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As DNA sequencing technology continues to rapidly improve, studies investigating the microbial communities of host organisms (i.e., microbiota) are becoming not only more popular but also more financially accessible. Across many taxa, microbiomes can have important impacts on organismal health and fitness. To evaluate the microbial community composition of a particular microbiome, microbial DNA must be successfully extracted. Fecal samples are often easy to collect and are a good source of gut microbial DNA. Additionally, interest in the avian preen gland microbiome is rapidly growing, due to the importance of preen oil for many aspects of avian life. Microbial DNA extractions from avian fecal and preen oil samples present multiple challenges, however. Here, we describe a modified PrepMan Ultra Sample Preparation Reagent microbial DNA extraction method that is less expensive than other commonly used methodologies and is highly effective for both fecal and preen oil samples collected from a broad range of avian species. We expect our method will facilitate microbial DNA extractions from multiple avian microbiome reservoirs, which have previously proved difficult and expensive. Our method therefore increases the feasibility of future studies of avian host microbiomes. [ABSTRACT FROM AUTHOR]

Insects are the most diverse form of life, and as such, they interact closely with humans, impacting our health, economy, and agriculture. Beneficial insect species contribute to pollination, biological control of pests, decomposition, and nutrient cycling. Pest species can cause damage to agricultural crops and vector diseases to humans and livestock. Insects are often exposed to toxic xenobiotics in the environment, both naturally occurring toxins like plant secondary metabolites and synthetic chemicals like herbicides, fungicides, and insecticides. Because of this, insects have evolved several mechanisms of resistance to toxic xenobiotics, including sequestration, behavioral avoidance, and enzymatic degradation, and in many cases had developed symbiotic relationships with microbes that can aid in this detoxification. As research progresses, the important roles of these microbes in insect health and function have become more apparent. Bacterial symbionts that degrade plant phytotoxins allow host insects to feed on otherwise chemically defended plants. They can also confer pesticide resistance to their hosts, especially in frequently treated agricultural fields. It is important to study these interactions between insects and the toxic chemicals they are exposed to in order to further the understanding of pest insect resistance and to mitigate the negative effect of pesticides on nontarget insect species like Hymenopteran pollinators.

Objective: Sclerodermus wasps are important biocontrol agents of a class of wood borers. Bacterial symbionts influence the ecology and biology of their hosts in a variety of ways, including the formation of life-long beneficial or detrimental parasitic infections. However, only a few studies have explored the species and content of the symbionts in the Sclerodermus species. Methods: Here, a high-throughput sequencing study of the V3-V4 region of the 16S ribosomal RNA gene revealed a high level of microbial variety in four Sclerodermus waps, and their diversities and functions were also predicted. Results: The three most prevalent phyla of microorganisms in the sample were Firmicutes, Bacteroides, and Proteus. The KEEG pathways prediction results indicated that the three pathways with the highest relative abundances in the S. sichuanensis species were translation, membrane transport, and nucleotide metabolism. These pathways differed from those observed in S. guani, S. pupariae, and S. alternatusi, which exhibited carbohydrate metabolism, membrane transport, and amino acid metabolism, respectively. Bacteroides were found to be abundant in several species, whereas Wolbachia was the most abundant among S. sichuanensis, with a significant negative correlation between temperature and carriage rate. Conclusions: These results offer insights into the microbial communities associated with the bethylid wasps, which is crucial for understanding how to increase the reproductive capacity of wasps, enhance their parasitic effects, and lower cost in biocontrol. [ABSTRACT FROM AUTHOR]

The rugose spiraling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae), is an invasive pest on coconut and other horticultural crops. An indigenous nymphal parasitoid, Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae), is found to co-exist as a promising natural enemy of A. rugioperculatus. The bacterial community associated with whiteflies was reported to influence the parasitism efficiency of different parasitoids. Hence, the present investigation was carried out to test the role of the associated bacterial community of A. rugioperculatus on the parasitic efficiency of E. guadeloupae through the antibiotic-curing method. The identity of the test insects viz., A. rugioperculatus and E. guadeloupae were confirmed using the mtCOI gene before carrying out the investigation. The parasitization efficiency of E. guadeloupae was recorded on symbiotic (untreated) and antibiotic-treated A. rugioperculatus nymphal stages reared on four host plants viz., coconut, banana, sapota, and guava. The antibiotics Carbenicillin @ 100 µg ml− 1 and Ciprofloxacin @ 5 µg ml− 1 were combined and fed to A. rugioperculatus adults by parafilm feeding chamber method to eliminate the possible cultivable bacteria. The results revealed the complete elimination of cultivable bacteria in the F4 generation, and hence, the F4, F5, and F6A. rugioperculatus populations were tested for their susceptibility to parasitization by E. guadeloupae. Higher parasitism (74.70%), lower emergence rate (59.70%), and longer developmental time (21.00 days) of E. guadeloupae were observed in the antibiotic-treated population than in untreated A. rugioperculatus population of the F6 generation. Elimination of bacterial symbionts through antibiotic treatment might have suppressed the immunity and nutritional status of the whiteflies and led to more susceptibility toward parasitoid attack, poor parasitoid emergence and longer developmental time of E. guadeloupae on antibiotic-treated A. rugioperculatus. Our investigation revealed that antibiotic curing of bacterial symbionts associated with host insects had a minimal impact on the parasitic efficiency of E. guadeloupae. [ABSTRACT FROM AUTHOR]

Insects are the most diverse form of life, and as such, they interact closely with humans, impacting our health, economy, and agriculture. Beneficial insect species contribute to pollination, biological control of pests, decomposition, and nutrient cycling. Pest species can cause damage to agricultural crops and vector diseases to humans and livestock. Insects are often exposed to toxic xenobiotics in the environment, both naturally occurring toxins like plant secondary metabolites and synthetic chemicals like herbicides, fungicides, and insecticides. Because of this, insects have evolved several mechanisms of resistance to toxic xenobiotics, including sequestration, behavioral avoidance, and enzymatic degradation, and in many cases had developed symbiotic relationships with microbes that can aid in this detoxification. As research progresses, the important roles of these microbes in insect health and function have become more apparent. Bacterial symbionts that degrade plant phytotoxins allow host insects to feed on otherwise chemically defended plants. They can also confer pesticide resistance to their hosts, especially in frequently treated agricultural fields. It is important to study these interactions between insects and the toxic chemicals they are exposed to in order to further the understanding of pest insect resistance and to mitigate the negative effect of pesticides on nontarget insect species like Hymenopteran pollinators. [ABSTRACT FROM AUTHOR]

Aphids (Hemiptera: Aphididae) are small, phloem-feeding insects that exhibit remarkable adaptability and resilience to various environmental conditions, including heat stress. Recent research has shed light on the role of bacterial symbionts in influencing the heat tolerance of aphids. Additionally, an intriguing avenue of investigation has explored how aphids can acquire bacterial symbionts through a unique mechanism involving soil nematodes. In this paper, we provide an in-depth overview of the interplay between heat stress, bacterial symbionts, and soil nematodes in the context of aphid biology. In reviewing the existing literature and collating available knowledge, we highlight the mechanisms by which bacterial symbionts contribute to aphid heat stress tolerance and examine the symbiont acquisition process facilitated by soil nematodes. Furthermore, we discuss the implications of these symbiotic associations in relation to the ecology, evolution, and agricultural management of a major globally expanding pest aphid, the corn leaf aphid, Rhopalosiphum maidis (Fitch). Overall, it may be concluded that both primary and secondary bacterial endosymbionts play a significant role in aphid biology with evolutionary consequences. These include adaptations through bacterial symbionts in terms of longevity and fecundity, heat shock tolerance, and resistance to fungal pathogens and primary hymenopterous wasp parasitoids. [ABSTRACT FROM AUTHOR]

Abstract As DNA sequencing technology continues to rapidly improve, studies investigating the microbial communities of host organisms (i.e., microbiota) are becoming not only more popular but also more financially accessible. Across many taxa, microbiomes can have important impacts on organismal health and fitness. To evaluate the microbial community composition of a particular microbiome, microbial DNA must be successfully extracted. Fecal samples are often easy to collect and are a good source of gut microbial DNA. Additionally, interest in the avian preen gland microbiome is rapidly growing, due to the importance of preen oil for many aspects of avian life. Microbial DNA extractions from avian fecal and preen oil samples present multiple challenges, however. Here, we describe a modified PrepMan Ultra Sample Preparation Reagent microbial DNA extraction method that is less expensive than other commonly used methodologies and is highly effective for both fecal and preen oil samples collected from a broad range of avian species. We expect our method will facilitate microbial DNA extractions from multiple avian microbiome reservoirs, which have previously proved difficult and expensive. Our method therefore increases the feasibility of future studies of avian host microbiomes.

Simple Summary: Bacterial symbionts, especially Wolbachia, are vital in many physiological processes of insects. However, the mean infection prevalence of Wolbachia in many species of lepidopteran insects is relatively low. Here, we investigated the infection, composition, abundance, and diversity of bacterial symbionts, especially Wolbachia, associated with Spodoptera frugiperda. Our results revealed that Wolbachia was found in the ovaries and salivary glands of S. frugiperda female adults. Although the infection and abundance of Wolbachia varied between geographical populations, they all belonged to the supergroup B and were named the wFru strain, which has been considered to potentially induce cytoplasmic incompatibility. These findings may provide a foundation for developing potential biocontrol techniques for S. frugiperda. Bacterial symbionts associated with insects can be crucial in insect nutrition, metabolism, immune responses, development, and reproduction. However, the bacterial symbionts of the fall armyworm Spodoptera frugiperda remain unclear. S. frugiperda is an invasive polyphagous pest that severely damages many crops, particularly maize and wheat. Here, we investigated the infection, composition, abundance, and diversity of bacterial symbionts, especially Wolbachia, in different tissues of S. frugiperda female adults. The infection prevalence frequencies of Wolbachia in five provinces of China, namely Pu'er, Yunnan; Nanning, Guangxi; Sanya, Hainan; Yunfu, Guangdong; and Nanping, Fujian, were assessed. The results indicated that Proteobacteria, Firmicutes, and Bacteroidetes were the three most dominant bacterial phyla in S. frugiperda adults. At the genus level, the abundant microbiota, which included Enterobacter and Enterococcus, varied in abundance between tissues of S. frugiperda. Wolbachia was found in the ovaries and salivary glands of S. frugiperda adults, and was present in 33.33% of the Pu'er, Yunnan, 23.33% of the Nanning, Guangxi, and 13.33% of the Sanya, Hainan populations, but Wolbachia was absent in the Yunfu, Guangdong and Nanping, Fujian populations. Further phylogenetic analyses revealed that all of the Wolbachia strains from the different S. frugiperda populations belonged to the supergroup B and were named the wFru strain. Since there were Wolbachia strains inducing cytoplasmic incompatibility in supergroup B, these findings may provide a foundation for developing potential biocontrol techniques against S. frugiperda. [ABSTRACT FROM AUTHOR]

Simple Summary: This research sheds light on the intricate connections between Bambusa-feeding insects and their symbiotic bacteria. It represents the first comparative analysis of bacterial communities across insects from three distinct orders, all feeding on the same Bambusa species. The findings underscore substantial variations in symbiotic bacteria across samples, influenced by dietary choices, seasonal variations, and host phylogeny. While insects feeding on the same plant lineage exhibit different bacterial communities, their core functional abilities remain similar. These insights contribute to our understanding of insect–bacterial interactions, providing implications for insect biology and ecology. The health and diversity of plant-feeding insects are strictly linked to their host plants and mutualistic symbionts. However, the study of bacterial symbionts within different insects on the same plant lineage is very limited. This study aimed to investigate the bacterial diversity in insect samples that exclusively feed on Bambusa, representing three insect orders, Hemiptera, Lepidoptera, and Blattodea, each exhibiting distinct dietary preferences. The bacterial community was predominantly composed of Proteobacteria, Spirochaetota, Cyanobacteria, Firmicutes, and Bacteroidota. The study found significant variations in symbiotic organisms among three insect orders: hemipterans had Buchnera, lepidopterans had Acinetobacter, and blattodean had Treponema. Furthermore, the dietary preferences of these insects played a pivotal role in shaping the symbiotic relationship of insects. Proteobacteria are prevalent in sap feeders, Spirochaetota dominate in stem feeders, and Cyanobacteria are abundant in leaf feeders. Seasonal influences also affect bacterial symbionts in P. bambucicola, with Serratia present exclusively in winter. We also observed that the bacterial composition varies across all samples, but their core functions appear to be consistent. This highlights the complex relationship between host phylogeny and diet, with phylogeny being the primary driver, shaping adaptations to specialized diets. [ABSTRACT FROM AUTHOR]

Obligate endosymbionts have a significant impact on the physiology and ecology of their insect hosts and consequently have played an important role in their diversification and evolution. Auchenorrhyncha is a sap-feeding insect group that includes cicadas, spittlebugs, leafhoppers, treehoppers, and planthoppers, some of which are well-studied vectors of plant pathogens causing important diseases. Here, we review the obligate symbiotic systems in Auchenorrhyncha. First, we address the diversity of obligate endosymbionts, illustrating the complex scenario characterised by replacements, new acquisitions, and loss of endosymbionts along evolution. Then, we describe the mechanisms that allowed maintaining these long-term associations. Also, we attend to the functional interdependence between host and obligate endosymbionts and how insect hosts support and regulate them. Moreover, we discuss current research that considers the disruption of host-endosymbionts associations as a novel strategy to control these sap-feeding insects. Finally, we suggest directions for further studies regarding obligate mutualistic relationships as well as other symbiotic systems that could be helpful in increasing the knowledge of the complex interactions between Auchenorrhyncha and their associated microbes. [ABSTRACT FROM AUTHOR]

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood), is one of the harmful pests of vegetables and ornamental plants. The high damage caused by this pest has made it necessary to design an integrated pest management (IPM) programs based on biology and its symbiotic relationships. Since the symbionts of greenhouse whiteflies are less known so far in Iran, their diversity in different pest populations has been investigated in the upcoming research. For this purpose, sampling was done from contaminated greenhouses and fields of Isfahan province. Then, DNA extraction and polymerase chain reaction (PCR) were performed to assess the presence/absence of symbionts, sequencing of target genes, and molecular identification of the whitefly species. Also, the cotton whitefly, Bemisia tabaci (Gennadius), was used as a control in different stages. The target species was identified as T. vaporariorum based on the morphology and cytochrome oxidase one (COI) gene sequence. Examining the diversity of symbionts showed the presence of Portiera sp. and Arsenophonus sp. in all collected populations. Hamiltonella sp. and Rickettsia sp. were detected in all populations except Kholenjan and Bagh Abrisham. Cardinium sp. has been observed in the population of Yafran and Fritschea sp. was detected in the populations of Khomeini Shahr, Nasim Abad, Kholenjan, Bagh Abrisham, and Yafran, while Wolbachia was not detected in any of the populations. Considering the lack of information about the symbiotic diversity of the greenhouse whitefly and also the lack of studies in Iran, this research can be a basis for further studies in the field of symbiosis and to recognize the role of symbionts.

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood), is one of the harmful pests of vegetables and ornamental plants. The high damage caused by this pest has made it necessary to design an integrated pest management (IPM) programs based on biology and its symbiotic relationships. Since the symbionts of greenhouse whiteflies are less known so far in Iran, their diversity in different pest populations has been investigated in the upcoming research. For this purpose, sampling was done from contaminated greenhouses and fields of Isfahan province. Then, DNA extraction and polymerase chain reaction (PCR) were performed to assess the presence/absence of symbionts, sequencing of target genes, and molecular identification of the whitefly species. Also, the cotton whitefly, Bemisia tabaci (Gennadius), was used as a control in different stages. The target species was identified as T. vaporariorum based on the morphology and cytochrome oxidase one (COI) gene sequence. Examining the diversity of symbionts showed the presence of Portiera sp. and Arsenophonus sp. in all collected populations. Hamiltonella sp. and Rickettsia sp. were detected in all populations except Kholenjan and Bagh Abrisham. Cardinium sp. has been observed in the population of Yafran and Fritschea sp. was detected in the populations of Khomeini Shahr, Nasim Abad, Kholenjan, Bagh Abrisham, and Yafran, while Wolbachia was not detected in any of the populations. Considering the lack of information about the symbiotic diversity of the greenhouse whitefly and also the lack of studies in Iran, this research can be a basis for further studies in the field of symbiosis and to recognize the role of symbionts. [ABSTRACT FROM AUTHOR]

Paramecium (Ciliophora, Oligohymenophorea) is a good model to study ciliate biogeography. Extensive sampling mainly in northern hemisphere has led to 16 valid morphological species description thus far. However, a majority of hard‐to‐reach regions, including South East Asia, are underinvestigated. Our study combined traditional morphological and molecular approaches to reveal the biodiversity of Paramecium in Thailand from more than 110 samples collected in 10 provinces. Representatives of seven morphological species were identified from our collection, including the rare species, such as P. gigas and P. jenningsi. Additionally, we detected five different sibling species of the P. aurelia complex, described a new cryptic species P. hiwatashii n. sp. phylogenetically related to P. caudatum, and discovered a potentially new genetic species of the P. bursaria species complex. We also documented a variety of bacterial cytoplasmic symbionts from at least nine monoclonal cultures of Paramecium. [ABSTRACT FROM AUTHOR]

Freshwater sponges (Spongillida: Demospongiae), including more than 240 described species, are globally distributed in continental waters (except for Antarctica), where they cover both natural and artificial surfaces. However, fragmentary studies have targeted their microbiome, making it difficult to test hypotheses about sponge-microbe specificity and metabolic relationships, along with the environmental factors playing key roles in structuring the associated microbial communities. To date, particular attention has been paid to sponges (family Lubomirskiidae) that are endemic to Lake Baikal. Few other freshwater sponge species (e.g., Ephydatia spp., Eunapius spp., and Spongilla lacustris), from lakes and rivers spanning from Europe to South and North America, have been targeted for microbiological studies. Representatives of the phyla Proteobacteria, Bacteroidetes, and Actinobacteria largely predominated, and high differences were reported between the microbiome of freshwater and marine sponges. Several bacterial strains isolated from freshwater sponges can produce bioactive compounds, mainly showing antibiotic activities, with potential application in biotechnology. Understanding the roles played by sponge microbiomes in freshwater ecosystems is still in its infancy and has yet to be clarified to disentangle the ecological and evolutionary significance of these largely under-investigated microbial communities. This review was aimed at providing the main available information on the composition and biotechnological potential of prokaryotic communities associated with healthy freshwater sponges, as a neglected component of the global sponge microbiome, to stimulate researchers interested in the field. [ABSTRACT FROM AUTHOR]

Within a given species, considerable inter‐individual, spatial, and temporal variation in the composition of the host microbiome exists. In group‐living animals, social interactions homogenize microbiome composition among group members, nevertheless divergence in microbiome composition among related groups arise. Such variation can result from deterministic and stochastic processes. Stochastic changes, or ecological drift, can occur among symbionts with potential for colonizing a host and within individual hosts, and drive divergence in microbiome composition among hosts or host groups. We tested whether ecological drift associated with dispersal and foundation of new groups cause divergence in microbiome composition between natal and newly formed groups in the social spider Stegodyphus dumicola. We simulated the initiation of new groups by splitting field‐collected nests into groups of 1, 3, and 10 individuals respectively, and compared variation in microbiome composition among and within groups after 6 weeks using 16S rRNA gene sequencing. Theory predicts that ecological drift increases with decreasing group size. We found that microbiome composition among single founders was more dissimilar than among individuals kept in groups, supporting this prediction. Divergence in microbiome composition from the natal nest was mainly driven by a higher number of non‐core symbionts. This suggests that stochastic divergence in host microbiomes can arise during the process of group formation by individual founders, which could explain the existence of among‐group variation in microbiome composition in the wild. Individual founders appear to harbour higher relative abundances of non‐core symbionts compared with founders in small groups, some of which are possible pathogens. These symbionts vary in occurrence with group size, indicating that group dynamics influence various core and non‐core symbionts differently. [ABSTRACT FROM AUTHOR]

Bacterial symbionts associated with insects can be crucial in insect nutrition, metabolism, immune responses, development, and reproduction. However, the bacterial symbionts of the fall armyworm Spodoptera frugiperda remain unclear. S. frugiperda is an invasive polyphagous pest that severely damages many crops, particularly maize and wheat. Here, we investigated the infection, composition, abundance, and diversity of bacterial symbionts, especially Wolbachia, in different tissues of S. frugiperda female adults. The infection prevalence frequencies of Wolbachia in five provinces of China, namely Pu’er, Yunnan; Nanning, Guangxi; Sanya, Hainan; Yunfu, Guangdong; and Nanping, Fujian, were assessed. The results indicated that Proteobacteria, Firmicutes, and Bacteroidetes were the three most dominant bacterial phyla in S. frugiperda adults. At the genus level, the abundant microbiota, which included Enterobacter and Enterococcus, varied in abundance between tissues of S. frugiperda. Wolbachia was found in the ovaries and salivary glands of S. frugiperda adults, and was present in 33.33% of the Pu’er, Yunnan, 23.33% of the Nanning, Guangxi, and 13.33% of the Sanya, Hainan populations, but Wolbachia was absent in the Yunfu, Guangdong and Nanping, Fujian populations. Further phylogenetic analyses revealed that all of the Wolbachia strains from the different S. frugiperda populations belonged to the supergroup B and were named the wFru strain. Since there were Wolbachia strains inducing cytoplasmic incompatibility in supergroup B, these findings may provide a foundation for developing potential biocontrol techniques against S. frugiperda.

The health and diversity of plant-feeding insects are strictly linked to their host plants and mutualistic symbionts. However, the study of bacterial symbionts within different insects on the same plant lineage is very limited. This study aimed to investigate the bacterial diversity in insect samples that exclusively feed on Bambusa, representing three insect orders, Hemiptera, Lepidoptera, and Blattodea, each exhibiting distinct dietary preferences. The bacterial community was predominantly composed of Proteobacteria, Spirochaetota, Cyanobacteria, Firmicutes, and Bacteroidota. The study found significant variations in symbiotic organisms among three insect orders: hemipterans had Buchnera, lepidopterans had Acinetobacter, and blattodean had Treponema. Furthermore, the dietary preferences of these insects played a pivotal role in shaping the symbiotic relationship of insects. Proteobacteria are prevalent in sap feeders, Spirochaetota dominate in stem feeders, and Cyanobacteria are abundant in leaf feeders. Seasonal influences also affect bacterial symbionts in P. bambucicola, with Serratia present exclusively in winter. We also observed that the bacterial composition varies across all samples, but their core functions appear to be consistent. This highlights the complex relationship between host phylogeny and diet, with phylogeny being the primary driver, shaping adaptations to specialized diets.

Bacterial symbionts exhibiting co-evolutionary patterns with insect hosts play a vital role in the nutrient synthesis, metabolism, development, reproduction, and immunity of insects. The brown planthopper (BPH) has a strong ability to adapt to various environmental stresses and can develop resistance to broad-spectrum insecticides. We aimed to investigate whether gut symbionts of BPH play a major role in the detoxification of insecticides and host fitness in unfavorable environments. Nicotine-treated rice plants were exposed to BPH (early stage) and the gut microbiome of the emerging female adults were analyzed using high throughput sequencing (HTS). Nicotine administration altered the diversity and community structure of BPH symbionts with significant increases in bacterial members such as Microbacteriaceae, Comamondaceae, Enterobacteriaceae, and these changes may be associated with host survival strategies in adverse environments. Furthermore, the in-vitro study showed that four intestinal bacterial strains of BPH (Enterobacter NLB1, Bacillus cereus NL1, Ralstonia NLG26, and Delftia NLG11) could degrade nicotine when grown in a nicotine-containing medium, with the highest degradation (71%) observed in Delftia NLG11. RT-qPCR and ELISA analysis revealed an increased expression level of CYP6AY1 and P450 enzyme activities in Delftia NLG11, respectively. CYP6AY1 increased by 20% under the action of Delftia and nicotine, while P450 enzyme activity increased by 18.1%. After CYP6AY1 interference, nicotine tolerance decreased, and the mortality rate reached 76.65% on the first day and 100% on the third day. Moreover, Delftia NLG11 helped axenic BPHs to increase their survival rate when fed nicotine in the liquid-diet sac (LDS) feeding system. Compared with axenic BPHs, the survival rate improved by 25.11% on day 2% and 6.67% on day 3. These results revealed an altered gut microbiota and a cooperative relationship between Delftia NLG11 and CYP6AY1 in nicotine-treated BPH, suggesting that insects can adapt to a hostile environment by interacting with their symbionts and providing a new idea for integrated pest management strategies.

Pardosa astrigera wolf spiders are important natural enemies of insect pests in cotton fields. Genetically modified (GM) crops expressing Bacillus thuringiensis (Bt) Cry proteins - toxic to target insect pests - are increasingly cultivated for insect pest management. To evaluate the potential negative effects of Bt-GM crops on beneficial non-target organisms, we assessed the effect of the Cry1Fa protein on P. astrigera, including on its symbiotic microbial communities. No adverse effects were detected on the survival rate and body weight of P. astrigera during growth and development. However, P. astrigera adult microbiome exhibited a reduced diversity as well as a shift in the microbial community structure. The dominant bacterial phyla in P. astrigera shifted from Actinobacteria to Firmicutes after feeding on prey enriched in Cry1Fa protein. Furthermore, Bacillus became the most abundant genus in P. astrigera females, while the dominant genus (Corynebacterium_1) in P. astrigera males did not change. Both males and females exhibited lower abundances of Wolbachia after feeding on Cry1Fa-contaminated prey. Overall, consuming Cry1Fa-contaminated prey changed the microbial community in P. astrigera, with higher impact in female microbiome. These findings provide new insights for environmental safety assessments of GM crops and to understand the importance of the potential effects of GM crops on microbiota of non-target organisms of importance for biocontrol ecosystem services. [ABSTRACT FROM AUTHOR]

Freshwater sponges (Spongillida: Demospongiae), including more than 240 described species, are globally distributed in continental waters (except for Antarctica), where they cover both natural and artificial surfaces. However, fragmentary studies have targeted their microbiome, making it difficult to test hypotheses about sponge-microbe specificity and metabolic relationships, along with the environmental factors playing key roles in structuring the associated microbial communities. To date, particular attention has been paid to sponges (family Lubomirskiidae) that are endemic to Lake Baikal. Few other freshwater sponge species (e.g., Ephydatia spp., Eunapius spp., and Spongilla lacustris), from lakes and rivers spanning from Europe to South and North America, have been targeted for microbiological studies. Representatives of the phyla Proteobacteria, Bacteroidetes, and Actinobacteria largely predominated, and high differences were reported between the microbiome of freshwater and marine sponges. Several bacterial strains isolated from freshwater sponges can produce bioactive compounds, mainly showing antibiotic activities, with potential application in biotechnology. Understanding the roles played by sponge microbiomes in freshwater ecosystems is still in its infancy and has yet to be clarified to disentangle the ecological and evolutionary significance of these largely under-investigated microbial communities. This review was aimed at providing the main available information on the composition and biotechnological potential of prokaryotic communities associated with healthy freshwater sponges, as a neglected component of the global sponge microbiome, to stimulate researchers interested in the field.

Abstract Background Fungi associated with insects represent one potentially rich source for the discovery of novel metabolites. However, a comprehensive understanding of the fungal communities of Apis mellifera ligustica remains elusive. Results Here, we investigated the phylogenetic diversity and community composition of honeybee-associated fungi using combination of culture-dependent and culture-independent approaches. A total of forty-five fungi were isolated and purified from the Apis mellifera ligustica, royal jelly, and honeycomb, which belonged to four classes and eleven different genera. Furthermore, 28 bacterial 16S rRNA gene sequences were obtained by PCR from the fungal metagenome. High-throughput sequencing analyses revealed that the fungal communities were more diverse, a total of 62 fungal genera were detected in the honeybee gut by culture-independent method, whereas only 4 genera were isolated by culture-dependent method. Similarly, 247 fungal genera were detected in the honeycomb, whereas only 4 genera were isolated. In addition, we assessed the antibacterial and antioxidant activities of fungal isolates. Most fungal crude extracts obtained from the cultivation supernatant exhibited antioxidant activities. Only two fungal crude extracts displayed moderate activity against Escherichia coli and Staphylococcus aureus. Chemical analysis of Chaetomium subaffine MFFC22 led to the discovery of three known compounds, including cochliodinol (1), emodin (2), chrysophanol (3). Among them, cochliodinol (1) showed intense DPPH radical scavenging activity with the 50% inhibitory concentration (IC50) of 3.06 μg/mL, which was comparable to that of the positive ascorbic acid (IC50 = 2.25 μg/mL). Compound 2 displayed weak inhibitory activities against Micrococcus tetragenus and S. aureus. Conclusions This research provided a fundamental clue for the complex interactions among honeybees, fungi, bacterial symbionts, and the effects on the honeybee. Furthermore, the diversity of honeybee-associated fungi had great potential in finding the resource of new species and antioxidants.

Background: Fungi associated with insects represent one potentially rich source for the discovery of novel metabolites. However, a comprehensive understanding of the fungal communities of Apis mellifera ligustica remains elusive. Results: Here, we investigated the phylogenetic diversity and community composition of honeybee-associated fungi using combination of culture-dependent and culture-independent approaches. A total of forty-five fungi were isolated and purified from the Apis mellifera ligustica, royal jelly, and honeycomb, which belonged to four classes and eleven different genera. Furthermore, 28 bacterial 16S rRNA gene sequences were obtained by PCR from the fungal metagenome. High-throughput sequencing analyses revealed that the fungal communities were more diverse, a total of 62 fungal genera were detected in the honeybee gut by culture-independent method, whereas only 4 genera were isolated by culture-dependent method. Similarly, 247 fungal genera were detected in the honeycomb, whereas only 4 genera were isolated. In addition, we assessed the antibacterial and antioxidant activities of fungal isolates. Most fungal crude extracts obtained from the cultivation supernatant exhibited antioxidant activities. Only two fungal crude extracts displayed moderate activity against Escherichia coli and Staphylococcus aureus. Chemical analysis of Chaetomium subaffine MFFC22 led to the discovery of three known compounds, including cochliodinol (1), emodin (2), chrysophanol (3). Among them, cochliodinol (1) showed intense DPPH radical scavenging activity with the 50% inhibitory concentration (IC50) of 3.06 μg/mL, which was comparable to that of the positive ascorbic acid (IC50 = 2.25 μg/mL). Compound 2 displayed weak inhibitory activities against Micrococcus tetragenus and S. aureus. Conclusions: This research provided a fundamental clue for the complex interactions among honeybees, fungi, bacterial symbionts, and the effects on the honeybee. Furthermore, the diversity of honeybee-associated fungi had great potential in finding the resource of new species and antioxidants. [ABSTRACT FROM AUTHOR]

Abstract: The house fly (Musca domestica) is a vector of disease-causing bacteria because of its habit of perching and feeding on various substrates of pathogenic bacteria. His role as a disease carrier contradicts the hadith narrated by Bukhari, which is "If a fly falls into your vessel, drown it and then remove it because one of its wings carries disease and the other is the cure". This hadith indicates the presence of antimicrobial compounds produced from the body of flies. Various research reports show that the truth of this hadith is that there are antimicrobial-producing bacterial symbionts on the wings of flies (left and right) that can kill pathogenic bacteria on one of the wings or both. Antimicrobial compounds are also produced naturally in the digestive tract of flies from the larval stage to adulthood as a response to the body's defense against the presence of pathogenic bacteria in their bodies. The antimicrobial compounds are lysozyme, defensin, cecropin, diptericin, and several antimicrobial peptide compounds. This compound can also be removed mechanically through pressure (the process of immersing the fly's body in water). This shows that the process of drowning aims to extract or release antimicrobial compounds from the digestive tract of flies to neutralize pathogenic bacteria that have mixed in the liquid in specific containers. This review aims to examine various reports related to antimicrobial substances produced in flies and their evidence in this hadith. Abstrak: Lalat rumah (Musca domestica) merupakan vektor pembawa bakteri penyebab penyakit karena kebiasaan hinggap dan makan pada berbagai substrat bakteri patogen. Perannya sebagai pembawa penyakit memiliki kontradiksi dengan hadist yang diriwayatkan oleh Bukhari yaitu “Jika seekor lalat jatuh ke bejana kamu, tenggelamkanlah kemudian singkirkan, karena salah satu sayapnya membawa penyakit dan sayap lainnya adalah obatnya”. Hadist ini mengindikasikan adanya senyawa antimikroba yang dihasilkan dari tubuh lalat. Berbagai laporan penelitian menunjukkan bahwa kebenaran hadist ini yaitu pada sayap lalat (kiri dan kanan) terdapat bakteri simbion penghasil antimikrob yang mampu membunuh bakteri patogen pada salah satu sayap atau keduanya. Senyawa antimikrob juga dihasilkan secara alami dalam pencernaan lalat sejak tahap larva hingga dewasa sebagai respon pertahanan tubuh terhadap keberadaan bakteri patogen ditubuhnya. Senyawa antimikrob tersebut berupa lisozim, defensin, cecrofin, diptericin dan beberapa senyawa peptida antimikrob. Senyawa ini juga dapat dikeluarkan secara mekanik melalui tekanan (proses penenggelaman tubuh lalat dalam air). Hal ini menunjukkan bahwa proses penenggelaman lalat kedalam air bertujuan untuk mengekstrak atau mengeluarkan senyawa antimikrob dari pencernaan lalat untuk menetralisir bakteri patogen yang telah bercampur dalam cairan di wadah tertentu. Review ini bertujuan untuk mengkaji berbagai laporan terkait senyawa antimikrob yang dihasilkan pada tubuh lalat dan pembuktiannya pada hadist tersebut.

Insect–bacteria symbiont associations can be found in almost all insect orders which supply an array of physiological and ecological benefits to the host insect. Plant sap‐feeding insects, including psyllids, have developed symbiotic relationships with a variety of bacteria to compensate nitrogen‐poor diets. In this study, we determined the bacterial composition of two olive psyllid pest species, Euphyllura straminea and Euphyllura pakistanica (Hemiptera: Aphalaridae), using 16S rRNA gene sequence and qPCR analyses. Proteobacteria, including Alphaproteobacteria, Gammaproteobacteria and Betaproteobacteria, composed the primary bacterial structures of the psyllids. Alphaproteobacteria were the dominant bacterial group in E. straminea, while Gammaproteobacteria composed the main portion of the bacterial structure in E. pakistanica. The primary endosymbiont, Carsonella, was detected in both psyllids and Arsenophonus with high prevalence was the main secondary endosymbiont. Interestingly, we observed high titres of Wolbachia in E. straminea compared with E. pakistanica, which revealed a negative correlation between Wolbachia and Carsonella and Arsenophonus titres. Our results show that the limited core microbiota of olive psyllids is similar while the abundance of each bacterial symbiont can vary in different species. A possible role of Wolbachia in modulating bacterial composition in the psyllids was also suggested. There is the potential to utilize symbionts for developing pest control strategies by reducing the insect host's fitness such as targeting essential endosymbionts, transferring symbionts between species and parthenogenesis. Our results can be used as a basis for further research towards the implementation of novel strategies in symbiont‐based biological control of the olive psyllids. [ABSTRACT FROM AUTHOR]

The wood‐feeding termite Coptotermes formosanus represents a unique and impressive system for lignocellulose degradation. The highly efficient digestion of lignocellulose is achieved through symbiosis with gut symbionts like bacteria. Despite extensive research during the last three decades, diversity of bacterial symbionts residing in individual gut regions of the termite and their associated functions is still lacking. To this end, cellulose, xylan, and dye‐decolorization bacteria residing in foregut, midgut, and hindgut regions of C. formosanus were enlisted by using enrichment and culture‐dependent molecular methods. A total of 87 bacterial strains were successfully isolated from different gut regions of C. formosanus which belonged to 27 different species of 10 genera, majorly affiliated with Proteobacteria (80%) and Firmicutes (18.3%). Among the gut regions, 37.9% of the total bacterial isolates were observed in the hindgut that demonstrated predominance of cellulolytic bacteria (47.6%). The majority of the xylanolytic and dye‐decolorization bacteria (50%) were obtained from the foregut and midgut, respectively. Actinobacteria represented by Dietza sp. was observed in the hindgut only. Based on species richness, the highest diversity was observed in midgut and hindgut regions each of which harbored seven unique bacterial species. The members of Enterobacter, Klebsiella, and Pseudomonas were common among the gut regions. The lignocellulolytic activities of the selected potential bacteria signpost their assistance to the host for lignocellulose digestion. The overall results indicate that C. formosanus harbors diverse communities of lignocellulolytic bacteria in different regions of the gut system. These observations will significantly advance our understanding of the termite–bacteria symbiosis and their microbial ecology uniquely existed in different gut regions of C. formosanus, which may further shed a light on its potential values at termite‐modeled biotechnology. [ABSTRACT FROM AUTHOR]

The large bowel of monogastric animals, such as that of humans, is home to a microbial community (microbiota) composed of a diversity of mostly bacterial species. Interrelationships between the microbiota as an entity and the host are complex and lifelong and are characteristic of a symbiosis. The relationships may be disrupted in association with disease, resulting in dysbiosis. Modifications to the microbiota to correct dysbiosis require knowledge of the fundamental mechanisms by which symbionts inhabit the gut. This review aims to summarize aspects of niche fitness of bacterial species that inhabit the monogastric gut, especially of humans, and to indicate the research path by which progress can be made in exploring bacterial attributes that underpin symbiont life in the gut. [ABSTRACT FROM AUTHOR]

The diversity and health of insects that feed on plants are closely related to their mutualistic symbionts and host plants. These symbiotic partners significantly influence various metabolic activities in these insects. However, the symbiotic bacterial community of toxic plant feeders still needs further characterisation. This study aims to unravel bacterial communities associated with the different species of insect representing three insect orders: Thysanoptera, Hemiptera, and Lepidoptera, along with their predicted functional role, which exclusively feeds on latex-rich plant species Ficus microcarpa . By using 16S rRNA gene high-throughput sequencing, the analysis was able to define the major alignment of the bacterial population, primarily comprising Proteobacteria , Firmicutes , Bacteroidota , Actinobacteriota , and Acidobacteriota . Significant differences in symbiotic organisms between three insect groups were discovered by the study: hemipterans had Burkholderia and Buchnera , and lepidopterans had Acinetobacter . At the same time, Pseudomonas was detected in high abundance in both lepidopteran and thysanopteran insects. Furthermore, these symbionts exhibit consistent core functions, potentially explaining how different insects can consume the same host plant. The identified core functions of symbionts open avenues for innovative approaches in utilising these relationships to develop environment-friendly solutions for pest control, with broader implications for agriculture and environmental conservation.

Simple Summary: Hairy fungus beetle, Typhaea stercorea, is a secondary post-harvest pest of stored grains that thrives by feeding on mytoxigenic fungi. Bacterial communities residing in the alimentary canal of most insects contribute to their host's development. While there are many examples, little is known about the role of bacterial communities in the alimentary canal of T. stercorea. The objectives of this study were to (1) characterize the microbial communities residing in T. stercorea and (2) compare the microbial compositions of field-collected and laboratory-reared populations. In this study, we were able to identify bacterial communities that possess mycolytic properties and track mark changes in the microbiota profiles associated with development. The genus Pseudomonas was enriched in T. stercorea larvae compared to adults. Furthermore, field-collected T. sterocrea adults had a lower species richness than both larva and adult laboratory-reared T. sterocrea. Moreover, the gut microbial compositions of field-collected and laboratory-reared populations were vastly different. Overall, our results suggest that the environment and physiology can shift the microbial composition in the alimentary canal of T. stercorea. The gut microbiomes of symbiotic insects typically mediate essential functions lacking in their hosts. Here, we describe the composition of microbes residing in the alimentary canal of the hairy fungus beetle, Typhaea stercorea (L.), at various life stages. This beetle is a post-harvest pest of stored grains that feeds on fungi and serves as a vector of mycotoxigenic fungi. It has been reported that the bacterial communities found in most insects' alimentary canals contribute to nutrition, immune defenses, and protection from pathogens. Hence, bacterial symbionts may play a key role in the digestive system of T. stercorea. Using 16S rRNA amplicon sequencing, we examined the microbiota of T. stercorea. We found no difference in bacterial species richness between larvae and adults, but there were compositional differences across life stages (PERMANOVA:pseudo-F(8,2) = 8.22; p = 0.026). The three most abundant bacteria found in the alimentary canal of the larvae and adults included Pseudomonas (47.67% and 0.21%, respectively), an unspecified genus of the Enterobacteriaceae family (46.60 % and 90.97%, respectively), and Enterobacter (3.89% and 5.75%, respectively). Furthermore, Pseudomonas spp. are the predominant bacteria in the larval stage. Our data indicated that field-collected T. stercorea tended to have lower species richness than laboratory-reared beetles (Shannon: H = 5.72; p = 0.057). Furthermore, the microbial communities of laboratory-reared insects resembled one another, whereas field-collected adults exhibited variability (PERMANOVA:pseudo-F(10,3) = 4.41; p = 0.006). We provide evidence that the environment and physiology can shift the microbial composition in the alimentary canal of T. stercorea. [ABSTRACT FROM AUTHOR]

Birds harbor complex gut bacterial communities that may sustain their ecologies and facilitate their biological roles, distribution, and diversity. Research on gut microbiomes in wild birds is surging and it is clear that they are diverse and important – but strongly influenced by a series of environmental factors. To continue expanding our understanding of how the internal ecosystems of birds work in their natural settings, we believe the most pressing needs involve studies on the functional and evolutionary aspects of these symbioses. Here we summarize the state of the field and provide a roadmap for future studies on aspects that are pivotal to understanding the biology of avian gut microbiomes, emphasizing prospects for integrating gut microbiome work in avian conservation and host health monitoring. Recent years have seen a surge in research on the wild bird microbiomes, with >100 published nonpoultry gut-microbiome studies between 2017 and 2020. We are beginning to understand the ecological, evolutionary, and environmental factors influencing the composition, variation, and functions of individual symbionts and communities. Gut symbionts may play important roles in sustaining avian ecology and facilitate host biological roles, distribution and diversity. The taxonomic composition of avian microbiomes is highly variable, both within and between host species. They are not strongly influenced by host phylogeny but more influenced by flight-adapted gut modifications, the environment, and host diet. Capitalizing on contemporary knowledge, the avian microbiome field is ready to answer mechanistic and evolutionary questions pertaining to short- and long-term associations of these complex symbioses. [ABSTRACT FROM AUTHOR]

The majority of plant viruses are transmitted by hemipteran insects. Bacterial symbionts in hemipteran hosts have a significant impact on the host life, physiology and ecology. Recently, the involvement of bacterial symbionts in hemipteran vector-virus and vector-plant interactions has been documented. Thus, the exploitation and manipulation of bacterial symbionts have great potential for plant viral disease control. Herein, we review the studies performed on the impact of symbiotic bacteria on plant virus transmission, including insect-bacterial symbiont associations, the role of these bacterial symbionts in viral acquisition, stability and release during viral circulation in insect bodies, and in viral vertical transmission. Besides, we prospect further studies aimed to understand tripartite interactions of the virus-symbiotic microorganisms-insect vector. [ABSTRACT FROM AUTHOR]

The majority of plant viruses are transmitted by hemipteran insects. Bacterial symbionts in hemipteran hosts have a significant impact on the host life, physiology and ecology. Recently, the involvement of bacterial symbionts in hemipteran vector-virus and vector-plant interactions has been documented. Thus, the exploitation and manipulation of bacterial symbionts have great potential for plant viral disease control. Herein, we review the studies performed on the impact of symbiotic bacteria on plant virus transmission, including insect-bacterial symbiont associations, the role of these bacterial symbionts in viral acquisition, stability and release during viral circulation in insect bodies, and in viral vertical transmission. Besides, we prospect further studies aimed to understand tripartite interactions of the virus-symbiotic microorganisms-insect vector.

Objective: Sclerodermus wasps are important biocontrol agents of a class of wood borers. Bacterial symbionts influence the ecology and biology of their hosts in a variety of ways, including the formation of life-long beneficial or detrimental parasitic infections. However, only a few studies have explored the species and content of the symbionts in the Sclerodermus species., Methods: Here, a high-throughput sequencing study of the V3-V4 region of the 16S ribosomal RNA gene revealed a high level of microbial variety in four Sclerodermus waps, and their diversities and functions were also predicted., Results: The three most prevalent phyla of microorganisms in the sample were Firmicutes, Bacteroides, and Proteus. The KEEG pathways prediction results indicated that the three pathways with the highest relative abundances in the S . sichuanensis species were translation, membrane transport, and nucleotide metabolism. These pathways differed from those observed in S . guani , S . pupariae , and S . alternatusi , which exhibited carbohydrate metabolism, membrane transport, and amino acid metabolism, respectively. Bacteroides were found to be abundant in several species, whereas Wolbachia was the most abundant among S. sichuanensis , with a significant negative correlation between temperature and carriage rate., Conclusions: These results offer insights into the microbial communities associated with the bethylid wasps, which is crucial for understanding how to increase the reproductive capacity of wasps, enhance their parasitic effects, and lower cost in biocontrol., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Kang, Wang, Gong, Tang and Wei.)

Insecticide susceptibility is mainly determined by the insect host, but symbiotic bacteria are also an important affecting factor. In this study, we investigate the relationship between the structure of gut bacterial symbionts and insecticide susceptibility in Diaphorina citri , the important carrier of Candidatus Liberibacter asiaticus ( C Las), the causal agent of Huanglongbing (HLB). Our results indicated that antibiotic treatment significantly increased the susceptibility of D. citri to bifenthrin and thiamethoxam, and significantly decreased the relative abundance of Wolbachia and Profftella, enzyme activities of CarEs, and expression level of multiple CarE genes. The relative loads of Wolbachia and Profftella were positively correlated with DcitCCE13 , DcitCCE14 , DcitCCE15 , and DcitCCE16 . RNAi and prokaryotic expression revealed that DcitCCE15 is associated with bifenthrin metabolism. These results revealed that bacterial symbionts might regulate DcitCCE15 expression, which is involved in the susceptibility of D. citri to bifenthrin.

The microbes associated with sponges play important roles in the nitrogen cycle of the coral reefs ecosystem, e.g., nitrification, denitrification, and nitrogen fixation. However, the whole nitrogen-cycling network has remained incomplete in any individual sponge holobiont. In this study, 454 pyrosequencing of the 16S rRNA genes revealed that the sponge Spheciospongia vesparium from the South China Sea has a unique bacterial community (including 12 bacterial phyla), dominated particularly by the genus Shewanella (order Alteromonadales). A total of 10 functional genes, nifH, amoA, narG, napA, nirK, norB, nosZ, ureC, nrfA, and gltB, were detected in the microbiome of the sponge S. vesparium by gene-targeted analysis, revealing an almost complete nitrogen-cycling network in this sponge. Particularly, bacterial urea utilization and the whole denitrification pathway were highlighted. MEGAN analysis suggests that Proteobacteria (e.g., Shewanella) and Bacteroidetes (e.g., Bizionia) are probably involved in the nitrogen cycle in the sponge S. vesparium. [ABSTRACT FROM AUTHOR]

The microbial communities associated with marine invertebrates are considered as a prolific source of bioactive metabolites. In this study, the bacteria associated with the soft coral Sarcophyton sp. collected from the Red Sea was screened for antifouling activity to identify potential natural antifouling compounds. The extract of bacterial strain Ruegeria lacuscaerulensis KAU-MB3 associated with the soft coral showed strong antifouling activity in laboratory assays. The crude bacterial extract reduced the growth of biofilm-forming bacteria and inhibited the biofilm formation significantly. Barnacle larval settlement assay indicated a significant reduction in the settlement of larvae treated with the crude extract. The crude extract was analysed by GCMS to understand the chemical composition. GC-MS results revealed the presence of compounds such as hexadecane, octatriacontyl pentafluoropropionate, cis-Z-à-bisabolene epoxide and geranyl isovalerate. In conclusion, this study indicated that the bacteria associated with the soft corals could be used as one of the potential sources for the natural product antifoulants [ABSTRACT FROM AUTHOR]

Symbionts participate in various physiological activities of their insect hosts, including detoxification metabolism. Emerging evidence has revealed that the bacterial symbiont Arsenophonus is involved in insecticide detoxification metabolism of Nilaparvata lugens, which harbors diverse symbionts. However, it is still unknown whether other bacterial symbionts have a functional role in this process. This study showed that pretreatment with antibiotics significantly increased N. lugens susceptibility to imidacloprid, chlorpyrifos, and clothianidin, and the detoxifying enzyme activities of the cytochrome P450 enzyme (P450) and glutathione S-transferase (GST) were significantly inhibited. Notably, the P450 genes NlCYP6ER1 and NlCYP4CE1, which are related to imidacloprid metabolism, were dramatically downregulated in ciprofloxacin- and tetracycline-pretreated N. lugens, respectively. Furthermore, the expression levels of various detoxifying genes (GSTs and P450s) were significantly positively correlated with Wolbachia, Arsenophonus, Acinetobacter, and Staphylococcus. These results indicated that bacterial symbionts may affect insecticide metabolism by regulating the expression of the insect host's GST and P450 genes, and provide a foundation for further study on the mechanism of symbiont-mediated host detoxification metabolism in insect pests. [ABSTRACT FROM AUTHOR]

The gut microbiomes of symbiotic insects typically mediate essential functions lacking in their hosts. Here, we describe the composition of microbes residing in the alimentary canal of the hairy fungus beetle, Typhaea stercorea (L.), at various life stages. This beetle is a post-harvest pest of stored grains that feeds on fungi and serves as a vector of mycotoxigenic fungi. It has been reported that the bacterial communities found in most insects’ alimentary canals contribute to nutrition, immune defenses, and protection from pathogens. Hence, bacterial symbionts may play a key role in the digestive system of T. stercorea. Using 16S rRNA amplicon sequencing, we examined the microbiota of T. stercorea. We found no difference in bacterial species richness between larvae and adults, but there were compositional differences across life stages (PERMANOVA:pseudo-F(8,2) = 8.22; p = 0.026). The three most abundant bacteria found in the alimentary canal of the larvae and adults included Pseudomonas (47.67% and 0.21%, respectively), an unspecified genus of the Enterobacteriaceae family (46.60 % and 90.97%, respectively), and Enterobacter (3.89% and 5.75%, respectively). Furthermore, Pseudomonas spp. are the predominant bacteria in the larval stage. Our data indicated that field-collected T. stercorea tended to have lower species richness than laboratory-reared beetles (Shannon: H = 5.72; p = 0.057). Furthermore, the microbial communities of laboratory-reared insects resembled one another, whereas field-collected adults exhibited variability (PERMANOVA:pseudo-F(10,3) = 4.41; p = 0.006). We provide evidence that the environment and physiology can shift the microbial composition in the alimentary canal of T. stercorea.

[Display omitted] • Population of spiders and species richness in Bt cotton were high in August. • Maximum abundance was of Hylyphantes graminicola and Neoscona theisi. • Seven guilds of spiders were recorded with diverse nature of hunting crop's pests. • Topmost symbiotic bacterial genus was Wolbachia in spiders. • In grouping and similarity, noticed 5 microbial sets among 4 groups of spiders. The genetically modified cotton holding Bt proteins, is noxious to bollworms larvae but very little is known about its impact on population of non-target spiders within the field. Studies conducted with the aim to identify spiders along with their abundance, prevalence pattern, preying habit on insect pests in Bt cotton (L280, Cry2Ab4) and commonness of symbiotic bacteria in these spiders. Spiders collections were made via vial tapping/jarring, from May to end of October (2018). In total, 13,342 spiders were recorded during the entire cropping season. Least relative abundance was in May (0.28%), highest in August (30.39%) while ahead decline was observed, reached to 12% in October. The 27 species were verified, least richness was in May (3 species), high in August (19 species), later in the end, reduced to 7 species. High abundance was of Hylyphantes graminicola (68.56%) and Neoscona theisi (19.98%). Existence of H. graminicola and Pardosa astrigera observed during the whole cropping season. Presence of seven guilds among spiders had a diverse nature of hunting insect pests and on number of species existed in the crop, maximum was from direct hunting habit. Composition and community structure of microbiota varied as of spider species. Proteobacteria was the most abundant bacterial phylum and topmost genus was Wolbachia in observed spiders. Five groups of bacteria distinguished across 4 clusters of spiders depending on core community of symbiotic bacterial genera. This effort is an initial step to get knowhow about spiders in Bt cotton, which will facilitate future research studies concerning spiders. [ABSTRACT FROM AUTHOR]

Ascidians host abundant and diverse bacterial symbionts, and ascidian-associated bacteria have been shown to benefit ascidian hosts. However, these host-symbiont interactions are often overlooked in coral reef ecosystems, where ascidians frequently occur as key components. In this study, we explored the bacterial communities associated with Atriolum robustum, a common ascidian from Xisha coral reef, China, using Illumina HiSeq high-throughput sequencing of the 16S rRNA gene amplicon. A total of 1411 OTUs were identified from A. robustum, revealing a high bacterial diversity with a Shannon index of 6.26 ± 1.04. Proteobacteria (in particular Alphaproteobacteria and Gammaproteobacteria) were dominant in A. robustum, followed by Bacteroidetes and Chloroflexi. Ten OTUs comprised the core microbiome of A. robustum, matching taxa with reported capabilities for heavy metal resistance, nutrient cycling, and defense against pathogens. Predictive metabolic profiles of the bacterial community associated with A. robustum, using Tax4Fun, showed a high abundance of genes involved in carbohydrate metabolism and amino acid metabolism. A comparison of the bacterial composition and predictive functions associated with A. robustum and other reported ascidians, suggested that horizontal transmission played a key role in the formation of bacterial communities in A. robustum. It was found that A. robustum from Xisha coral reef harbored a great diversity of bacteria, and bacterial symbionts had a potential functional role in metabolism and in the immune response of their ascidian host, and so played a beneficial role in maintaining the health of the coral reef ecosystem. [ABSTRACT FROM AUTHOR]

ABSTRACT Many insect species, such as aphids, leafhoppers, planthoppers, and whiteflies harbor obligate bacterial symbionts that can be transovarially transmitted to offspring through the oocytes of female insects. Whether obligate bacterial symbionts can carry important molecules/resources to the embryos to support egg development is still unknown. Here, we show that the vitellogenin (Vg) precursor of rice leafhopper Nephotettix cincticeps is biosynthesized by the fat body, secreted into the hemolymph and subsequently cleaved into the 35- and 178-kDa subunits, whereas only the 178-kDa subunit is taken up by the leading end of oocytes in a receptor-dependent manner or moves into the posterior pole of the terminal oocyte in association with obligate bacterial symbiont “Candidatus Nasuia deltocephalinicola” (hereafter Nasuia) in a receptor-independent manner. Furthermore, the 178-kDa Vg subunit can directly interact with a surface channel molecule (porin) on the envelope of Nasuia, allowing Vg to enter bacterial cytoplasm. Thus, Vg can hitchhike the ancient oocyte entry path of Nasuia, the common obligate symbiont of leafhoppers. Knocking down a Nasuia growth-related protein expression or treatment with porin antibody strongly prevents the ability of Nasuia to carry Vgs into oocytes and impair insect egg development. Nasuia-carried Vgs provide at least 20% of the total Vgs in the developing eggs. We anticipate that the bacterial symbiont-mediated Vg uptake into oocytes to support efficient egg development may be a common pattern shared by many insects. IMPORTANCE Many insects harbor obligate bacterial symbionts that can be vertically transmitted to offspring by female insects through eggs. Here, we report that leafhopper vitellogenin (Vg) recognizes and binds a surface channel molecule (porin) on the envelope of obligate bacterial symbiont Nasuia, which potentially induces the opening of porin channels for Vg to access the cytoplasm of Nasuia. Thus, Vg can exploit bacterial symbionts as the independent carriers into the oocytes. Such Nasuia-carried Vg contents support efficient insect egg development. Thus, our findings indicate that insects have evolved strategies to exploit the symbionts for carrying additional Vgs to guarantee optimal insect reproduction.

Anthropogenic global change is increasingly raising concerns about collapses of symbiotic interactions worldwide. Therefore, understanding how climate change affects symbioses remains a challenge and demands more study. Here, we look at how simulated warming affects the social ameba Dictyostelium discoideum and its relationship with its facultative bacterial symbionts, Paraburkholderia hayleyella and Paraburkholderia agricolaris. We cured and cross‐infected ameba hosts with different symbionts. We found that warming significantly decreased D. discoideum's fitness, and we found no sign of local adaptation in two wild populations. Experimental warming had complex effects on these symbioses with responses determined by both symbiont and host. Neither of these facultative symbionts increases its hosts' thermal tolerance. The nearly obligate symbiont with a reduced genome, P. hayleyella, actually decreases D. discoideum's thermal tolerance and even causes symbiosis breakdown. Our study shows how facultative symbioses may have complex responses to global change. [ABSTRACT FROM AUTHOR]

Marine sponges host highly diverse but specific bacterial communities that provide essential functions for the sponge holobiont, including antimicrobial defense. Here, we characterized the bacterial microbiome of the marine sponge Haliclona cnidata that has been in culture in an artificial marine aquarium system. We tested the hypotheses (1) that the long-term aquarium cultured sponge H. cnidata is tightly associated with a typical sponge bacterial microbiota and (2) that the symbiotic Bacteria sustain bioactivity under harmful environmental conditions to facilitate holobiont survival by preventing pathogen invasion. Microscopic and phylogenetic analyses of the bacterial microbiota revealed that H. cnidata represents a high microbial abundance (HMA) sponge with a temporally stable bacterial community that significantly shifts with changing aquarium conditions. A 4-week incubation experiment was performed in small closed aquarium systems with antibiotic and/or light exclusion treatments to reduce the total bacterial and photosynthetically active sponge-associated microbiota to a treatment-specific resilient community. While the holobiont was severely affected by the experimental treatment (i.e., bleaching of the sponge, reduced bacterial abundance, shifted bacterial community composition), the biological defense and bacterial community interactions (i.e., quorum sensing activity) remained intact. 16S rRNA gene amplicon sequencing revealed a resilient community of 105 bacterial taxa, which remained in the treated sponges. These 105 taxa accounted for a relative abundance of 72–83% of the bacterial sponge microbiota of non-treated sponge fragments that have been cultured under the same conditions. We conclude that a sponge-specific resilient community stays biologically active under harmful environmental conditions, facilitating the resilience of the holobiont. In H. cnidata, bacteria are located in bacteriocytes, which may have contributed to the observed phenomenon.

The phylogenetic diversity of fungi isolated from the Odontotermes formosanus was investigated by dilution-plate method, combined with morphological characteristics and 5.8S rDNA sequencing. Thirty-nine fungi were isolated and purified from O. formosanus, which were belonging to two phyla and four classes (Sordariomycetes, Dothideomycetes, Eurotiomycetes, Agaricomycetes). Furthermore, nine bacterial 16S rRNA sequences were obtained from total fungal genomic DNA. All bacterial symbionts were segmented into four genera: Bacillus, Methylobacterium, Paenibacillus, and Trabulsiella. The antimicrobial activities of all endophytic fungi extracts were tested by using the filter paper method against Escherichia coli (ATCC 8739), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538), and Canidia albicans (ATCC 10231). The results exhibited that 25 extracts (64%) exhibited antibacterial activity against at least one of the tested bacterial strains. Furthermore, the secondary metabolites 1 [5-hydroxyramulosin (1a):biatriosporin M (1b) = 2:1] from the Pleosporales sp. BYCDW4 exhibited potent antimicrobial activities against E. coli, C. albicans, B. subtilis, and S. aureus with the inhibition zone diameter (IZD) of 13.67, 14.33, 12.17, and 11.33 mm, respectively, which were comparable with those of the positive control. 1-(2,5-Dihydroxyphenyl)-3-hydroxybutan-1-one (2) from the Microdiplodia sp. BYCDW8 showed medium inhibitory activities against B. subtilis and S. aureus, with the IZD range of 8.32–9.13 mm. In conclusion, the study showed the diversity of insect symbionts could be expected to develop the resource of new species and antibiotics.

The white-backed planthopper (WBPH), Sogatella furcifera (Horváth), is a destructive pest of rice. Bacterial symbionts play an important role in insect hosts, especially hemipteran hosts. This study was designed to examine the bacterial symbionts of the WBPH using 16S rDNA high-throughput sequencing. A total of 63 and 177 operational taxonomic units (OTUs) were identified in females and males of three WBPH populations, respectively. These OTUs included bacteria of 75 genera from 11 phyla, where Wolbachia, Cardinium, and Asaia were the dominant genera, accounting for over 97.99% of all the symbiotic bacteria. Fluorescence in situ hybridization detected Wolbachia, Cardinium, and Asaia in the salivary glands, guts, testes, and eggs of the WBPH, indicating the potential for both horizontal and vertical transmission. Moreover, the infection pattern of the three dominant bacterial symbionts was detected in six WBPH populations. The frequencies of Wolbachia infection of females and Cardinium infection of both sexes were over 96.7%. Wolbachia infection of males ranged between 46.7 and 63.3%, which was significantly lower than that observed for females. Asaia infection of both sexes varied substantially among the populations. These results indicate that the complex host-symbiotic bacteria interaction is influenced by host sex and geographical origin and potentially by the transmission modes of the symbionts. [ABSTRACT FROM AUTHOR]

The phylogenetic diversity of fungi isolated from the Odontotermes formosanus was investigated by dilution-plate method, combined with morphological characteristics and 5.8S rDNA sequencing. Thirty-nine fungi were isolated and purified from O. formosanus , which were belonging to two phyla and four classes (Sordariomycetes, Dothideomycetes, Eurotiomycetes, Agaricomycetes). Furthermore, nine bacterial 16S rRNA sequences were obtained from total fungal genomic DNA. All bacterial symbionts were segmented into four genera: Bacillus , Methylobacterium , Paenibacillus , and Trabulsiella. The antimicrobial activities of all endophytic fungi extracts were tested by using the filter paper method against Escherichia coli (ATCC 8739), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538), and Canidia albicans (ATCC 10231). The results exhibited that 25 extracts (64%) exhibited antibacterial activity against at least one of the tested bacterial strains. Furthermore, the secondary metabolites 1 [5-hydroxyramulosin (1a) :biatriosporin M (1b) = 2:1] from the Pleosporales sp. BYCDW4 exhibited potent antimicrobial activities against E. coli , C. albicans , B. subtilis , and S. aureus with the inhibition zone diameter (IZD) of 13.67, 14.33, 12.17, and 11.33 mm, respectively, which were comparable with those of the positive control. 1-(2,5-Dihydroxyphenyl)-3-hydroxybutan-1-one (2) from the Microdiplodia sp. BYCDW8 showed medium inhibitory activities against B. subtilis and S. aureus , with the IZD range of 8.32–9.13 mm. In conclusion, the study showed the diversity of insect symbionts could be expected to develop the resource of new species and antibiotics. [ABSTRACT FROM AUTHOR]

Insects harbor a wide range of microbial symbionts, but their influence on host phenotypes is described in a limited number of biological models. One experimental approach to gain knowledge on the effects of symbionts to their hosts is to create insect lines with and without symbionts and examine their phenotypes. However, the success rate of symbiont elimination and introduction methods is dependent on several parameters that are scarcely tested or described. The pea aphid, Acyrthosiphon pisum Harris (Hemiptera: Aphididae), is a model insect of symbiosis studies. It harbors a primary symbiont that supplies the host with essential amino acids, and an array of secondary symbionts whose effects have been assessed by manipulating their presence/absence in the insect. Here, we describe the influence of key parameters on the success rate of symbiont manipulation using the pea aphid–secondary symbiont system. We compared two elimination methods differing in antibiotic treatment using several aphid–symbiont combinations. We also created new aphid host–symbiont combinations by secondary symbiont introduction and examined the effects of larval stage of recipient aphids on introduction success. Our study revealed that the aphid–symbiont combination has strong influence on both symbiont introduction and elimination success rates, and that the type of antibiotics and the larval stage of recipient aphids influence the elimination and introduction success rate, respectively. [ABSTRACT FROM AUTHOR]