The common pine sawfly, Diprion pini (Linnaeus, 1758) (Hymenoptera: Diprionidae), is a well-known defoliating pest of various pine forests almost all over the world, including Europe. It can cause damage to many pine species but usually opts for Pinus sylvestris Linnaeus and P. nigra subsp. laricio (Poiret) Maire. The prohibition of the use of chemical insecticides in forests (at least for T & uuml;rkiye) has led to the fact that other control methods have come to the fore in the control of this pest. In this respect, biological control agents, which are eco-friendly and can persist in the field over time, providing long-term control for plant protection, have an important potential in the control of D. pini. Therefore, in this study, entomopathogenic fungi were isolated from pine forest soils and identified by gene sequencing and phylogenetic analysis. Ten isolates (DP-37, DP-38, DP-45, DP-46, DP-49, DP-53, DP-54, DP-57, DP-58 and DP-63) were identified as Beauveria pseudobassiana, four isolates (DP-35, DP-41, DP-52, and DP-61) were identified as B. bassiana, and only one isolate was identified as Metarhizium robertsii (DP-15). All isolates were tested against the larvae of the pest under laboratory conditions, and the highest mortality and mycosis values (96.6% and 63.3%, respectively) were obtained from B. pseudobassiana DP-57. This isolate was also tested against the pest under outdoor conditions using different conidial concentrations. Based on probit analysis, the LC50 and LC90 values were estimated to be 1.309 x 107 and 1.21 x 1010 conidia/ml, respectively. The results showed that B. pseudobassiana DP-57 could be a good candidate in the biological control of D. pini.

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.

Hemolymph enables communication between organs in insects and ensures necessary coordination and homeostasis. Its composition can provide important information about the physiological state of an insect and can have diagnostic significance, which might be particularly important in the case of harmful insects subjected to biological control. Galleria mellonella Linnaeus 1758 (Lepidoptera: Pyralidae) is a global pest to honey bee colonies. The hemolymph of its larvae was examined after infection with the soil fungus Conidiobolus coronatus (Constantin) Batko 1964 (Entomophthorales). It was found that after one hour of contact with the fungus, the volume of the hemolymph increased while its total protein content decreased. In larvae with a high pathogen load, just before death, hemolymph volume decreased to nearly initial levels, while total protein content and synthesis (incorporation of 35S-labeled methionine) increased. The hemolymph polypeptide profile (SDS-PAGE followed by autoradiography) of infected insects was significantly different from that of healthy larvae. Hemocytes of infected larvae did not surround the fungal hyphae, although they encapsulated small foreign bodies (phase contrast microscopy). Infection had a negative effect on hemocytes, causing oenocyte and spherulocyte deformation, granulocyte degranulation, plasmatocyte vacuolization, and hemocyte disintegration. GC-MS analysis revealed the presence of 21 compounds in the hemolymph of control insects. C. coronatus infection caused the appearance of 5 fatty acids absent in healthy larvae (heptanoic, decanoic, adipic, suberic, tridecanoic), the disappearance of 4 compounds (monopalmitoylglycerol, monooleoylglycerol, monostearin, and cholesterol), and changes in the concentrations of 8 compounds. It remains an open question whether substances appearing in the hemolymph of infected insects are a product of the fungus or if they are released from the insect tissues damaged by the growing hyphae.

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.

The coconut rhinoceros beetle (CRB; Oryctes rhinoceros) is one of the most destructive insect pests of coconut and oil palms in tropical Asia and the Pacific islands. Members of a new variant, known as CRB-G (clade I), have recently spread into the Pacific islands, causing significant damage. Biopesticides containing Metarhizium spp. are the strongest candidates for inundative biological control against the emerging CRB threat. Selection of the most virulent and robust isolate may determine the impact of this control option on the pest. In this work, CRB specimens with natural fungal infection were collected in Papua New Guinea (PNG) and Solomon Islands (SI). Putative entomopathogenic fungi were isolated and identified. These new isolates and some previously obtained from other Pacific countries were molecularly identified, characterized, and tested for virulence against CRB larval populations in PNG and SI in laboratory bioassays. Of the new isolates collected, four obtained from SI were identified as Metarhizium majus (conidia length similar to 11-15 mu m), and four from PNG were identified as Metarhizium pingshaense (conidia length similar to 4-6 mu m). The most virulent isolate was M. majus AgR-F717, which caused 100 % mortality in 20-23 days against a CRB variant from the CRB-S grouping (clade II) in laboratory bioassays carried out in PNG. Isolates of M. pingshaense did not show pathogenicity against CRB larvae. M. majus AgR-F717 was also the most virulent in laboratory bioassays using the mixed SI population (from both CRB-S and CRB-G groupings) and was selected for further evaluation using artificial breeding sites. Under field conditions, this isolate demonstrated its ability to infect CRB, dispersal up to 100 m from treated artificial breeding sites, and persistence in soil for at least four months. The new isolate AgR-F717 of M. majus has demonstrated potential as an augmentative biological control agent for CRB in PNG and SI.

Insect pests are serious threats to agriculture, forestry, and human health because they damage crops and trees and spread diseases. Chemical insecticides control insect pests quickly and effectively, protecting crops. Environmental and health concerns arise from their use. Long-term exposure can cause pesticide-resistant insects, requiring stronger chemicals. Beneficial insects and wildlife may be harmed. Some chemical insecticides persist in the environment, causing long-term ecological damage. The present study was to isolate, identify, and characterize entomopathogenic fungi from the soil, evaluate their pathogenicity against major insect species, and evaluate the non-target effect on soil bioindicator species. Bioassay results show that Beauveria bassiana conidia are more pathogenic to all three species at 10 days after treatment, causing 100% mortality in Halyomorpha halys and Tenebrio molitor within 10 days. The lethal concentration showed lower LC50 values of 9.5 x 103 conidia/mL in H. halys, 2.6 x 103 conidia/mL in T. molitor, and 8.3x104 conidia/mL in P. japonica, B. bassiana treatment results showed a shortened insect life time LT50 of H. halys (6.0 days), T. molitor (5.3 days), and P. japonica (6.9 days). The present study concluded that B. bassiana fungi conidia are more efficient against three major insect pests.

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.

Soil-dwelling insect pests may cause considerable damage to crops worldwide, and their belowground lifestyle makes them hard to control. Amongst the most promising control agents for subterranean pests are soilborne entomopathogenic fungi (EPF) such as Metarhizium brunneum. Albeit EPF can be highly pathogenic to their target pest species under laboratory conditions, their efficacy in the field is often limited due to adverse environmental conditions. Here, we test for the first time if the efficacy of EPF can be improved when they are augmented with trap crops. In a field experiment, the M. brunneum strain ART2825 was combined with a trap crops mixture of six plant species and evaluated for its control effect of wireworms (Coleoptera: Elateridae). When both were combined in the main crop, potato damage was lowered on average by 42.5% and wireworm abundance by 50.8%. Single application of trap crops or EPF lowered damage/pest abundance only by 29.9%/15.89% and 34.7%/4.77%, respectively. Importantly, the strength of the synergistic pest control effect between trap crops and EPF increased disproportionately with increasing wireworm abundance. However, DNA-based gut content analysis showed that wireworms' feeding preferences were not shifting toward the trap crops. Our findings demonstrate that combining trap crops with EPF improves the efficacy of the latter and leads to a synergistic control effect which magnifies with increasing wireworm abundance. Hence, the synergistic effect of EPF and trap crops might be a promising control strategy for soil-dwelling pests in general and significantly improve our abilities to manage soil pests environmentally friendly.

Tenebrio molitor L., also known as the mealworm, is a polyphagous insect pest that infests various stored grains worldwide. Both the adult and larval stages can cause significant damage to stored grains. The present study focused on isolating entomopathogenic fungi from an infected larval cadaver under environmental conditions. Fungal pathogenicity was tested on T. molitor larvae and pupae for 12 days. Entomopathogenic fungi were identified using biotechnological methods based on their morphology and the sequence of their nuclear ribosomal internal transcribed spacer (ITS). The results of the insecticidal activity indicate that the virulence of fungi varies between the larval and pupal stages. In comparison to the larval stage, the pupal stage is highly susceptible to Metarhizium rileyi, exhibiting 100% mortality rates after 12 days (lethal concentration 50 [LC50] = 7.8 x 10(6) and lethal concentration 90 (LC90) = 2.1 x 10(13) conidia/mL), whereas larvae showed 92% mortality rates at 12 days posttreatment (LC50 = 1.0 x 10(6) and LC90 = 3.0 x 10(9) conidia/mL). The enzymatic analyses revealed a significant increase in the levels of the insect enzymes superoxide dismutase (4.76-10.5 mg(-1)) and glutathione S-transferase (0.46-6.53 mg(-1)) 3 days after exposure to M. rileyi conidia (1.5 x 10(5) conidia/mL) compared to the control group. The findings clearly show that M. rileyi is an environmentally friendly and effective microbial agent for controlling the larvae and pupae of T. molitor.

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.