were linked to an increase in chemical oxygen demand (COD) at the polluted site. Notably, the accumulation of these heavy metals in the midgut tissues resulted in a substantial reduction in antioxidant parameters, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and ascorbate peroxidase (APOX), along with a marked rise in malondialdehyde (MDA), cytochrome P450, and protein carbonyl levels. These results clearly indicate a noticeable disturbance in the antioxidant defense system due to uncontrollable reactive oxygen species (ROS). Notably, the results demonstrated that oxidative stress caused disturbances in Ca levels in the midgut tissue of I. cimicoides from polluted sites. Furthermore, the comet and flow cytometry analyses showed considerable proliferations of comet cells and apoptotic cells in midgut tissues, respectively, exhibiting prominent correlations, with pathophysiological deregulation. Interestingly, histopathological and ultrastructural examinations exposed noticeable anomalies in the midgut, Malpighian tubules, and ovarioles of I. cimicoides, emphasizing our findings. Overall, our findings emphasize the potential use of I. cimicoides as a bioindicator of heavy metal pollution in freshwater to improve sustainable water management in Egypt.

Green synthesis of nanoparticles has emerged as a significant strategy to develop effective and eco-friendly insecticide agents to combat insecticide resistance and preserve environmental integrity and biodiversity. This study was thus designed to fabricate novel green synthesized NiFe₂O₄ nanoparticles (NiFe NPs) and investigate their potential insecticidal effects for the first time using Blaps polychresta beetle as an agricultural coleopteran pest model. Therefore, we prepared NiFe NPs following the hydrothermal synthesis procedure in the presence of lemon juice. The physiochemical characteristics of NiFe NPs were investigated employing SEM, TEM, FT-IR, XRD, TGA, VSM, and UV-Vis analysis. The lowest and most effective dose of NiFe NPs against male beetles was ascertained at a concentration of 0.03 mg/g body weight, reporting 67% mortality after 48 h. To study the insecticidal impact of NiFe NPs, EDX analysis demonstrated the bioaccumulation of NiFe NPs in testicular tissues of beetles, leading to pathophysiological consequences. Precisely, the oxidative stress incited by NiFe NPs led to disturbance of the antioxidant defense system, which was defined by augmentation of lipid peroxidation and suppression of antioxidant enzymes. Furthermore, the comet assay exhibited remarkable DNA impairment, while flow cytometry analysis showed substantial cellular necrosis and apoptosis in NiFe NPs-treated beetles compared to control insects. In correlation with these findings, several aberrations in the histological and ultrastructure attributes of testicular tissues were perceived, including impaired follicular and cyst walls, deteriorated parietal cells, necrosis, and vacuolations. These results implied that NiFe NPs triggered oxidative injury in the testes, resulting in male reproductive system dysfunction. Altogether, our findings accentuate the potential application of NiFe NPs as nanopesticides, paving the way for the sustainable and cost-effective management of insect pests in agriculture.

The American cockroach, Periplaneta americana (Linnaeus, 1758) (Blattodea: Blattidae), is one of the most common pests that thrive in diverse environments and carries various pathogens, causing critical threats to public health and the ecosystem. We thus report in this study the first observation of decapitated American cockroaches as a result of infestation with scuttle fly parasitoids. Interestingly, behavioral alterations in the form of zombification-like behavior could be observed in cockroaches reared in the laboratory before being decapitated, implying that the insect targets cockroach heads. To identify this parasitoid, cockroaches’ corpora were isolated in jars, and apodous larvae were observed. Larvae developed into small coarctate pupae, and adults emerged. The scuttle flies were collected and exhibited tiny black, brown, to yellowish bodies. The fly was initially identified based on its morphological properties as a member of the order Diptera, family Phoridae. To provide further insights into the morphological attributes of the phorid species, the fly was examined using a scanning electron microscope (SEM) and then identified as Megaselia scalaris accordingly. SEM analysis revealed the distinctive structure of M. scalaris concerning the head, mouth parts, and legs. Specifically, the mouth parts include the labrum, labellum, rostrum, and maxillary palps. Although further investigations are still required to understand the complicated relationships between M. scalaris and American cockroaches, our findings provide a prominent step in the control of American cockroaches using M. scalaris as an efficient biological control agent.

Recently, there has been a critical demand for continuous investigations into environmental contamination with heavy metals to evaluate their detrimental impacts on different species inhabiting these contaminated areas. Therefore, we used Calosoma olivieri (Coleoptera, Carabidae) in the present study as a bioindicator for investigating pollution with heavy metals generated by pesticide industries in Kafr El-Zayat, Egypt. Toward this end, we probed the pathophysiological, histopathological, and ultrastructure anomalies of C. olivieri testicular tissues from the contaminated area in comparison to the clean site. Evaluation of heavy metal accumulation within testicular tissues was conducted employing energy-dispersive X-ray spectroscopy analysis. Furthermore, various biochemical parameters were measured to evaluate oxidative stress and the detoxification state of C. olivieri . Notably, significant inhibitions in antioxidant and detoxifying enzymes, including superoxide dismutase, catalase, glutathione S-transferase, glutathione peroxidase, reduced glutathione, and glutathione reductase, combined with elevated lipid peroxidation and protein carbonyl content were detected in testicular tissue of C. olivieri obtained from a polluted area due to the accumulation of multiple heavy metals. Additionally, severe structural aberrations were observed in the testicular tissues of C. olivieri obtained from the contaminated site compared to the control, including mitochondrial and nuclear destruction and deformed spermatogenic elements, along with obvious signs of tissue necrosis. Collectively, these results evinced impairment of male testicular tissues in beetles from the polluted location, which could serve as a reliable indicator of heavy-metal pollution in industrial areas.