Host Resources Research Articles

The impact of home institutions on the internationalization of emerging market SMEs: a systematic review

Purpose The purpose of this paper is to review literature on home-country institutional factors influencing the internationalization of small and medium-sized enterprises (SMEs) from emerging markets. Based on the analysis, the authors propose a research agenda to guide future studies in this field. Design/methodology/approach This paper follows a systematic procedure to review 58 selected articles on how institutional contexts in emerging economies impact SME internationalization, covering studies from 1999 to 2023. This period was chosen to capture recent research following the post-1990 market liberalization in most emerging economies, which has shaped new opportunities and challenges for SMEs expanding abroad. Findings This literature review shows that SMEs’ internationalization knowledge in emerging markets is strongly shaped by home-country institutional conditions. Key mechanisms include imprinting by home institutions and learning from domestic institutional sources, both critical yet underexplored areas in SME development. These processes offer substantial opportunities for future research into how institutional contexts influence SMEs’ global growth. Originality/value This research builds on previous studies that have emphasized firm-level and external factors such as host market appeal, consumer needs and resource availability driving SMEs’ internationalization. Focusing on home institutional factors, the authors provide a comprehensive review of academic studies and propose a future research agenda on the external institutional influences shaping emerging market SMEs’ global expansion.

LIFE CYCLE VARIATION AND HOST-PARASITE INTERACTIONS OF FOUR CONGENERIC SPECIES OF TURTLE ACANTHOCEPHALANS.

Turtle acanthocephalans in the genus Neoechinorhynchus have complex life cycles and are thought to involve an ostracod intermediate host and a turtle definitive host. For Neoechinorhynchus emydis, an additional snail paratenic host is part of its life cycle. However, how snails become infected and whether other species of Neoechinorhynchus can be found in snails remains unclear. This study was conducted to understand the survival, development, and host use of 4 species of turtle acanthocephalans (Neoechinorhynchus chrysemydis, N. emydis, Neoechinorhynchus emyditoides, and Neoechinorhynchus pseudemydis) in their intermediate, paratenic, and definitive hosts. Using eggs recovered from adult acanthocephalans from naturally infected turtle hosts in Oklahoma, experimental infections were conducted in 2 species of ostracods and 1 species of freshwater snail. Ionomes also were generated for these acanthocephalans and their turtle definitive hosts to better understand resource competition. Upon ingestion by ostracods, eggs of all 4 species of acanthocephalans hatched in both ostracod species. However, no further acanthocephalan development occurred in Cypridopsis sp. ostracods, whereas all 4 acanthocephalan species grew and developed into infective juveniles over 28-32 days in Physocypria sp. ostracods. Of the 4 species of acanthocephalans, N. emydis grew faster early in ostracods and was the only species to survive and establish in snail hosts. This finding was supported by the observation of proboscis remnants in the feces of snails that ingested ostracods infected with N. chrysemydis, N. emyditoides, and N. pseudemydis. In contrast, when snails were exposed to eggs of all 4 acanthocephalan species, eggs were passed in the feces, resulting in no infections. The overall ionomic composition of adult acanthocephalans and their turtle hosts suggested that the hosts and parasites share host resources. However, specific elemental differences indicated that turtle acanthocephalans can accumulate heavy metals at concentrations higher than those in their hosts. Results of this study support previous field observations and hypotheses that (1) Physocypria sp. ostracods serve as intermediate hosts for N. chrysemydis, N. emydis, N. emyditoides, and N. pseudemydis; (2) N. emydis uses snail paratenic hosts, but snails are a non-viable route of transmission to turtles for N. chrysemydis, N. emyditoides, and N. pseudemydis; and (3) as adults, these 4 acanthocephalan species utilize their turtle definitive hosts similarly in terms of ionomic composition. This work challenges the traditional view of the acanthocephalan life cycle and sets the stage for future hypotheses.

Genotypic variation in resource exchange, use, and production traits in the legume-rhizobia mutualism.

Mutualisms, reciprocally beneficial interactions between two or more species, are ubiquitous in nature. A common feature of mutualisms is extensive context-dependent variation in fitness outcomes. This context-dependency is hypothesized to stem from the environment's mediation of the relative costs and benefits associated with mutualisms. However, traits related to the exchange of goods and services in mutualisms have received little attention in comparison to net fitness outcomes. In this study, we quantified the contribution of host and symbiont genotypes to variation in resource exchange, use, and production traits measured in the host using the model mutualism between legumes and nitrogen-fixing rhizobia. We predicted that plant genotype × rhizobia genotype (G × G) effects would be common to resource exchange traits because resource exchange is hypothesized to be governed by both interacting partners through bargaining. On the other hand, we predicted that plant genotype effects would dominate host resource use and production traits because these traits are only indirectly related to the exchange of resources. Consistent with our prediction for resource exchange traits, but not our prediction for resource use and production traits, we found that rhizobia genotype and G × G effects were the most common sources of variation in the traits that we measured. The results of this study complement the commonly observed phenomenon of G × G effects for fitness by showing that numerous mutualism traits also exhibit G × G variation. Furthermore, our results highlight the possibility that the exchange of resources as well as how partners use and produce traded resources can influence the evolution of mutualistic interactions. Our study lays the groundwork for future work to explore the relationship between resource exchange, use and production traits and fitness (i.e., selection) to test the competing hypotheses proposed to explain the maintenance of fitness variation in mutualisms.

Exposure to fungal infection decreases eye size in the zooplankton, Daphnia

Abstract Immune responses can be energetically expensive and subject to trade-offs. Prior work on the freshwater zooplankton, Ceriodaphnia cornuta, demonstrated an association between eye size and infection, leading to questions about whether investment in eyes trades off against investment in immunity. We used the crustacean host, Daphnia dentifera, and its fungal parasite, Metschnikowia bicuspidata, to investigate the relationships between eye size, parasite resistance and infection. In the field, we found a negative correlation between size-corrected eye area (SCEA) and Metschnikowia infection, suggesting that either SCEA decreases infection (thereby indicating resistance) or that infection decreases SCEA. Controlled laboratory experiments reinforced the latter result: exposure to the fungal parasite decreased a host’s SCEA, regardless of the parasite dose or host genotype. We also uncovered significant plasticity in this trait—both host age and resource level increased SCEA. Identifying causality in physiological correlations is challenging. Our results suggest that negative associations between parasitism and energetically-expensive traits can arise through plasticity.

A Pathway for Advance Care Planning Co-Developed by Service Users and Interdisciplinary Healthcare Professionals in Older Persons Mental Health

Abstract Background Advance Care Planning (ACP) has been recognised as an effective mechanism for decision-making, maintaining autonomy, and ensuring that end-of-life care is aligned with an individual’s will and preference. However, healthcare professional's (HCPs) lack of confidence and knowledge has been cited as a barrier to practice. Furthermore, there are currently no widely accepted guidelines for ACP in health service settings (Barnett et al., 2024[1]). A key aim of the second stage of a three-stage action research study was to co-design a pathway to support ACP practice in a Mental Health Service for Older Persons. Reference [1] Barnett, M.D., Bennett-Leleux, L.J. & Guillory, L.A. (2024) End-of-life treatment preferences and ACP among older adults, Death Studies, 48:2, 95-102. Methods The pathway was developed through cooperative inquiry (CI), a collaborative research approach. The CI group involved three service users (one with dementia family carer experience), and six interdisciplinary HCPs coming together as co-subjects and co-researchers. Five in-person CI meetings were convened. Results The CI group co-developed a person-centred pathway encompassing a tiered approach to ACP, which would be a source of guidance and support for service users, family carers and HCPs. Key components include training and education for HCPs to enhance confidence and skills; a Padlet online platform to host resources for service users and family carers; and facilitated interventions based on the individual needs of service users, including potentially additional accompanying documentation to capture mental health needs. An interdisciplinary approach to facilitating ACP engagement, with social work taking a lead role was also suggested. Conclusion The pathway was identified as an effective approach to embedding ACP practice in older persons mental health, through a tiered person-centred framework catering to the needs of both service users, and the training needs of staff. The pathway is proposed as potentially adaptable to other older persons services to support ACP engagement.

Large attachment organelle mediates interaction between Nanobdellota archaeon YN1 and its host.

DPANN archaea are an enigmatic superphylum that are difficult to isolate and culture in the laboratory due to their specific culture conditions and apparent ectosymbiotic lifestyle. Here, we successfully isolated and cultivated a coculture system of a novel Nanobdellota archaeon YN1 and its host Sulfurisphaera ohwakuensis YN1HA. We characterized the coculture system by complementary methods, including metagenomics and metabolic pathway analysis, fluorescence microscopy, and high-resolution electron cryo-tomography (cryoET). We show that YN1 is deficient in essential metabolic processes and requires host resources to proliferate. CryoET imaging revealed an enormous attachment organelle present in the YN1 envelope that forms a direct interaction with the host cytoplasm, bridging the two cells. Together, our results unravel the molecular and structural basis of ectosymbiotic relationship between YN1 and YN1HA. This research broadens our understanding of DPANN biology and the versatile nature oftheir ectosymbiotic relationships.

Host-imposed control mechanisms in legume-rhizobia symbiosis.

Legumes are ecologically and economically important plants that contribute to nutrient cycling and agricultural sustainability, features tied to their intimate symbiosis with nitrogen-fixing rhizobia. Rhizobia vary dramatically in quality, ranging from highly growth-promoting to non-beneficial; therefore, legumes must optimize their symbiosis with rhizobia through host mechanisms that select for beneficial rhizobia and limit losses to non-beneficial strains. In this Perspective, we examine the considerable scientific progress made in decoding host control over rhizobia, empirically examining both molecular and cellular mechanisms and their effects on rhizobia symbiosis and its benefits. We consider pre-infection controls, which require the production and detection of precise molecular signals by the legume to attract and select for compatible rhizobia strains. We also discuss post-infection mechanisms that leverage the nodule-level and cell-level compartmentalization of symbionts to enable host control over rhizobia development and proliferation in planta. These layers of host control each contribute to legume fitness by directing host resources towards a narrowing subset of more-beneficial rhizobia.

The 'Goldilocks Grub': reproductive responses to leafroller host development in Goniozus jacintae, a parasitoid of the light brown apple moth.

Many parasitoids alter their reproductive behaviour in response to the quality of encountered hosts. They make adaptive decisions concerning whether to parasitise a potential host, the number of eggs laid on an accepted host, and the allocation of sex to their offspring. Here we present evidence that Goniozus jacintae Farrugia (Hymenoptera: Bethylidae), a gregarious ectoparasitoid of larval tortricids, adjusts its reproductive response to the size and developmental stage of larvae of the light brown apple moth (LBAM), Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae). Goniozus jacintae parasitises instars 3-6 of LBAM, but most readily parasitises the later, larger, instars. Brood sizes were bigger on larger hosts and brood sex ratios were female biased (proportion of males = 0.23) with extremely low variance (never >1 male in a brood at emergence), perhaps the most precise of all studied bethylids. Host size did not influence brood development time, which averaged 19.64 days, or the body size of male offspring. However, the size of females was positively correlated with host size and negatively correlated with brood size. The sizes of individual males and females were positively related to the average amount of host resource available to individuals within each brood, suggesting that adult body size is affected by scramble competition among feeding larvae. Average brood sizes were: 3rd instar host, 1.3 (SE ± 0.075); 4th instar, 2.8 (SE ± 0.18); 5th instar, 4.7 (SE ± 0.23); 6th instar, 5.4 (SE ± 0.28). The largest brood size observed was 8 individuals (7 females, 1 male) on the 6th instar of LBAM. These results suggest that later instars would give the highest yield to optimise mass-rearing of G. jacintae if used for augmentative biological pest control.

Involvement of bacteria in the development of fungal infections in the Colorado potato beetle.

Entomopathogenic fungi may interact with insects' symbiotic bacteria during infection. We hypothesized that topical infection with Beauveria bassiana may alter the microbiota of the Colorado potato beetle (CPB) and that these modifications may alter the course of mycoses. We used a model with two concentrations of conidia: (1) high concentration that causes rapid (acute) pathogenesis with fast mortality followed by bacterial decomposition of insects; (2) lower concentration that leads to prolonged pathogenesis ending in conidiation on cadavers. The fungal infections increased loads of enterobacteria and bacilli on the cuticle surface and in hemolymph and midgut, and the greatest increase was detected during the acute mycosis. By contrast, stronger activation of IMD and JAK-STAT signaling pathways in integuments and fat body was observed during the prolonged mycosis. Relatively stable (nonpathogenic) conditions remained in the midgut during both scenarios of mycosis with slight changes in bacterial communities, the absence of mesh and stat expression, a decrease in reactive oxygen species production, and slight induction of Toll and IMD pathways. Oral administration of antibiotic and predominant CPB bacteria (Enterobacteriaceae, Lactococcus, Pseudomonas) led to minor and mainly antagonistic effects in survival of larvae infected with B. bassiana. We believe that prolonged mycosis is necessary for successful development of the fungus because such pathogenesis allows the host to activate antibacterial reactions. Conversely, after infection with high concentrations of the fungus, the host's resources are insufficient to fully activate antibacterial defenses, and this situation makes successful development of the fungus impossible.

The influence of resource patch condition and size on social interactions, reproductive behaviors, and oviposition in a fungivorous beetle

Variation among resource patches can structure spatial patterns of social behavior. Individual preferences and requirements for heterogeneous resources can lead to differences in where behaviors take place and which kinds of individuals interact. In this study we examined whether properties of habitat patches predict presence of and interactions among wild forked fungus beetles (Bolitotherus cornutus). B. cornutus use shelf-like fruiting bodies of wood decaying fungi (brackets) as social arenas, courtship and mating sites, oviposition locations, and food sources. Brackets on a single log vary in size and condition and represent a dynamic resource as individual brackets decay over the years that they persist on a subpopulation. We found that size and condition significantly predicted how a bracket was used by B. cornutus. Both males and females were found more often on larger, living brackets. Larger brackets hosted proportionally more social interactions and mating behaviors relative to the overall visitation by individuals. The relationship between these resource properties and frequencies of behaviors was stronger for reproductive, between-sex social interactions. Live brackets also attracted more oviposition events by females, but bracket size had no effect on this behavior. Our results indicate that the dynamics of growth and aging of a critical resource can impact how social and reproductive behaviors are distributed in time and space, which in turn could affect the social structure of subpopulations.Significance statementSpecies that depend on critical host resources are often faced with a patchy landscape of resource quality. Those patches represent the infrastructure within which social behaviors take place, and can have formative effects on where, when, and how social interactions occur. We demonstrated that the size and condition of a fungal resource predicted male and female forked fungus beetle presence and behavior. Larger, living brackets hosted more beetles overall, while larger brackets in any condition hosted more social interactions and mating behaviors. Female beetles were more likely to lay eggs on living brackets, regardless of size. This study demonstrates how ecological dynamics of aging resource patches can indirectly structure social landscapes by influencing where and how individuals interact.

Digest: Resource limitation as a mechanism for constraining the evolution of virulence in malaria parasites.

The virulence of parasites is expected to reflect an evolutionary tradeoff between increasing proliferation rates that enhance transmission and host mortality which curtails transmission. However, host resource availability may also limit parasites' proliferation rate. To understand the role of resource limitation as a driver of virulence evolution, Pak et al. (2024) use a within-host model of red blood cell (RBC) invasion by Plasmodium chabaudi. They find that within-host resource consumption limits the evolution of the parasite's proliferation rate, as the depletion of RBCs during infection results in intermediate optimal virulence. These results suggest that resource limitation, rather than host mortality, may drive the evolution of virulence.

Variation in the response to antibiotics and life-history across the major Pseudomonas aeruginosa clone type (mPact) panel.

New treatment strategies are urgently needed for high-risk pathogens such as the opportunistic and often multidrug-resistant pathogen Pseudomonas aeruginosa. Here, we characterize the major P. aeruginosa clone type (mPact) panel. It consists of 20 strains with different origins that cover the major clone types of the species as well as its genomic diversity. This mPact panel shows significant variation in (i) resistance against distinct antibiotics, including several last resort antibiotics; (ii) related traits associated with the response to antibiotics; and (iii) general growth characteristics. We further developed a novel approach that integrates information on resistance, growth, virulence, and life-history characteristics, allowing us to demonstrate the presence of distinct adaptive strategies of the strains that focus either on host interaction or resource processing. In conclusion, the mPact panel provides a manageable number of representative strains for this important pathogen for further in-depth analyses of treatment options and evolutionary dynamics.

Host resources and parasite traits interact to determine the optimal combination of host parasite-mitigation strategies.

Organisms have evolved diverse strategies to manage parasite infections. Broadly, hosts may avoid infection by altering behaviour, resist infection by targeting parasites or tolerate infection by repairing associated damage. The effectiveness of a strategy depends on interactions between, for example,resource availability, parasite traits (virulence, life-history) and the host itself (nutritional status, immunopathology). To understand how these factors shape host parasite-mitigation strategies, we developed a mathematical model of within-host, parasite-immune dynamics in the context of helminth infections. The model incorporated host nutrition and resource allocation to different mechanisms of immune response: larval parasite prevention; adult parasite clearance; damage repair (tolerance). We also considered a non-immune strategy: avoidance via anorexia, reducing intake of infective stages. Resources not allocated to immune processes promoted host condition, whereas harm due to parasites and immunopathology diminished it. Maximising condition (a proxy for fitness), we determined optimal host investment for each parasite-mitigation strategy, singly and combined, across different environmental resource levels and parasite trait values. Which strategy was optimal varied with scenario. Tolerance generally performed well, especially with high resources. Success of the different resistance strategies (larval prevention or adult clearance) tracked relative virulence of larval and adult parasites: slowly maturing, highly damaging larvae favoured prevention; rapidly maturing, less harmful larvae favoured clearance. Anorexia was viable only in the short term, due to reduced host nutrition. Combined strategies always outperformed any lone strategy: these were dominated by tolerance, with some investment in resistance. Choice of parasite mitigation strategy has profound consequences for hosts, impacting their condition, survival and reproductive success. We show that the efficacy of different strategies is highly dependent on timescale, parasite traits and resource availability. Models that integrate such factors can inform the collection and interpretation of empirical data, to understand how those drivers interact to shape host immune responses in natural systems.

Divvying up the pie: Tissue nutrient content is related to its parasite load.

The nutrient content of host resources can influence the abundance of parasites within an ecosystem, but linking specific nutrients in a host to the abundance of different parasite taxa remains a challenge. Here, we work to forge this link by quantifying the relationship between the nutrient content of specific infection sites and the abundance of multiple parasite taxa within the digestive tract of largemouth bass (Micropterus salmoides) collected from the Mississippi River. To generate a mechanistic understanding of these relationships, we tested four basic predictions: (1) the nutrient content of different host tissues (infection sites) varies within and across hosts, (2) the nutrient content of parasite genera differs from that of their host tissue(s), (3) the nutrient content of parasite genera differ from one another and (4) the nutrient content of host tissues is related to the nutrient content and abundance of parasite genera. We found support for each of these predictions. We found stoichiometric differences between the digestive tissues we examined. We also found that across hosts, intestine and pyloric caeca C:N ratios increased and %N decreased with fish condition factor. Both of the actively feeding parasitic genera we measured had lower C:N ratios compared to both their host tissue and other encysted/non-reproductive genera, suggesting the potential for N limitation of these parasites in the intestines or pyloric caeca of hosts. Consistent with this possibility, we found that the total number of actively feeding parasitic worms in the pyloric caeca increased with that tissue's N:P ratio (but was not related to host condition factor). Our results suggest that parasites encounter significant variation in nutrient content within and across hosts and that this variation may influence the abundance of actively feeding parasites. This work highlights the need for additional empirical comparisons of parasite stoichiometry across tissues and individual hosts.

Ancestral TALE homeobox protein transcription factor regulates actin dynamics and cellular activities of protozoan parasite Entamoeba invadens.

Entamoeba histolytica causes invasive amoebiasis, an important neglected tropical disease with a significant global health impact. The pathogenicity and survival of E. histolytica and its reptilian equivalent, Entamoeba invadens, relies on its ability to exhibit efficient motility, evade host immune responses, and exploit host resources, all of which are governed by the actin cytoskeleton remodeling. Our study demonstrates the early origin and the regulatory role of TALE homeobox protein EiHbox1 in actin-related cellular processes. Several genes involved in different biological pathways, including actin dynamics are differentially expressed in EiHbox1 silenced cells. EiHbox1 silenced parasites showed disrupted F-actin organization and loss of cellular polarity. EiHbox1's presence in the anterior region of migrating cells further suggests its involvement in maintaining cellular polarity. Loss of polarized morphology of EiHbox1 silenced parasites leads to altered motility from fast, directionally persistent, and highly chemotactic to slow, random, and less chemotactic, which subsequently leads to defective aggregation during encystation. EiHbox1 knockdown also resulted in a significant reduction in phagocytic capacity and poor capping response. These findings highlight the importance of EiHbox1 of E. invadens in governing cellular processes crucial for their survival, pathogenicity, and evasion of the host immune system.

Nonrandom foraging and resource distributions affect the relationships between host density, contact rates and parasite transmission.

Nonrandom foraging can cause animals to aggregate in resource dense areas, increasing host density, contact rates and pathogen transmission, but when should nonrandom foraging and resource distributions also have density-independent effects? Here, we used a factorial experiment with constant resource and host densities to quantify host contact rates across seven resource distributions. We also used an agent-based model to compare pathogen transmission when host movement was based on random foraging, optimal foraging or something between those states. Nonrandom foraging strongly depressed contact rates and transmission relative to the classic random movement assumptions used in most epidemiological models. Given nonrandom foraging in the agent-based model and experiment, contact rates and transmission increased with resource aggregation and average distance to resource patches due to increased host movement in search of resources. Overall, we describe three density-independent mechanisms by which host behaviour and resource distributions alter contact rate functions and pathogen transmission.

Toxoplasma and Plasmodium associate with host Arfs during infection.

The parasites Toxoplasma gondii and Plasmodium live complex intracellular lifestyles where they must acquire essential host nutrients while avoiding recognition. Although previous work has sought to identify the specific nutrients scavenged by apicomplexans, the mechanisms by which host materials are transported to and across the parasite vacuole membrane are largely unknown. Here, we examined members of the host vesicular trafficking network to identify specific pathways subverted by T. gondii and Plasmodium berghei. Our results indicate that T. gondii selectively internalizes host Arfs, a class of proteins involved in intracellular trafficking. For P. berghei, host Arfs were restricted by the parasite's vacuole membrane, but proteins involved in vesicular trafficking were identified as essential for liver stage development. A greater exploration into how and why apicomplexans subvert host vesicular trafficking could help identify targets for host-directed therapeutics.

Examining the associations between a generalist feeder and a highly toxic host.

Understanding the often antagonistic plant-herbivore interactions and how host defenses can influence herbivore dietary breadth is an area of ongoing study in ecology and evolutionary biology. Typically, host plants/fungi that produce highly noxious chemical defenses are only fed on by specialists. We know very little about generalist species that can feed and develop on a noxious host. One such example of generalists feeding on toxic host occurs in the mushroom-feeding Drosophila found in the immigrans-tripunctata radiation. Although these species are classified as generalists, their acceptable hosts include deadly Amanita species. In this study, we used behavioral assays to assess associations between one mushroom-feeding species, Drosophila guttifera, and the deadly Amanita phalloides. We conducted feeding assays to confirm the presence of cyclopeptide toxin tolerance. We then completed host preference assays in female flies and larvae and did not find a preference for toxic mushrooms in either. Finally, we assessed the effect of competition on oviposition preference. We found that the presence of a competitor's eggs on the preferred host was associated with the flies increasing the number of eggs laid on the toxic mushrooms. Our results highlight how access to a low competition host resource may help to maintain associations between a generalist species and a highly toxic host.

A novel approach to potentiate a Unani formulation – Marham Kafoori – using mid-infrared rays

Worldwide, unani, an age-old medical system with Greek roots, is still in use. Potentiation in Unani remedies needs to be redesigned to meet the needs of newly emerging ailments, however potentiation has not yet been tried in the Unani system. In this study, we developed a safer and more cost-effective way to apply and potentiate Marham Kafoori, a Unani medication used for topical wounds, using a mid-infrared generating atomizer (MIRGA). With a 20–40% shorter treatment duration, the potentiated Unani medication was found to be more effective. Clinical dose reduction, host stress reduction, and resource and expense reductions follow. Using FTIR and NMR spectroscopy, MIRGA-induced modifications in Marham Kafoori were further examined in terms of chemical bond configurations and alterations, and the results are described in full below.

Understanding Insect-microbe Interactions for Sustainable Pest Management

Due to their enormous diversity, small body weight, flight and shorter lifecycles, insects thrive in almost all macro- and microhabitats. A plethora of microorganisms interact with insects as symbionts. Insect-microbial symbiont interaction can be either mutualistic, commensalism or pathogenic. The entry of a microbe mounts immune defenses in the insect at the local or systemic level in order to mitigate the damage inflicted. Microbes, on the other hand, synthesize various molecules/ toxins or develop various strategies to evade or counter insect defenses, allowing them to utilize the host resources for reproduction, coexistence or transmission. This review provides a comprehensive understanding of these insect-microbe interactions including bacteria, fungi and virus. Attempt has also been made to highlight the tripartite interactions between insects, microbes and plants in view of the need for sustainable pest management