Nematodes are among the most diverse but least studied organisms. The classic morphology-based identification has proved insufficient to the study of nematode identification and diversity, mainly for lack of sufficient morphological variations among closely related taxa. Different molecular methods have been used to supplement morphology-based methods and/or circumvent these problems with various degrees of success. These methods range from fingerprint to sequence analyses of DNA- and/or protein-based information. Image analyses techniques have also contributed towards this success. In this review, we highlight what each of these methods entail and provide examples where more recent advances of these techniques have been employed in nematode identification. Wherever possible, emphasis has been given to nematodes of agricultural significance. We show that these alternative methods have aided nematode identification and raised our understanding of nematode diversity and phylogeny. We discuss the pros and cons of these methods and conclude that no one method by itself provides all the answers; the choice of method depends on the question at hand, the nature of the samples, and the availability of resources.

Citrus nematode (Tylenchulus semipenetrans) is one of the dominant plant-parasitic nematodes in citrus-growing regions, resulting in an average yield loss between 10 and 30%. Tylenchulus semipenetrans is a sedentary semi-endoparasitic nematode that infects the roots of citrus trees, causing stunted growth, reduced fruit yield, and poor fruit quality; collectively this pathology and thus the disease caused is referred to as the slow decline of citrus. Despite its huge importance, the citrus nematode is regarded as a neglected parasite, and most research focuses on biological control and integrated pest management. Advancements in understanding the molecular mechanisms of other plant-parasitic nematodes, such as sedentary endoparasites with biological similarities to citrus nematodes, can be leveraged to gain deeper insights into the molecular mechanisms of citrus nematodes. In this review, we examine the biology, and integrated pest management of citrus nematodes, and explore future research directions toward understanding the role of genomics, gene-editing tools, and the molecular mechanisms of host-seeking and effectors used by other plant-parasitic nematodes to cause infection, which can serve as a foundation for future work in citrus nematode management.

The growing reliance on chemical pesticides in agriculture has raised significant concerns about their environmental and health impacts. This study investigates the potential of Indigenous entomopathogenic nematodes (EPNs), specifically Steinernema pakistanense and Heterorhabditis indica, as biological control agents for Leucinodes orbonalis, the brinjal fruit and shoot borer, a major pest in Karachi, Sindh, Pakistan. A comprehensive soil sampling was carried out across 30 locations. Molecular identification via PCR and sequencing confirmed the taxonomic classification of the isolated strains, showing high genetic similarity to known EPN species. The reproductive potential of the isolated strains varied, with Pak.S.SA.22 exhibiting the highest fecundity, averaging 91,944 offspring per larva, indicating strong biocontrol potential. Laboratory bioassays at different concentrations showed that Pak.S.SA.22 achieved 100% mortality of L. orbonalis at a concentration of 200 IJs/mL, confirming its effectiveness. Field trials further validated these findings, demonstrating up to 90% pest control efficacy over multiple application intervals, highlighting the practical applicability of this strain in field conditions. These results advocate for the inclusion of indigenous EPNs in integrated pest management (IPM) programs as a sustainable, environmentally friendly alternative to chemical pesticides, contributing to the promotion of sustainable agricultural practices.

The emergence of infectious diseases presents a significant global health, economic, and security risk. Climate change can unexpectedly lead to the spread of pathogens, vectors, or hosts into new areas, contributing to the rise of infectious diseases. Surveillance plays a crucial role in monitoring disease trends and implementing control strategies. In this study, we document the first discovery of Heterobilharzia americana, a parasitic schistosome of mammals and its intermediate hosts Galba cubensis and Galba humilis along the banks of the Colorado River in California. We conducted multiple samplings of snails from various locations in the region with a previous history of canine schistosomiasis. Nucleotide sequencing of the multiple regions of the snails’ and parasites’ DNA revealed the coexistence of G. cubensis and G. humilis, both infected with H. americana. Phylogenetic analyses further validate the presence of H. americana in California, suggesting a wider distribution than previously reported. Our findings have implications for public health, veterinary medicine, and biodiversity conservation, contributing to developing effective control strategies to prevent the spread of this emerging infectious disease.