Natural Parasite Research Articles

Hestia to Demeter: Reducing Agrochemical Pollution to Empower Women Farmers

The 2020 Farm to Fork strategy by the European Commission aimed to reduce agrochemical pollutants and protect biodiversity but stirred controversy due to conflicts between intensive agriculture demands and environmental priorities. Strict limits on agrochemical residues required farmers to produce less. The de-intensification and agroecology prone policy impacted livelihoods, sparking political upheaval. Due to lack of pesticide alternatives and extension services, Lebanese exports have faced challenges complying with residue restrictions. Agricultural laborers and consumers are exposed to high levels of pesticide residue. Undocumented refugee women form a significant part of the agricultural workforce, and women led agricultural cooperatives have minimal access to funding, exacerbating gender inequity. The American University of Beirut (AUB) has played a pivotal role in agroecology research, rural development, and gender equity. Knowledge transfer promotes civic awareness and private sector partnerships. Local Natural enemies and parasites emerged as a residue-free alternative to agrochemicals. Biocontrol-based integrated pest management holds great potential for mitigating pesticides hazards to human and environmental health. Launching the “natural predators” initiative from women-run farms holds a great promise in dually resolving the problems of agrochemical pollution and gender equity in the agricultural sector. Empowering women in agriculture aims to transform their role from care work to farm management. This paper focuses on the technical aspects of developing “natural enemies” as pesticides alternative for Lebanese agriculture, aiming to overcome export challenges and revitalize the economy. "Farm to Fork meets Hestia to Demeter" underscores AUB's commitment to sustainability aligns climate action with gender equity. By supporting women entrepreneurs and addressing climate change's impact on public health, the initiative contributes to AUB's broader mission of advancing Lebanon and the region through Education for Sustainable Development.

Parasite diversity among domestic goats of tropical monsoon climatic zone in India.

Among different climatic zones in India, the tropical monsoon region comprises a diverse ecosystem characterized by the endemic nature of several parasites including certain emerging and re-emerging vector-borne pathogens of humans, whereas a systematic investigation of the occurrence of different parasites among domestic goats in this area is not yet explored. The goal of the present study is to explore the parasite diversity focusing on molecular identification of vector-borne hemoparasites and its health impacts on domestic goats reared in the tropical monsoon climate zone of Kerala, India. Among 227 goats presented to the Teaching Veterinary Clinical Complex (TVCC) in the monsoon months of 2023, thirty animals were recruited for the study. The animals were screened for the presence of different hemoparasites (Anaplasma spp., Theileria spp., and Babesia spp.), ectoparasites (ticks, lice, and fleas), and gastrointestinal (GI) parasites (hookworms, threadworms, tapeworms, whipworms, and coccidia). The isolated hemoparasites were further characterized by sequencing and phylogenetic analysis. The correlation studies to elucidate the association between the occurrence of different parasites and clinical manifestations (hyperthermia, pallor of mucous membrane, circulatory failure, respiratory signs, neurological instability, and GI signs), blood picture (anemia, leukopenia, thrombocytopenia), demographics (sex and age), and treatment history (hemoparasitic therapy, ectoparasiticidal application, and prophylactic deworming) were conducted. The co-infection status of these parasites was also evaluated. A substantial portion of the goats in the study group was found to be affected by vector-borne hemoparasitic diseases and their arthropod vectors or GI parasites or both. This can be attributed to the constantly warm and humid climate of the region, which is favorable for the survival and growth of different life cycle stages of these parasites and vectors. A strategic parasitic disease surveillance-cum-control program is the need of the hour for ensuring climate resilience and profitable goat farming in the region.

Enhancing sandalwood growth: Host plant selection and salinity stress tolerance

Being a semi-root parasitic nature, sandalwood steals water and nutrients from host species. Therefore, it is crucial to research the influence of salinity stress on host-parasite relationships both theoretically and practically, for the successful establishment of sandalwood plantations. To find out the best suited host species for sandalwood, a RBD experiment was conducted to identify the effect of salt stress on sandalwood planted with two selected host species (Alternanthera sp. and Azadirachata indica) and without host species. After 300 days of establishment, morphological traits were recorded and noted that plant height, collar diameter and root length was higher in Azadirachta indica as compared to other host species. Significant reduction in morphological traits was recorded under salt stress condition. Similarly, higher root biomass was noted in Azadirachta indica under control as well as in saline conditions. On the other side, shoot biomass was higher in sandalwood grown with Alternanthera sp. Sandalwood grown in the absence of host plant showed no survival under salinity stress. Plant water traits were higher when sandalwood cultivated with A. indica while lowest in sandalwood grown in the absence of host species. Na+/K+ ratio and other nutrients (viz., Nitrogen, Phosphorus and Potassium) was higher sandalwood planted with A. indica while poorer in Sandalwood planted without host species. The results revealed that A. indica could be best host for sandalwood under stress as well as control conditions which enhances the growth and physiology of sandalwood.

Landscape and insecticide use affecting the Leucoptera coffeella infestation and the natural parasitism spatiotemporal distribution in brazilian coffee agroecosystems

Monitoring the coffee leaf miner and natural parasitism is an important part of integrated pest management, and knowing the spatial distribution patterns of this pest can help improve sampling plans. This study aimed to determine spatial and temporal distributions of the coffee leaf miner infestation and natural parasitism in coffee plantations of different insecticide use and landscape configurations in the Planalto region, Bahia, Brazil. We monitored five coffee farms with different insecticide management practices in insecticide use and landscape features during two seasons, from December 2020 to November 2021. In each coffee farm, four regular grid plots of 30 points were established, for a total of 120 sample points per farm, that were georeferenced. Each point was a group of five coffee plants within 5 m of each other, 30 m in distance. Monthly collections of mined leaves were carried out at each sampling point to determine the L. coffeella infestation and natural parasitism rates. Geostatistical analysis was used to determine the spatial distribution of infestations and natural parasitism using semivariograms. Landscape metrics of each coffee plantation were surveyed in buffers ranging from 500 to 3000 m to assess their effects on population aggregation. Infestations of L. coffeella and natural parasitism of the pest occurred throughout the year and at varying intensities among farms. Leucoptera coffeella infestation and natural parasitism exhibited moderate aggregation patterns in most sampling months. The aggregation of L. coffeella infestations and natural parasitism were influenced by landscape and insecticide use. Forest cover, land cover use diversity, and insecticide use increased aggregation of L. coffeella infestations and natural parasitism, whereas edge density decreased aggregation of both. The study suggests that it may be beneficial to review the current sampling plans for the coffee leaf miner and the natural parasitism in coffee farms. This information can improve the integrated management of the pest in coffee farms and assist in decision-making regarding L. coffeella control strategies.

Resources modulate developmental shifts but not infection tolerance upon coinfection in an insect system.

Energetic resources fuel immune responses and parasite growth within organisms, but it is unclear whether energy allocation is sufficient to explain changes in infection outcomes under the threat of multiple parasites. We manipulated diet in flour beetles ( Tribolium confusum ) infected with two natural parasites to investigate the role of resources in shifting metabolic and immune responses after single and co-infection. Our results suggest that gregarine parasites alter the within-host energetic environment, and by extension juvenile development time, in a diet- dependent manner. Gregarines do not affect host resistance to acute bacterial infection but do stimulate the expression of an alternative set of immune genes and promote damage to the gut, ultimately contributing to reduced survival regardless of diet. Thus, energy allocation is not sufficient to explain the immunological contribution to coinfection outcomes, emphasizing the importance of mechanistic insight for predicting the impact of coinfection across levels of biological organization.

Complex Genomes of Early Nucleocytoviruses Revealed by Ancient Origins of Viral Aminoacyl-tRNA Synthetases.

Aminoacyl-tRNA synthetases (aaRSs), also known as tRNA ligases, are essential enzymes in translation. Owing to their functional essentiality, these enzymes are conserved in all domains of life and used as informative markers to trace the evolutionary history of cellular organisms. Unlike cellular organisms, viruses generally lack aaRSs because of their obligate parasitic nature, but several large and giant DNA viruses in the phylum Nucleocytoviricota encode aaRSs in their genomes. The discovery of viral aaRSs led to the idea that the phylogenetic analysis of aaRSs can shed light on ancient viral evolution. However, conflicting results have been reported from previous phylogenetic studies: one posited that nucleocytoviruses recently acquired their aaRSs from their host eukaryotes, while another hypothesized that the viral aaRSs have ancient origins. Here, we investigated 4,168 nucleocytovirus genomes, including metagenome-assembled genomes (MAGs) derived from large-scale metagenomic studies. In total, we identified 780 viral aaRS sequences in 273 viral genomes. We generated and examined phylogenetic trees of these aaRSs with a large set of cellular sequences to trace evolutionary relationships between viral and cellular aaRSs. The analyses suggest that the origins of some viral aaRSs predate the last common eukaryotic ancestor. Inside viral aaRS clades, we identify intricate evolutionary trajectories of viral aaRSs with horizontal transfers, losses, and displacements. Overall, these results suggest that ancestral nucleocytoviruses already developed complex genomes with an expanded set of aaRSs in the proto-eukaryotic era.

Diversity and selection analyses identify transmission-blocking antigens as the optimal vaccine candidates in Plasmodium falciparum

A highly effective vaccine for malaria remains an elusive target, at least in part due to the under-appreciated natural parasite variation. This study aimed to investigate genetic and structural variation, and immune selection of leading malaria vaccine candidates across the Plasmodium falciparum's life cycle. We analysed 325P.falciparum whole genome sequences from Zambia, in addition to 791 genomes from five other African countries available in the MalariaGEN Pf3k Database. Ten vaccine antigens spanning three life-history stages were examined for genetic and structural variations, using population genetics measures, haplotype network analysis, and 3D structure selection analysis. Among the ten antigens analysed, only three in the transmission-blocking vaccine category display P. falciparum 3D7 as the dominant haplotype. The antigens AMA1, CSP, MSP119 and CelTOS, are much more diverse than the other antigens, and their epitope regions are under moderate to strong balancing selection. In contrast, Rh5, a blood stage antigen, displays low diversity yet slightly stronger immune selection in the merozoite-blocking epitope region. Except for CelTOS, the transmission-blocking antigens Pfs25, Pfs48/45, Pfs230, Pfs47, and Pfs28 exhibit minimal diversity and no immune selection in epitopes that induce strain-transcending antibodies, suggesting potential effectiveness of 3D7-based vaccines in blocking transmission. These findings offer valuable insights into the selection of optimal vaccine candidates against P.falciparum. Based on our results, we recommend prioritising conserved merozoite antigens and transmission-blocking antigens. Combining these antigens in multi-stage approaches may be particularly promising for malaria vaccine development initiatives. Purdue Department of Biological Sciences; Puskas Memorial Fellowship; National Institute of Allergy and Infectious Diseases (U19AI089680).

Are Rattus rattus fleas invasive? Evaluation of flea communities in invasive and native rodents in Chile.

Co-invasion, characterized by the simultaneous introduction of hosts and parasites with the latter establishing themselves in native hosts, is a phenomenon of ecological concern. Rattus rattus, a notorious invasive species, has driven the extinction and displacement of numerous avian and mammalian species and serves as a key vector for diseases affecting both humans and wildlife. Among the parasites hosted by R. rattus are fleas, which exhibit obligate parasitic behaviour, a generalist nature and high prevalence, increasing the likelihood of flea invasion. Simultaneously, invasive species can serve as hosts for native parasites, leading to potential amplification or dilution of parasite populations in the environment. In Chile, R. rattus has been present since the 17th century because of the arrival of the Spanish colonizers through the ports and has spread throughout urban, rural and wild Chilean territories. This study aims to evaluate whether co-invasion of native fleas of invasive rats occurs on native rodents in Chile and to determine whether black rats have acquired flea native to Chile during their invasion. For this, we captured 1132 rodents from 26 localities (20° S-53° S). Rattus rattus was found coexisting with 11 native rodent species and two species of introduced rodents. Among the native rodents, Abrothrix olivacea and Oligoryzomys longicaudatus exhibited more extensive sympatry with R. rattus. We identified 14 flea species associated with R. rattus, of which only three were native to rats: Xenopsylla cheopis, Leptopsylla segnis and Nosopsyllus fasciatus. These three species presented a higher parasite load in black rats compared to native fleas. Leptopsylla segnis and N. fasciatus were also found associated with native rodent species that cohabit with R. rattus. The remaining species associated with R. rattus were fleas of native rodents, although they were less abundant compared to those associated with native rodents, except for Neotyphloceras pardinasi and Sphinctopsylla ares. Although there has been evidence of flea transmission from rats to native species, the prevalence and abundance were relatively low. Therefore, it cannot be definitively concluded that these fleas have established themselves in native rodent populations, and hence, they cannot be classified as invasive fleas. This study underscores R. rattus' adaptability to diverse environmental and geographical conditions in Chile, including its capacity to acquire fleas from native rodents. This aspect has critical implications for public health, potentially facilitating the spread of pathogens across various habitats where these rats are found.

Postnatal zinc deficiency due to giardiasis disrupts hippocampal and cerebellar development.

Giardiasis and zinc deficiency have been identified as serious health problems worldwide. Although Zn depletion is known to occur in giardiasis, no work has investigated whether changes occur in brain structures. Three groups of gerbils were used: control (1), orogastrically inoculated on day 3 after birth with trophozoites of two isolates of Giardia intestinalis (HGINV/WB) group (2 and 3). Estimates were made at five ages covering: establishment of infection, Giardia population growth, natural parasite clearance and a post-infection age. QuantiChrome zinc assay kit, cresyl violet staining and TUNEL technique were used. A significant decrease (p<0.01) in tissue zinc was observed and persisted after infection. Cytoarchitectural changes were observed in 75% of gerbils in the HGINV or WB groups. Ectopic pyramidal neurons were found in the cornus ammonis (CA1-CA3). At 60 and 90 days of age loss of lamination was clearly visible in CA1. In the dentate gyrus (DG), thinning of the dorsal lamina and abnormal thickening of the ventral lamina were observed from 30 days of age. In the cerebellum, we found an increase (p<0.01) in the thickness of the external granular layer (EGL) at 14 days of age that persisted until day 21 (C 3 ± 0.3 μm; HGINV 37 ± 5 μm; WB 28 ± 3 μm); Purkinje cell population estimation showed a significant decrease; a large number of apoptotic somas were observed scattered in the molecular layer; in 60 and 90 days old gerbils we found granular cell heterotopia and Purkinje cell ectopia. The pattern of apoptosis was different in the cerebellum and hippocampus of parasitized gerbils. The morphological changes found suggest that neuronal migration is affected by zinc depletion caused by giardiasis in early postnatal life; for the first time, the link between giardiasis-zinc depletion and damaged brain structures is shown. This damage may explain the psychomotor/cognitive delay associated with giardiasis. These findings are alarming. Alterations in zinc metabolism and signalling are known to be involved in many brain disorders, including autism.

Damage and Entomophagy in Natural Infestations of Spodoptera frugiperda (Lepidoptera: Noctuidae) in Maize Landraces in Oaxaca, Mexico1

Abstract The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), seriously damages maize (Zea mays L.) crops in tropical, subtropical, and temperate zones of Mexico and around the world. This study was conducted to evaluate the damage caused by S. frugiperda to six native maize populations and the natural parasites of S. frugiperda in three localities from Oaxaca, Mexico. Two native maize populations each of the Zapalote Chico, Bolita, and Conico-Chalqueño races were used. Plantings were done at Coatecas Altas, Santa Lucia Miahuatlan, and Villa de Zaachila under a randomized complete block design with four replications. The agroecological conditions of cultivation influenced the damage caused by S. frugiperda and influenced its natural parasitism. The ordered weighted mean damage in the localities was Villa de Zaachila (1.40–4.92) &amp;gt; Coatecas Altas (1.33–4.06) &amp;gt; Santa Lucia Miahuatlan (0.53–1.00). The order of parasitism rates in the localities was Villa de Zaachila (56.16%) ≈ Santa Lucia Miahuatlan (37.59%) &amp;gt; Coatecas Altas (14.27%). Zapalote Chico populations were less damaged by S. frugiperda larvae and flowered earlier than did the Conico-Chalqueño and Bolita populations. Thirteen parasitoid species and nematodes were recorded attacking S. frugiperda. Chelonus insularis Cresson was the most abundant parasitoid species across the locations. Members of 17 families of predators and 12 families of parasitoids also were identified as potential natural enemies of S. frugiperda. The population dynamics of this armyworm were determined by the environmental conditions of the location, maize population, transition from the vegetative to the reproductive stage, and presence of natural enemies, whereas natural parasitism was influenced only by location.

Distribution and host range of a highly invasive parasitic copepod

AbstractThe parasitic copepod Neoergasilus japonicus (Ergasilidae), native to East Asia, has spread rapidly around the world over the past half-century and now represents a clear example of successful parasitic invader. The species is now found in western Asia, Europe, America and Africa, with aquaculture and fish introductions identified as the primary vectors of dispersal. Regional field investigations have revealed surprisingly high number of affected localities, indicating potentially wider distribution than currently recognised. Neoergasilus japonicus exhibits low host specificity, parasitising a diverse range of freshwater fishes. This study updates the global fish host species list to 132, spanning 27 families across 15 orders, with Cypriniformes identified as the most susceptible host species. Under experimental conditions in this study, however, N. japonicus avoided its natural host, topmouth gudgeon Pseudorasbora parva, suggesting a level of resistance to its native parasite. Piscivorous and demersal fish were less infected by copepods than planktivorous, benthivorous, pelagic and benthopelagic species, reflecting the ecology of both the parasite and its hosts. An ability to re-attach to another host, though limited, was confirmed under experimental conditions. Recognising the ecological impacts and potential consequences associated with the introduction of non-native parasites emphasises the need for continuous monitoring and research globally.

Weather Parameter’s Impact on Natural Parasitization by Campoletis chlorideae Uchida in Chickpea Ecosystem - New Alluvial Zone of West Bengal

Background: A major biotic constraint in chickpea (Cicer arietinum L.) production is gram pod borer, Helicoverpa armigera (Hübner). However, the population of this pest is reduced to some extent by a solitary endo-larval parasitoid, Campoletis chlorideae Uchida under field conditions. Climate change has a greater impact on natural enemies’ effectiveness used in field-level pest management. Therefore, the present study was conducted to understand the impact of weather factors on C. chlorideae parasitization rate of H. armigera in chickpea grown in the new alluvial agro-climatic zone of West Bengal. Methods: Chickpea was grown in a randomized complete block design (RCBD) with three replications during Rabi 2017-18, 2018-19 and 2019-2020, at Mondouri farm, Bidhan Chandra Krishi Visawavidayala, Mohanpur, West Bengal. To know the most significant weather parameter which influences C. chlorideae parasitization or parasitoid incidence, H. armigera larvae (2nd instar) collected from the field experiment were reared until cocoon formation and parasitization % was correlated with weather parameters and subsequently subjected to stepwise regression analysis. Result: The larval endo-parasitoid, C. chlorideae marked its first appearance from 3rd SMW after the appearance of H. armigera and its activity was high (68% to 72% parasitization) during the flowering to pod initiation stage and thereafter declined gradually. Among the weather variables, only temperature (maximum and minimum) had a consistent and significant negative correlation with C. chlorideae incidence and was responsible for nearly 50% C. chlorideae incidence. An increase in 1°C temperature results in a decrease of 4% parasitoid incidence. Thus, climate change in the near future will have a considerable influence on the overall survival, development and rate of parasitization of parasitoids.

Incidence of Rice Stem Borers in Coastal Andhra Pradesh with Emphasis on &lt;i&gt;Sesamia inferens&lt;/i&gt; (Walker)

A roving survey was conducted in the rice crop grown in coastal districts of Andhra Pradesh during rabi, 2021-22 and 2022-23. Overall mean stem borer incidence varied from 13.59% - 14.83% in both the seasons. Larvae of Scirpophaga incertulas (Walker), Sesamia inferens (Walker), Chilo polychrysus (Meyers) and Chilo auricilius (Dudgeon), were recorded from four districts during the survey. Among the stem borers, S. incertulas was the most predominant species (53.37%) followed by S. inferens (44.7%). Natural larval parasitization (21%) of S. inferens by Cotesia flavipes Cameron was observed in West Godavari district. The biology of S. inferens was studied on rice cv. MTU 1121. The average larval period recorded was 32.40± 0.35 days. Total life cycle of S. inferens ranged between 41-65 and 46-73 days for male and female moths, respectively. Current study suggests that S. inferens could be a potential threat to rice cultivation in coastal Andhra Pradesh.

First report of Telenomus remus Nixon (Hymenoptera: Scelionidae) on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Egypt

BackgroundThe polyphagous alien invasive pest, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), invaded Africa and has so far spread across the continent, causing devastating impacts on maize production. In Egypt, the management of the pest by maize growers has been characterized by the application of broad-spectrum synthetic chemical insecticides, a strategy which is associated with various detrimental effects on the environment and human health. To mitigate the overreliance and excessive use of those synthetic chemicals, biological control using egg parasitoids species provides an ecologically friendly and sustainable management strategy. In that regard, this study had the objective of identifying the natural existing egg parasitoids, which could be effectively used in augmentative biocontrol of the pest in Egypt.ResultsFor the first time in Egypt, natural occurrence and parasitism of Telenomus remus Nixon, 1937 (Hymenoptera: Scelionidae) on S. frugiperda egg masses was recorded. Infested maize farms in Qena Governorate, Egypt, were surveyed, and S. frugiperda egg masses were collected and incubated in the laboratory. Emerging parasitoids’ wasps were grouped based on their morphological similarities. Natural parasitism of the egg parasitoids (Telenomus sp.) was computed from the parasitized field collected egg masses. In addition, to confirm the laboratory parasitism and suitability of the parasitoid, Telenomus sp. to develop on S. frugiperda, the parasitoid was reared on S. frugiperda egg masses for three generations under laboratory conditions. Moreover, both morphological and molecular identifications were conducted. The recovered parasitoid samples from the field S. frugiperda egg masses were Telenomus remus (Nixon) (Hymenoptera: Scelionidae). Moreover, the average field parasitism level by T. remus on S. frugiperda was 15.9%, while under laboratory conditions, the parasitism was 63.5%.ConclusionsThe natural occurrence of T. remus in Egypt and its association with S. frugiperda is an important finding upon which augmentative biocontrol strategy can be leveraged on to sustainably manage the pest populations.

Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity

BackgroundIn 2021 and 2023, the World Health Organization approved RTS,S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (PfCSP), but polymorphisms in the gene raise concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission intensities in Mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country.MethodsThe analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of Mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright’s inbreeding coefficient (Fws), Wright’s fixation index (FST), principal component analysis, nucleotide diversity, and Tajima’s D were used to assess within-host parasite diversity, population structure and natural selection.ResultsBased on Fws (< 0.95), there was high polyclonality (ranging from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST = 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima’s D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences revealed 50 different haplotypes (H_1 to H_50), with only 2% of sequences matching the 3D7 strain haplotype (H_50). Conversely, with the NF54 strain, the Pfcsp C-terminal sequences revealed 49 different haplotypes (H_1 to H_49), with only 0.4% of the sequences matching the NF54 strain (Hap_49).ConclusionsThe findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima’s D values, consistent with balancing selection for variants within Th2R and Th3R regions. The study observed differences between the intended haplotypes incorporated into the design of RTS,S and R21 vaccines and those present in natural parasite populations. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines.

Phylogeny, morphology, virulence, ecology, and host range of Ordospora pajunii (Ordosporidae), a microsporidian symbiont of Daphnia spp.

The net outcome of symbiosis depends on the costs and benefits to each partner. Those can be context dependent, driving the potential for an interaction to change between parasitism and mutualism. Understanding the baseline fitness impact in an interaction can help us understand those shifts; for an organism that is generally parasitic, it should be easier for it to become a mutualist if its baseline virulence is relatively low. Recently, a microsporidian was found to become beneficial to its Daphnia hosts in certain ecological contexts, but little was known about the symbiont (including its species identity). Here, we identify it as the microsporidium Ordospora pajunii. Despite the parasitic nature of microsporidia, we found O. pajunii to be, at most, mildly virulent; this helps explain why it can shift toward mutualism in certain ecological contexts and helps establish O. pajunii is a valuable model for investigating shifts along the mutualism-parasitism continuum.

Aspectos bioecológicos de Cynea (Cynea) diluta (Herrich-Schäffer, 1869) (Lepidoptera: Hesperiidae: Hesperiinae)

In Hesperiidae (Lepidoptera), many species build shelters during their ontogeny which may be serve as a scape strategy to reduce attacks from natural enemies and dislodgment from the host plant. This paper provides bioecological information regarding host plant, natural parasitism, and distribution of Cynea (Cynea) diluta (Herrich-Schäffer) (Hesperiidae: Hesperiinae) collected near remnants of the Atlantic Forest “Centro de Endemismo Pernambuco” (CEPE), Northeast Region of Brazil. Larvae and pupae, the later showing signs of parasitism, were collected from a garden at the Universidade Federal de Alagoas, Maceió, State of Alagoas, Brazil. They were brought to the laboratory to record emergences and possible parasitoids. Data from distribution were obtained from labels of hesperiid deposited from the Coleção Entomológica Padre Jesus Santiago Moure,Curitiba, State of Paraná. The host plant was identified as Alpinia purpurata (Vieill.) K. Schum. (Zingiberaceae). From the 13 larvae and two pupae collected in the environment, 20 specimens of Brachymeria sp. (Hymenoptera: Chalcididae) emerged from the pupae. This is the first report of parasitism on pupae of Cynea (C.) diluta.

The link between functional response and longevity of Trichogramma evanescens strains indigenous to Türkiye: A comparative assessment of parameters

AbstractA previous comprehensive survey in the Mediterranean and Southeastern regions of Türkiye investigating the natural egg parasitism of lepidopteran maize pests, Sesamia spp, (Lepidoptera: Noctuidae) Ostrinia nubilalis Hbn. and Chilo partellus (Swinhoe; Lepidoptera: Crambidae) by Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) yielded successful establishment of laboratory cultures of six strains molecularly clustering into two main groups. In this study, the functional response and adult longevity of the strains reared and tested on a factitious host, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were investigated to provide insights into their potential as candidate biocontrol agents under constant laboratory conditions. The functional response modelling process consisted of two main sequential steps: model selection using polynomial logistic regression and parameter estimation using an iterative maximum likelihood estimation method. The functional response of two strains showed negative linear parameters (type II): HAP068M and HAP268S. Although their attack rate did not differ, the handling time of HAP268S was longer than that of HAP068M. In contrast, four strains had positive linear and negative quadratic parameters (type III) in their functional response: HAP044S, HAP070S, HAP210S, and HAP258M. The strains exhibiting type III functional response did not differ in their handling time, while HAP044S had a higher attack coefficient than HAP070S, HAP210S, and HAP258M. The longevity of both female and male adults significantly differed between strains. More importantly, the females belonging to strains exhibiting type II functional response presented a shorter longevity, compared to those with type III functional response. Males also showed a similar trend in their longevity. This paper discusses the differences in functional response types and estimated parameters of the strains in relation to their relevance for biological control programs and reveals a link between their functional response and longevity as potential reciprocal predictors.

Promastigote EPS secretion and haptomonad biofilm formation as evolutionary adaptations of trypanosomatid parasites for colonizing honeybee hosts

Bees are major pollinators involved in the maintenance of all terrestrial ecosystems. Biotic and abiotic factors placing these insects at risk is a research priority for ecological and agricultural sustainability. Parasites are one of the key players of this global decline and the study of their mechanisms of action is essential to control honeybee colony losses. Trypanosomatid parasites and particularly the Lotmaria passim are widely spread in honeybees, however their lifestyle is poorly understood. In this work, we show how these parasites are able to differentiate into a new parasitic lifestyle: the trypanosomatid biofilms. Using different microscopic techniques, we demonstrated that the secretion of Extracellular Polymeric Substances by free-swimming unicellular promastigote forms is a prerequisite for the generation and adherence of multicellular biofilms to solid surfaces in vitro and in vivo. Moreover, compared to human-infective trypanosomatid parasites our study shows how trypanosomatid parasites of honeybees increases their resistance and thus resilience to drastic changes in environmental conditions such as ultralow temperatures and hypoosmotic shock, which would explain their success thriving within or outside their hosts. These results set up the basis for the understanding of the success of this group of parasites in nature and to unveil the impact of such pathogens in honeybees, a keystones species in most terrestrial ecosystems.

Phylogenetic position of Pratylenchus sp. (Nematoda: Pratylenchidae) associated with grasslands using 28S rDNA from South Africa

Plant-parasitic nematodes are the main nematodes that live in the soil, causing yield loss in various crops. As endoparasites, Pratylenchus species can reduce the yield of grass and other plants by feeding on their roots. Because of its parasitic nature on plants, this species requires careful identification; in South Africa's Limpopo Province, grasslands are among the most vital agricultural resources. Therefore, this molecular study was conducted in 2023 at Limpopo University to identify the nematode from South Africa's soils using 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. The nematode was identified as Pratylenchus. Afterward, 28S rDNA was amplified using specific primers to identify the nematode at the molecular level. The Nblast analysis based on the large subunit ribosomal DNA showed South African Pratylenchus had 99% similarity (OQ343703) with the South African population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as Pratylenchus in the same clade with highly supported (100) bootstrap values. In conclusion, this species was identified using 28S rDNA; however, other rDNA markers, such as ITS rDNA and mtDNA is recommended for a better understanding of Pratylenchus phylogeny.