Alternative Host Research Articles

Adaptation of Aglycosylated Monoclonal Antibodies for Improved Production in Komagataella phaffii.

Monoclonal antibodies (mAbs) are a major class of biopharmaceuticals manufactured by well-established processes using Chinese Hamster Ovary (CHO) cells. Next-generation biomanufacturing using alternative hosts like Komagataella phaffii could improve the accessibility of these medicines, address broad societal goals for sustainability, and offer financial advantages for accelerated development of new products. Antibodies produced by K. phaffii, however, may manifest unique molecular quality attributes, like host-dependent, product-related variants, that could raise potential concerns for clinical use. We demonstrate here conservative modifications to the amino acid sequence of aglycosylated antibodies based on the human IgG1 isotype that minimize product-related variations when secreted by K. phaffii. A combination of 2-3 changes of amino acids reduced variations across six different aglycosylated versions of commercial mAbs. Expression of a modified sequence of NIST mAb in both K. phaffii and CHO cells showed comparable biophysical properties and molecular variations. These results suggest a path toward the production of high-quality mAbs that could be expressed interchangeably by either yeast or mammalian cells. Improving molecular designs of proteins to enable a range of manufacturing strategies for well-characterized biopharmaceuticals could accelerate global accessibility and innovations.

CRISPR spacers acquired from plasmids primarily target backbone genes, making them valuable for predicting potential hosts and host range.

In recent years, there has been a surge in metagenomic studies focused on identifying plasmids in environmental samples. Although these studies have unearthed numerous novel plasmids, enriching our understanding of their environmental roles, a significant gap remains: the scarcity of information regarding the bacterial hosts of these newly discovered plasmids. Furthermore, even when plasmids are identified within bacterial isolates, the reported host is typically limited to the original isolate, with no insights into alternative hosts or the plasmid's potential host range. Given that plasmids depend on hosts for their existence, investigating plasmids without the knowledge of potential hosts offers only a partial perspective. This study introduces a method for identifying potential hosts and host ranges for plasmids through alignment with CRISPR spacers. To validate the method, we compared the PLSDB plasmids database with the CRISPR spacers database, yielding host predictions for 46% of the plasmids. When compared with reported hosts, our predictions achieved 84% concordance at the family level and 99% concordance at the phylum level. Moreover, the method frequently identified multiple potential hosts for a plasmid, thereby enabling predictions of alternative hosts and the host range. Notably, we found that CRISPR spacers predominantly target plasmid backbone genes while sparing functional genes, such as those linked to antibiotic resistance, aligning with our hypothesis that CRISPR spacers are acquired from plasmid-specific regions rather than insertion elements from diverse sources. Finally, we illustrate the network of connections among different bacterial taxa through plasmids, revealing potential pathways for horizontal gene transfer.IMPORTANCEPlasmids are notorious for their role in distributing antibiotic resistance genes, but they may also carry and distribute other environmentally important genes. Since plasmids are not free-living entities and rely on host bacteria for survival and propagation, predicting their hosts is essential. This study presents a method for predicting potential hosts for plasmids and offers insights into the potential paths for spreading functional genes between different bacteria. Understanding plasmid-host relationships is crucial for comprehending the ecological and clinical impact of plasmids and implications for various biological processes.

Tenebrio molitor (Coleoptera: Tenebrionidae) as an alternative host for the study of pathogenicity in Candida auris

BackgroundCandida auris, a multidrug-resistant fungal pathogen, has emerged as a significant global health threat due to its high transmission and mortality rates, especially in healthcare settings. ObjectiveThis study aimed to establish the larvae of the coleopteran Tenebrio molitor (mealworm) as an in vivo model to evaluate the virulence of different C. auris strains. MethodsT. molitor larvae were inoculated with varying doses and strains of C. auris. Mortality rates were monitored, melanization responses, and phenoloxidase activity were assessed. Histopathological analyses were conducted to observe tissue invasion by the yeast cells. Additionally, a biofilm formation test was included as a complementary analysis to determine if biofilm production would influence the virulence of the C. auris strains. ResultsA dose-dependent increase in mortality was observed, with the highest fungal load leading to the highest mortality rates. The study also revealed significant differences in virulence among the strains, with those from Kuwait and the reference strain CBS 10913 showing the highest pathogenicity. Melanization rates were significantly higher in infected larvae, indicating an active immune response. The histopathological analysis revealed the presence of C. auris cells within the tissue of T. molitor larvae. However, the biofilm formation complementary test did not show a significant difference in virulence among the different clades of C. auris. ConclusionThe T. molitor model effectively demonstrated the pathogenic potential and virulence differences of C. auris strains. Strains from Kuwait and the reference strain CBS 10913 exhibited the highest virulence, causing 100% mortality within 24 hours. The model also highlighted significant biofilm formation and melanization responses, correlating with fungal burden. This insect model provides a valuable and cost-effective tool for preliminary virulence screening of clinical yeast strains, offering insights into host-pathogen interactions and the potential for evaluating antifungal treatments in vivo.

Transmission pathways for the stem rust pathogen into Central and East Asia and the role of the alternate host, barberry

Abstract After many decades of effective control of stem rust caused by the Puccinia graminis f.sp. tritici, (hereafter Pgt) the reported emergence of race TTKSK/Ug99 of Pgt in Uganda reignited concerns about epidemics worldwide because ∼90% of world wheat cultivars had no resistance to the new race. Since it was initially detected in Uganda in 1998, Ug99 variants have now been identified in thirteen countries in Africa and the Middle East. Stem rust has been a major problem in the past, and concern is increasing about the risk of return to Central and East Asia. Whilst control programs in North America and Europe relied on the use of resistant cultivars in combination with eradication of barberry (Berberis spp.), the alternate host required for the stem rust pathogen to complete its full lifecycle, the focus in East Asia was principally on the use of resistant wheat cultivars. Here, we investigate potential airborne transmission pathways for stem rust outbreaks in the Middle East to reach East Asia using an integrated modelling framework combining estimates of fungal spore deposition from an atmospheric dispersion model, environmental suitability for spore germination, and crop calendar information. We consider the role of mountain ranges in restricting transmission pathways, and we incorporate a representation of a generic barberry species into the lifecycle. We find viable transmission pathways to East Asia from the Middle East to the north via Central Asia and to the south via South Asia and that an initial infection in the Middle East could persist in East Asia for up to three years due to the presence of the alternate host. Our results indicate the need for further assessment of barberry species distributions in East Asia and appropriate methods for targeted surveillance and mitigation strategies should stem rust incidence increase in the Middle East region.

Investigation of Viral, Bacterial and Parasitic Zoonotic Diseases in Rodents in Turkey.

Rodents are reservoir hosts for zoonotic pathogens that cause tropical diseases, many of which have been overlooked. The aim of this study was to investigate the presence of viral lymphocytic choriomeningitis and hantavirus infections, bacterial tularaemia and leptospirosis, and parasitic leishmaniasis and toxoplasmosis in rodents that are likely to carry and spread zoonotic agents, by using molecular methods. A total of 498 voles collected from 20 counties of Erzurum province. Conventional PCR was used for pathogen search. PCR-positive samples were subjected to sequence analysis. Hantavirus (4.8%, 24/498) and tularaemia (0.8%, 4/498) positivity were detected. However, no positivity was detected for other selected pathogens. Rodents, which are pathogen carriers and potential risk factors, are thought to may act as reservoirs for hantavirus and tularaemia in the study area. A preliminary study has been carried out at the point of detection of these diseases of global importance. The extent of the distribution of the infections, alternative hosts and the consequences of human exposure needs to be clarified through further studies.

Description of three new species of Kudoa Meglitsch, 1947 (Myxozoa: Multivalvulida) in commercial marine fishes from southern China, and new host records.

Multivalvulidan myxosporeans (Multivalvulida) of the genera Unicapsula Davis, 1924 and Kudoa Meglitsch, 1947 are mostly causative agents of latent and imperceptible infection in marine fishes. However, they are sometimes incriminated in causing post-mortem myoliquefaction or unsightly cyst formation in commercial fish. Despite the great commercial impacts of multivalvulidan infection, the biodiversity, host range and epidemiology of multivalvulidan species remain to be explored further, including infection of alternative annelid hosts. Therefore, this study aimed to identify multivalvulidan species and their host and/or distribution records in commercial fishes in China. Multivalvulidan infection was detected in ten commercial fish species of seven families from the South and East China Seas (Northwest Pacific Ocean) and the Eastern Central Atlantic Ocean (an imported Dagetichthys lusitanicus [de Brito Capello]). Based on morphological and molecular-genetic analyses of their small and large subunit of ribosomal RNA genes, five new host and/or geographical distribution records for five fish species are presented, and three new species in five fish species are described, namely Kudoa neoscomberomori sp. n. in Scomberomorus commerson (Lacépède); Kudoa pilosa sp. n. in Helicolenus hilgendorfi (Döderlein) (type host) and Sebastiscus tertius (Barsukov et Chen); and Kudoa tumidisporica sp. n. in Photopectoralis bindus (Valenciennes) (type host) and Nuchequula nuchalis (Temminck et Schlegel). This study provides new data on multivalvulidan diversity in the ocean ecosystem.

Exploring Natural Infection in Alternative Hosts of Corn Stunt Spiroplasma and Tracking the Temporal Dynamics of Corn Stunt Disease in the Brazilian Cerrado Biome

The corn stunt disease complex, caused by the mollicutes Spiroplasma kunkelii (Css) and the maize bushy stunt (MBS) phytoplasma, is a major phytosanitary issue for corn production in the neotropical region of Brazil. In this study, we investigated the presence of alternative hosts for S. kunkelii (Css) in the Brazilian Cerrado biome and explored the potential for asymptomatic Css infections in maize plants. To identify possible alternative hosts, we collected samples from ornamental and native plants located in Cerrado regions with a high incidence of corn stunt disease. We also monitored the disease’s progression over time and calculated the area under the disease progression curve (AUDPC). Additionally, we sampled healthy, asymptomatic maize plants growing near symptomatic ones and analyzed all the samples using qPCR to detect the pathogen. Our results showed no Css infection in the sampled alternative host species and no asymptomatic infections in the nearby maize plants. The incidence of maize stunting varied significantly among the sample years and counties. In Aparecida do Rio Negro, the infection rate was six times higher in 2020 compared to 2019, while Porto Nacional showed an 11-fold increase. During surveillance from March to July, the infection rate at the Sierra site went from less than 3% in March 2019 to 6% in July (F1,4 = 415.84; p = 0.0003). MBS infection increased significantly, while S. kunkelii remained stable below 3%. In 2020, MBS increased from 3% to more than 12%. A similar trend was observed at the Sede site, where MBS increased from 9% in 2019 to 11% in 2020. An increase in the AUDPC was observed both within individual years and between 2019 and 2020, indicating a worsening trend in disease severity. Overall, our findings reinforce the need for preventive measures in managing maize crop fields.

An integrated analysis of the Passifloraceae virome using public-domain data.

Passifloraceae is a plant family that includes several species of interest in the food, medicinal, and ornamental industries. The most relevant species are the purple and yellow varieties of P. edulis, which are among the most highly prized tropical fruits in the international markets. Unfortunately, the rapid expansion of this crop worldwide has resulted in the emergence of several viral diseases that endangered the productivity of this crop. In this work, we performed an integrated analysis of the Passifloraceae virome using public data. We investigated Pubmed and Genbank records and analyzed all the transcriptome data available for members of this plant family. This analysis resulted in the identification of six novel virus associations and six putative new viral species. We also used RNAseq to inspect virus accumulation levels and mixed infections. Using network analysis, we also examined the global distribution of Passiflora viruses and their associations with alternative hosts, which is valuable information in implementing viral disease management strategies. Our data suggest that a large diversity of viruses remains to be discovered. Finally, we used the information gathered in this work to estimate the cross-transmission risk of viruses in Colombian Passiflora fields.

Behavioral, Physiological, and Molecular Mechanisms Underlying the Adaptation of Helicoverpa armigera to the Fruits of a Marginal Host: Walnut (Juglans regia).

In northwest China, changes in cultivation patterns and the scarcity of preferred hosts have forced Helicoverpa armigera to feed on the marginal host walnut (Juglans regia). However, the mechanisms allowing this adaptation remain poorly understood. Here, we investigated the behavioral, physiological, and molecular mechanisms underlying the local adaptation of this pest to walnut fruits. The green husk and shell generally contained higher levels of phytochemicals than the kernel. Bioassays revealed that the phytochemical-rich green husk and shell were less preferred, reduced larval fitness and growth, and elevated the activity of detoxification enzymes compared to the nutrient-rich kernel, which were further supported by a larger number of upregulated detoxification genes in insects fed green husks or shells based on transcriptome sequencing. Together, these data suggest that P450 genes (LOC110371778) may be crucial to H. armigera adaptation to the phytochemicals of walnuts. Our findings provide significant insight into the adaptation of H. armigera to walnut, an alternative host of lower quality. Meanwhile, our study provides a theoretical basis for managing resistance to H. armigera larvae in walnut trees and is instrumental in developing comprehensive integrated pest management strategies for this pest in walnut orchards and other agricultural systems.

The occurrence patterns and alternative host use of the generalist parasitoid Parvilucifera infectans (Alveolata, Perkinsozoa) of marine dinoflagellates revealed by a high-frequency time series microscopic data at a temperate coastal site

Species belonging to the genus Parvilucifera (Alveolata, Perkinsozoa) are known as generalist parasitoids that can infect a variety of marine dinoflagellates and ultimately kill the host cell. Despite the accumulation of knowledge on Parvilucifera parasitoids over the last twenty years, the occurrence pattern and use of alternative hosts for persistent transmission within fluctuating natural dinoflagellate host communities have received relatively little attention. To address this, high-frequency (i.e., daily) time series protist monitoring was conducted for 411 days, from April 2020 to May 2021, at a temperate coastal site in Jinhae Bay, Republic of Korea. This site was characterized by frequent blooms of mixed dinoflagellates throughout most of the year. Nonetheless, Parvilucifera infections were detected only in the spring seasons, and its occurrence pattern was primarily governed by the presence and cell density of its primary dinoflagellate host, Akashiwo sanguinea. As long as the primary host was present at high densities (greater than 104 cells L-1), this primary host alone could support the transmission and persistence of the parasitoid. However, if the cell density of the primary host started to decline, then Parvilucifera searched for and exploited alternative hosts for its continued survival. Taken together, this study suggests that the presence and cell density of its preferred primary host species and the duration for which the density remains above the threshold level are key factors that regulate the timing of Parvilucifera occurrence and alternative host use.

Solenopsis richteri (Hymenoptera: Formicidae) alates infected with deformed wing virus display wing deformity with altered mobility.

Deformed wing virus (DWV) has long been identified as a critical pathogen affecting honeybees, contributing to colony losses through wing deformities, neurological impairments, and reduced lifespan. Since DWV also affects other pollinators, it poses a significant threat to global pollination networks. While honeybees have been the focal point of DWV studies, emerging research indicates that this RNA virus is not host-specific but rather a generalist pathogen capable of infecting a wide range of insect species, including other bee species such as bumblebees and solitary bees, as well as wasps and ants. This expands the potential impact of DWV beyond honeybees to broader ecological communities. The black imported fire ant, Solenopsis richteri, is an economically important invasive ant species. In this study, we describe deformed wing (DW) symptoms in S. richteri. DW alates were found in three of nine (33%) laboratory colonies. The symptoms ranged from severely twisted wings to a single crumpled wing tip. Additionally, numerous symptomatic alates also displayed altered mobility, ranging from an ataxic gait to an inability to walk. Viral replication of DWV was confirmed using a modified strand-specific RT-PCR. Our results suggest that S. richteri can be an alternative host for DWV, expanding our understanding of DWV as a generalist pathogen in insects. However, additional research is required to determine whether DWV is the etiological agent responsible for DW syndrome in S. richteri.

First Report of Rhizoctonia solani AG 4 HG-III Causing Stem Lesion of Watermelon in Idaho.

In July 2022, stem lesions, approximately 4 to 5 cm in length as well as leaf wilt and dark brown necrosis on stems and roots were observed in two fields in Southwest Idaho on 20 to 30% of watermelons (Citrullus lanatus). To determine the causal agent, isolations were attempted from symptomatic tissue. The surface of the affected material was disinfected with 0.6% sodium hypochlorite for 1 min and rinsed three times with sterile water. Approximately 2 mm3 sections of tissue were plated on water agar amended with 0.02% penicillin and 0.08% streptomycin and incubated at room temperature for 7 days. Fungal colonies were tentatively identified as Rhizoctonia from right-angle branching and septate hyphal structures, slight constriction and septum near the branch base, and the production of 1 to 2 mm white to light brown irregularly shaped sclerotia. Single hyphal tips were transferred to potato dextrose agar (PDA) and grown at room temperature. Approximately ten isolates from each field with a consistent macromorphology were observed. These isolates had light brown mycelia, produced sclerotia at ambient temperature with no exposure to continuous light, and a representative isolate, designated D22-110 was selected for sequencing and pathogenicity testing. For isolate D22-110, mycelia were removed with a scalpel after 7 days of growth, for DNA extraction and sequencing of the rDNA internal transcribed spacer (ITS) region as previously described (White et al., 1990). A 726 bp product was generated and the sequence was submitted to GenBank (Accession No. OQ794049). NCBI-BLAST indicated this sequence was 99% identical (631 of 634 bp and 632 of 634 bp identical) with known reference isolates previously identified as R. solani AG 4 HG-III (Accession No. AF354075 and AF354076, respectively) from a phylogenetic study (Gonzalez et al., 2001). Pathogenicity testing was performed twice on two-week-old seedlings of watermelon cultivars Endless Summer and Wingman in greenhouse conditions (29oC, 12 h daylight). Two disks (3 mm diam) from 7-day-old plates of PDA were placed around each seedling at the root and stem convergence point. Ten seedlings were mock-inoculated with sterile PDA plugs as a control. Approximately 35% damping-off incidence was observed on inoculated seedlings six days post-inoculation, while control seedlings remained healthy. At 20 days post-inoculation, 20 (first trial) and 34 seedlings (second trial) were assessed for visible stem and root lesions. Incidence of stem lesions occurred on 90% of seedlings, with 80% of seedlings possessing lesions greater than 10 mm in diameter. Seedlings without R. solani inoculation were free of stem and root lesions. R. solani was re-isolated from symptomatic tissue, with 40% frequency of isolation, identified by right-angle branching of the hyphae thus confirming Koch's postulates. R. solani AG 4 has been reported in watermelon in the US since 1994 (Hall and Summer, 1994) but the AG 4 subgroup was not reported. AG 4 HG-III was reported in melon seedlings causing damping-off in Kyrgyzstan (Erper et al. 2016). In other hosts, AG 4 HG-III was found in potatoes in South Africa (Muzhinji et al., 2014), buckwheat and foxtail millet in China (Zhou et al., 2015; Hao et al., 2023), broccoli and spinach (Kuramae et al., 2003) and turnip green (Sekiguchi et al., 2015). To the best of our knowledge, this is the first report of R. solani AG 4 HG-III causing disease in watermelon in Idaho. Given the the rate of disease incidence observed in the field, growers should consider avoiding planting alternative host crops to minimize inoculum buildup.

Influence of Host Lattice Ions on the Dynamics of Transient Multiband Upconversion in Yb-Er Codoped NaLnF4 and LiLnF4 Microcrystals (Ln: Y, Lu, Gd).

Inorganic host matrices provide a tunable luminescence environment for lanthanide ions, allowing for the modulation of upconversion luminescence (UCL) properties. AREF4 (A = alkali metal, RE = rare earth) have a low phonon energy and a high optical damage threshold, making them widely used as the host matrix for UCL materials. However, the impact mechanism of alkali metal ions and lanthanide lattice ions on transient UCL dynamics in AREF4 remains unclear. This study utilized a high-power nanosecond-pulsed laser at 976 nm to excite Yb-Er codoped NaLnF4 and LiLnF4 (Ln: Y, Lu, and Gd) microcrystals (MCs). All samples exhibit multiband emission, and the transient UC dynamics are discussed in detail. Compared with LiLnF4, NaLnF4 has higher UC efficiency and red to green (R/G) ratio. Lanthanide ions (Y, Lu, and Gd) affect the energy transfer (ET) distance in Yb-Er codoped systems, thereby altering UC efficiency and the R/G ratio. The energy level coupling between Gd3+ and Er3+ prolongs the duration of the UC emission. Specifically, the red emission lifetime of NaGdF4 is five times longer than that of NaYF4. Our research contributes to exploring excellent alternative host matrices for NaYF4 in the fields of rapid-response optoelectronic devices, micro-nano lasers, and stimulated emission depletion (STED) microscopy.

Viral adaptations to alternative hosts in the honey bee pathogen Paenibacillus larvae.

Bacteriophages (phages) that are intended to be used to treat bacterial infections are often improved using genetic engineering or experimental evolution. A protocol called "Appelmans" utilizes evolution in microtiter plates to promote the evolution of phages that can infect nonpermissive hosts. We tested a modification of the Appelmans protocol using the honey bee pathogen, Paenibacillus larvae. Three phages evolved together on four P. larvae strains following the standard Appelmans protocol and a modified version to ensure high phage diversity throughout ten rounds of passaging. The host range of 360 plaques were characterized and six new phage lysis patterns were identified. These new phage lysis patterns included plaque formation on previously nonpermissive, phage-resistant isolates that were used to identify phage types. The modified protocol did not drastically change the rate or number of new phage types observed but did prevent the phage population from being dominated by one phage that tended to rapidly raise in frequency. These findings showed how a minor modification of the Appelmans protocol influenced the development of phages for phage therapy. The method also provided improved phages for the treatment of bacterial infections in honey bees.

Evaluating Atlantic Salmon (Salmo salar) as a Natural or Alternative Host for Piscine Myocarditis Virus (PMCV) Infection.

Cardiomyopathy syndrome (CMS) caused by piscine myocarditis virus (PMCV) has emerged with the rise of the aquaculture of Atlantic salmon (Salmo salar). The lack of cell culture cultivation has hampered the study of this infection. In this study, samples from naturally PMCV-infected Atlantic salmon from different commercial farms were collected and used. In situ hybridization (ISH) revealed intense staining of PMCV RNA in myocardial cells in the spongiform layer of the heart ventricle but almost no staining in the compact layer. In the kidneys, only sporadic staining was seen. Viral RNA was present in all organs, with the highest loads in the heart, kidney, and spleen. The high viral PMCV RNA loads in the heart were due to extensive viral mRNA transcription. The high ratio of viral mRNA to viral genomic dsRNA indicated active transcription but limited production of new viral particles. This suggests that the histopathological changes in the heart are caused by viral mRNA and corresponding viral proteins and not by virus particle formation. The production of full-length transcripts is regulated, with a reduction in the relative number of ORF3-containing transcripts at high transcription rates. Efforts to identify alternative hosts, such as fungi, were inconclusive, as fungal sequences were found inconsistently in the salmon tissue samples. The results of this study reinforce the need for further research to fully understand PMCV's life cycle and potential alternative hosts and its whereabouts when it is not infecting the hearts of the Atlantic salmon.

Improving Room Temperature Performance of All-Solid-State Polymer Batteries through Cell Activation

Solid polymer electrolytes (SPE) are gaining increasing attention for use in all-solid-state lithium batteries (ASSLB) due to their enhanced safety and simplified processing.[1] However, their conventional operation requires elevated temperatures.[2, 3] Here, we propose a straightforward hot-press activation method to facilitate cell operation at room temperature (r.t., 30 °C) for SPE-based ASSLB. This activation method induces grain amorphization, leading to a substantial reduction in grain boundary resistance within the SPE and achieving a fourfold increase in r.t. ionic conductivity. Furthermore, by decoupling Li-ion transport processes, the activation significantly diminishes the electrode-electrolyte interfacial resistances for both the cathode and anode, thereby enhancing kinetics and overall cell performance at r.t.. Through the application of an optimized activation procedure, all-solid-state LiFeO4 (LFP)|SPE|Li cells exhibit noteworthy performance enhancements, demonstrating both high specific capacity and stable cycling at r.t.References Mauger, A., et al., Building Better Batteries in the Solid State: A Review. Materials, 2019. 12(23).Chen, R.J., et al., The pursuit of solid-state electrolytes for lithium batteries: from comprehensive insight to emerging horizons. Materials Horizons, 2016. 3(6): p. 487-516.Mindemark, J., et al., Beyond PEO—Alternative host materials for Li + -conducting solid polymer electrolytes. Progress in Polymer Science, 2018. 81: p. 114-143.

Enforced specificity of an animal symbiosis.

Insect diversification has been catalyzed by widespread specialization on novel hosts - a process underlying exceptional radiations of phytophagous beetles, lepidopterans, parasitoid wasps, and inordinate lineages of symbionts, predators and other trophic specialists. The strict fidelity of many such interspecies associations is posited to hinge on sensory tuning to host-derived cues, a model supported by studies of neural function in host-specific model species. Here, we investigated the sensory basis of symbiotic interactions between a myrmecophile rove beetle and its single, natural host ant species. We show that host cues trigger analogous behaviors in both ant and symbiont. Cuticular hydrocarbons - the ant's nestmate recognition pheromones - elicit partner recognition by the beetle and execution of ant grooming behavior, integrating the beetle into the colony via chemical mimicry. The beetle also follows host trail pheromones, permitting inter-colony dispersal. Remarkably, the rove beetle also performs its symbiotic behaviors with ant species separated by ~95 million years, and shows minimal preference for its natural host over non-host ants. Experimentally validated agent-based modeling supports a scenario in which specificity is enforced by physiological constraints on symbiont dispersal, and negative fitness interactions with alternative hosts, rather than via sensory tuning. Enforced specificity may be a pervasive mechanism of host range restriction of specialists embedded within host niches. Chance realization of latent compatibilities with alternative hosts may facilitate host switching, enabling deep-time persistence of obligately symbiotic lineages.

Host Preference and Developmental Dynamics of Fall Armyworm <i>Spodoptera frugiperda</i> (J E Smith)

The invasive fall army worm Spodoptera frugiperda (J E Smith) is a major global agricultural pest, originally from tropical and subtropical America, now affecting over 80 plant species across Africa, Asia, and beyond. This study examines its host preferences and developmental dynamics, focusing on four host plants: Zea mays L., Glycine max L., Carica papaya L., and Brassica oleraceae var. acephala L. Using a complete randomized design, mortality and developmental rates of larvae were evaluated. These results revealed that C. papaya and B. oleraceae leaves resulted in maximum larval mortality (80 and 65%, respectively). This can be attributed to the presence of secondary metabolites like tannins, terpenoids, flavonoids, and alkaloids, which exhibit toxic and antifeedant properties. This study highlights the armyworm's ability to adapt to alternative hosts like G. max and B. oleraceae, even surviving on C. papaya leaves, typically used as a botanical pesticide.

Evaluation of host plant species for a trap cropping strategy in integrated pest management of pineapple mealybug (Dysmicoccus brevipes)

Pineapple mealybugs are responsible for the emergence of pineapple wilt disease and the subsequent transmission of the pineapple disease virus. This study aimed to evaluate the alternate host plants as potential trap crops for pineapple mealybug. A total of nine host plant species, banana, pumpkin, roselle, hibiscus, ground fig, okra, java grass, goose grass and rhodes grass were selected for the study. Thirty adult females of pineapple mealybug were reared on a pumpkin for two months. Three replicates of a plot (area covered with black netting measuring 3 m × 3 m) were set up. Nine host plant species, approximately 2–3 feet in a 16 inch × 16 inch polybag were arranged in a circle around the pumpkin. The effectiveness of the host plant species was determined by calculating the infestation of each plant species for six months (with two-week observations). Our findings revealed that the pineapple mealybug prefers banana with the greatest mean and SD value (621.7±172.7), followed by pumpkin (237.0±45.6) and the lowest one is rhodes grass (2.00±26.5). ANOVA results show that there is a significant difference between host plant species (F-value of 26.87 and a P-value < 0.00). The observations suggest that banana has the potential to be utilized as trap crops for pineapple mealybug, and can be considered in IPM strategy to control pineapple mealybug.

Genetic diversity analysis of Saccharosydne procerus in Hunan region, China.

Saccharosydne procerus serves as a significant alternative host for parasitoids of the important rice pest, rice planthoppers. Rearing S. procerus on the water bamboo plants near rice field can provide a parasitic site for parasitic wasps during the idle period of rice fields, thereby stabilizing the number of parasitoids and suppressing the number of rice planthoppers in the field. However, limited understanding of genetic diversity of S. procerus restricts its application. Therefore, this study aims to analyze the genetic diversity of S. procerus in Hunan region. In this study, 16 geographical populations of the S. procerus from the Hunan region were used. After screening, ISSR primers were employed for polymorphism detection. POPGENE32 software was used for genetic diversity analysis, and UPGMA clustering was applied for statistical analysis of different geographical populations to generate an evolutionary tree. Eleven ISSR primers were screened, resulting in the detection of 194 amplification locus, of which 126 were polymorphic. The average percentage of polymorphic locus was 64.95%. The mean Nei's gene diversity (H) was 0.2475, the mean Shannon's Information index (I) was 0.3708, and the Genetic diversity index among populations (Gst) was 0.3800. Cluster analysis identified three groups, with most populations concentrated in the second group, indicating no clear genetic structure. This suggests that the 16 populations of S. procerus exhibit high levels of genetic diversity.