Subterranean termites, Anacanthotermes ochraceus, are a widely distributed and mainly recognized in Saudi Arabia as agricultural pests and economically serious insects causing damage to wood structures. Because termites have a cryptic feeding habit and have developed resistance to several insecticides, the effectiveness of most synthetic insecticides against them has been diminished. This study was designed in laboratory using sawdust and sand bioassay to confirm six native entomopathogenic nematode (EPN) isolates' effectiveness including Steinernema feltiae NEM-29, S. feltiae AHN, Heterorhabditis indica NEM-19, H. indica NEM-18, H. bacteriophora NEM-26 and H. bacteriophora AHN22 against workers of A. ochraceus. Results revealed that termite worker mortality was higher in the sawdust bioassay than in sand bioassay. At both tested assay methods, S. feltiae had a significantly greater mortality rate, followed by H. indica and H. bacteriophora. The maximum mortalities (100% and 79.0%) was recorded for S. feltiae AHN at 1000 IJs/termite with lower LC50 values of 7.3 and 73.8 IJs/termites at 16 d-post exposure in sawdust and sand assay, respectively. All tested EPN strains reproduced successfully and emerged from dead A. ochraceus workers in 8-14 days with higher reproduction rate (22,193 IJs/termite) for S. feltiae AHN in sawdust bioassay. Conclusively, it has been discovered that native EPNs can control termites more successfully, presumably due to they have the ability to spread further infections via infected dead individuals and can directly interact with termite pests in the soil.

The large pine weevil (Hylobius abietis L.) is a major pest in European and Asian coniferous forests, particularly in managed plantations where clear-felling practices create ideal conditions for its population growth. Traditional management practices involving synthetic insecticides have limited efficacy in terms of reducing pest populations and pose environmental risks. This study evaluated the effectiveness of a wild entomopathogenic fungus (EPF) and the commercial entomopathogenic nematode Steinernema carpocapsae (EPN) as biological control agents (BCAs) against H. abietis in clear-felled spruce plantations in Wales and Scotland. Field trials used a randomised block design with three treatments (EPN full dose, EPF full dose and a combination of EPF+EPN at half doses each) compared to a control. Emergence trapping and destructive sampling were employed to assess treatment efficacy. All treatments significantly reduced weevil emergence, with the mixed treatment showing the greatest impact. Destructive sampling revealed strong associations between treatment type and infection outcomes in H. abietis, with a small but significant relationship between weevil developmental stages and infection types. Importantly, the treatments had no significant impact on the total abundance or taxon richness of non-target invertebrates. These findings suggest that wild EPFs alone and combined with EPNs are effective and environmentally safe alternatives to synthetic insecticides for managing H. abietis populations in managed forests.

Plant parasitic nematodes (PPNs) are microscopic organisms that inhabit soil and plant tissues causing a significant challenge for farmers around the globe leading to substantial crop damage and losses. Major concern on the indiscriminate use of chemical nematicides has led to exploitation of safe alternatives to mitigate these losses. Entomopathogenic nematodes (EPNs) Steinernema spp. and Heterorhabditis spp. and their associated symbiotic bacteria, Xenorhabdus spp. and Photorhabdus spp. have gained attention as eco-friendly biocontrol agents against insect pests and nematodes. They have the ability to kill the insects by causing septicaemia disease in host insect by production of toxins. EPNs are soil inhabiting, free-living nematodes that also combat PPNs. The secondary metabolites produced by these bacteria exhibits antimicrobial, antifungal, nematicidal, insecticidal, and even anticancer properties. This current review explores the potential of EPNs and their symbiotic bacteria as nematode management strategies by targeting different stages of PPNs resulting in decreased egg production and nematode population. The EPNs and their associated bacteria suppress PPNs by three different ways viz., repulsion, competition and antagonism. Overall, EPNs and their symbiotic bacteria offer sustainable and effective alternatives to chemical pesticides, since application of hazardous chemical pesticides are harmful to environment and human health. This review gives an overview and idea for further research and development of EPN's and their symbiotic bacteria as commercial bioproducts towards PPNs control.

Background Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is a polyphagous, holometabolous and multivoltine insect that has spread from its supposed origin in sub-Saharan Africa to regions between 45 degrees north and 45 degrees south geographic latitude. It is considered an important economic pest worldwide, due to the direct damage caused to fruit, the high cost of its management and the restriction of the export of fruit from infested countries to markets in countries exempt from infestation. If no control measures are applied against this pest, C. capitata can destroy 50% of total production or 100% in preferred hosts. Currently, chemical insecticides are commonly applied to control medflies due to their rapid and satisfactory action; however, this method has many problems, including the destruction of non-target organisms, residues on agricultural products, environmental pollution and the development of insect resistance to insecticides. These negative effects have led scientists to search for more sustainable and ecological new control methods. Recently, great attention has been given to biological control, which has become a practical option for the ecological control of pests. Among biological control, entomopathogenic nematodes (EPNs) have great potential as control agents for soil-borne pests, like C. capitata. Main body This review focuses particularly on the control of C. capitata, specifically emphasizing the use of EPNs as biological control agents and their integration into integrated pest management. It is apparent from this study that species of Steinernema sp. and Heterorhabditis sp. are highly virulent against the late instars larvae and adults of C. capitata under controlled laboratory conditions, as well as these EPNs significantly reduce the population of this pest in semi-field and field trials. The pathogenicity of entomopathogenic nematodes against C. capitata was influenced by natural physicochemical and anthropogenic factors. The most effective EPNs were found to be compatible with certain mineral, chemical and biological products with insecticidal activity, indicating that these products can be combined with EPNs in the context of integrated control. Conclusion Based on this, EPNs have a promising future as an alternative to conventional chemicals against Mediterranean fruit fly.

Background Isolation of novel species of entomopathogenic nematodes (EPNs) with biocontrol potential against important insect pests is very important for the sustainable management of economic pests damaging food crops and providing protection to the agricultural environment. This study was aimed to new indigenous EPN isolates from Egyptian agricultural soils and studies its biocontrol potential for further use in the biological control programs. Five out of 15 soil samples obtained from a farm located at the Cairo-Alexandria desert highway was positive for the presence of EPN, using the greater wax moth baiting method. Results Sequencing of the internal transcribed spacer (ITS) region of 4 of the nematode isolates suggested that they belong to the species Heterorhabditis indica. However, one isolate does not show a high similarity to any of the H. indica previously recorded in the database of the Gen Bank and hence was identified as a new Heterorhabditis species and was deposited at the National Center for Biotechnology Information (NCBI) and registered under accession no. (OP555450) under the name of Heterorhabditis alii. This new species was also registered in the ZooBank under the registration link of: LSID urn: lsid: zoobank.org: act: 306F9D57-CC30-4B8E-8B19-4F0E42B08F34. No males were found in this species. Morphological characterization using the light microscope (LM) and scanning electron microscope (SEM) confirmed the identification of this nematode as a new species of the genus Heterorhabditis. Moreover, virulence of this new species against the fall armyworm (FAW), Spodoptera frugiperda (Smith 1797) (Lepidoptera: Noctuidae) was tested in comparison with the foreign EPN species, Heterorhabditis bacteriophora (HP88) and the local Heterorhabditis indica (Mango 2 isolate) and proved to be more effective against this devastative insect pest than the two compared species. Conclusions The present study found out a new species of the EPN genus, Heterorhabditis in Egypt. Our results were confirmed by both morphological and molecular analyses. The efficacy of this new species against the FAW proved to be a potent and safe biocontrol agent that can be used in biological control programs against this invasive insect pest of corn in Egypt and other global countries.