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BACKGROUND: The chicken body louse is an obligate ectoparasite of domestic chickens. Chicken body lice feed on feathers, and infestation with this louse is linked to decreases in egg production, hen weight, and feed conversion efficiency. However, it is unknown how chicken body lice impact egg-laying chickens in cage-free environments. Welfare and behavior metrics were collected from flocks of egg-laying chickens either infested with chicken body lice or left uninfested. METHODS: In two trials, two flocks of cage-free commercial egg-laying chickens were infested with chicken body lice or maintained as uninfested controls. At three timepoints, behavior and welfare of all chickens was measured. On-animal sensors were used to quantify pecking, preening, and dustbathing behavior. Other animal-based welfare metrics included recording comb wounds and skin lesions. RESULTS: Birds infested with chicken body lice exhibited significantly more preening behaviors than uninfested birds, even at low louse levels. Moderate or severe skin lesions were detected on birds that were moderately infested with chicken body lice while skin lesions were never detected on uninfested birds. CONCLUSIONS: The welfare of chickens was impacted by the chicken body louse, a chewing louse that primarily feather feeds. Evidence of skin lesions on infested birds suggests that lice may cause more damage to birds than previously thought, and further evaluation of louse economic damage is necessary.

Identifying the factors that affect host–parasite interactions is essential for understanding the ecology and dynamics of vector‐borne diseases and may be an important component of predicting human disease risk. Characteristics of hosts themselves (e.g., body condition, host behavior, immune defenses) may affect the likelihood of parasitism. However, despite highly variable rates of parasitism and infection in wild populations, identifying widespread links between individual characteristics and heterogeneity in parasite acquisition has proven challenging because many zoonoses exist over wide geographic extents and exhibit both spatial and temporal heterogeneity in prevalence and individual and population‐level effects. Using seven years of data collected by the National Ecological Observatory Network (NEON), we examined relationships among individual host condition, behavior, and parasitism by Ixodid ticks in a keystone host species, the white‐footed mouse, Peromyscus leucopus. We found that individual condition, specifically sex, body mass, and reproductive condition, had both direct and indirect effects on parasitism by ticks, but the nature of these effects differed for parasitism by larval versus nymphal ticks. We also found that condition differences influenced rodent behavior, and behavior directly affected the rates of parasitism, with individual mice that moved farther being more likely to carry ticks. This study illustrates how individual‐level data can be examined using large‐scale datasets to draw inference and uncover broad patterns in host–parasite encounters at unprecedented spatial scales. Our results suggest that intraspecific variation in the movement ecology of hosts may affect host–parasite encounter rates and, ultimately, alter zoonotic disease risk through anthropogenic modifications and natural environmental conditions that alter host space use. [ABSTRACT FROM AUTHOR]

Bonelli's Eagle is an endangered species with little information on its ectoparasites. We studied their chewing lice (Phthiraptera: Amblycera, Ischnocera) infestations by visually searching the plumage of 64 wild and captive specimens. Three different species were identified: Degeeriella sp., Colpocephalum impressum and Laemobothrion maximum. This is the first case of Laemobothrion maximum on Bonelli's Eagle described. We also observe its haematophagous behavior. Due to the low prevalence of infestations, no alterations in the host health are described. [ABSTRACT FROM AUTHOR]

The Colombian weasel, Neogale felipei, is a rare carnivoran known only from nine localities, eight in Colombia and one in Ecuador. Recent records have expanded our understanding of the distribution and threats that this mammal faces, but the species is still among the rarest Neotropical carnivores. Here, we present an update to the distribution of N. felipei based on a recent record obtained in the Cordillera Occidental (Western Cordillera) of Colombia, and information on internal and external morphology using noninvasive technique such as X-rays of museum preserved specimens. We also documented the presence of lice, Neotrichodectes minutus, which is the first documented ectoparasite of the species. With the new records, the species is currently known from 12 localities (11 in Colombia and one in Ecuador). We also present the first radiographic analyses for N. felipei and the obtained vertebral formula (49 total vertebrae) fits into the range reported for the species and other mustelids. Considering that the Colombian weasel is one of the rarest carnivores of the Neotropics, our work represents a noteworthy contribution to several aspects of the anatomy, distribution, and natural history of this rare carnivoran. [ABSTRACT FROM AUTHOR]

Bat-associated hematophagous ectoparasites have been found harboring zoonotic and potentially zoonotic pathogens. Some species, such as bat ticks, occasionally feed on humans and other non-chiropteran hosts. A structured research strategy combined with risk assessment could enhance our understanding of which bat-associated parasites may act as vectors of zoonotic pathogens. Future research needs improved guidelines, focusing on a One Health strategy to predict and prevent potential pathogen spillovers. Bats are increasingly in the focus of disease surveillance studies as they harbor pathogens that can cause severe human disease. In other host groups, ectoparasitic arthropods play an important role in transmitting pathogens to humans. Nevertheless, we currently know little about the role of bat-associated ectoparasites in pathogen transmission, not only between bats but also to humans and other species, even though some of these parasites occasionally feed on humans and harbor potentially zoonotic organisms. In this work, we summarize current knowledge on the zoonotic risks linked to bat-associated ectoparasites and provide novel risk assessment guidelines to improve targeted surveillance efforts. Additionally, we suggest research directions to help adjust surveillance strategies and to better understand the eco-epidemiological role of these parasites. [ABSTRACT FROM AUTHOR]

A new species of pseudionine parasite is described from the deep-sea shrimp Notostomus gibbosus A. Milne-Edwards, 1881, collected in the Gulf of Mexico, the first record of a bopyrid parasitizing any member of the family Acanthephyridae Spence Bate, 1888. Morphological and molecular data are provided to support the inclusion of the new species and 12 other branchial ectoparasites of caridean shrimps in the genus Cryptione Hansen, 1897 that is resurrected herein. Cryptione is sister to the genus Pseudione sensu stricto, ectoparasites of axiid and callianassid shrimps as well as nephropid lobsters. The new species Cryptione grandis can be distinguished from its closest congeners including C. parviramus (Adkison, 1988) from the Gulf of Mexico by several female and male characters. The epicaridium larvae of C. grandis were examined with scanning electron microscopy (SEM), only the second description of this stage for any species in the genus. A table listing all species in Cryptione and taxonomic notes on some species are provided. [ABSTRACT FROM AUTHOR]

Fleas, along with one of their host species, Meriones unguiculatus, possess the capability to act as vectors in the transmission of plague. Parasitism by fleas may markedly influence the physiology and immune system of their hosts. Gut microbiota plays an important role in the growth and development of rodents. However, few studies have explored the impacts of ectoparasitic flea on the gut microbiome of rodents. This study investigated the immunological responses and changes in the gut microbial diversity and composition in both wild and laboratory rodents infested with fleas and laboratory rodents infested with Ctenocephalides felis. We measured immune reactions post-infestation by enzyme-linked immunosorbent assay (ELISA) and explored the effects of ectoparasitic infestation on the diversity and composition of the rodent gut microbiota in microbiome studies by 16S rRNA gene sequencing techniques. After flea infestation, results from 16S rRNA gene sequencing techniques indicated a significant increase in alpha diversity, affecting the composition of the gut microbiota. At the genus level, the abundance of the harmful bacterium Desulfovibrio increased. Beta diversity analyses showed significant differences between the gut microbiota of the experimental and control groups. ELISA results revealed significantly elevated levels of IgG in parasitized mice, while the differences in IgA levels were not significant. Flea infections affect the composition and diversity of the gut microbiota in the M. unguiculatu, and it has been found that the biomarker Desulfovibrio increases following flea infection in these rodents. Our results indicate that the gut microbiota can regulate the stability of the rodent-flea system. These findings may provide a foundation for exploring preventive measures against plague and aid in developing more effective treatments for the infection. [ABSTRACT FROM AUTHOR]

Simple Summary: Chiggers are common ectoparasites on rodents and other small mammals, and they transmit scrub typhus, a zoonotic disease. Dehong in Yunnan Province of southwest China is located on the China–Myanmar border, and it is a focus of scrub typhus. The present paper reports the infestation and distribution of chiggers on small mammals in Dehong for the first time. From 1760 rodents and other sympatric small mammals, a total of 9309 chiggers were identified, representing 117 species. Most chigger species had low host specificity. Leptotrombidium deliense, a major vector of scrub typhus in China, was the dominant chigger species in Dehong, and it was mainly distributed in flatland areas and indoors. The infestation and community indexes of chiggers in mountainous areas and outdoors were higher than those in flatland areas and indoors. The species abundance distribution of the chigger community conformed to log-normal distribution, and the total number of chigger species was roughly estimated to be 147. The species diversity of the chigger community is high in Dehong, with an obvious environmental heterogeneity. The low host specificity of chiggers and the occurrence of a large number of L. deliense in Dehong would increase the transmission risk of scrub typhus on the China–Myanmar border. Chiggers (chigger mites) are a group of tiny arthropods, and they are the exclusive vector of Orientia tsutsugamushi (Ot), the causative agent of scrub typhus (tsutsugamushi disease). Dehong Prefecture in Yunnan Province of southwest China is located on the China–Myanmar border and is an important focus of scrub typhus. Based on the field surveys in Dehong between 2008 and 2022, the present paper reports the infestation and ecological distribution of chiggers on the body surface of rodents and other sympatric small mammals (shrews, tree shrews, etc.) in the region for the first time. The constituent ratio (Cr), prevalence (PM), mean abundance (MA), and mean intensity (MI) were routinely calculated to reflect the infestation of small-mammal hosts with chiggers. Additionally, the species richness (S), Shannon–Wiener diversity index (H), Simpson dominance index (D), and Pielou's evenness index (E) were calculated to illustrate the chigger community structure. Preston's log-normal model was used to fit the theoretical curve of species abundance distribution, and the Chao 1 formula was used to roughly estimate the expected total species. The "corrplot" package in R software (Version 4.3.1) was used to analyze interspecific relationships, and the online drawing software was used to create a chord diagram to visualize the host–chigger associations. From 1760 small-mammal hosts, a total of 9309 chiggers were identified as belonging to 1 family, 16 genera, and 117 species, with high species diversity. The dominant chigger species were Leptotrombidium deliense, Walchia ewingi, and Gahrliepia longipedalis, with a total Cr = 47.65% (4436/9309), among which L. deliense is the most important vector of Ot in China. The overall infestation indexes (PM, MA, and MI) and community parameters (S, H, and E) of chiggers in the mountainous areas and outdoors were higher than those in the flatland areas and indoors, with an obvious environmental heterogeneity. Leptotrombidium deliense was the dominant species in the flatland and indoors, while G. longipedalis was the prevalent species in the mountainous and outdoor areas. The species abundance distribution of the chigger community conformed to log-normal distribution with the theoretical curve equation: S (R) ′ = 28 e − [ 0.23 (R − 0) ] 2 , indicating the existence of many rare species and only a few dominant species in the community. The expected total number of chigger species was roughly estimated to be 147 species, 30 more than the 117 species actually collected, suggesting that some uncommon species may have been missed in the sampling survey. The host–parasite association analysis revealed that one host species can harbor different chigger species, and one chigger species can parasitize different host species with low host specificity. A positive or negative correlation existed among different chigger species, indicating a cooperative or competitive interspecific relationship. The species diversity of chiggers is high in Dehong on the China–Myanmar border, and a large host sample is recommended to find more uncommon species. There is an obvious environmental heterogeneity of the chigger community, with different species diversity and dominant species in different environments. The low host specificity of chiggers and the occurrence of a large number of L. deliense in Dehong, especially in flatland areas and indoors, would increase the risk of persistent transmission of scrub typhus in the region. [ABSTRACT FROM AUTHOR]

The problem most often encountered in fish farming is disease which can cause a decrease in fish production levels. Parasites cause one of the infectious diseases found in fish farming. The presence of parasites can cause a decrease in the quality of the growth of fish production. The purpose of this study was to identify the prevalence of ectoparasites on Nile tilapia in Sidoarjo, Indonesia. Ninety-six samples from two ponds were examined under the microscope to find out the presence of ectoparasite that exists in the outside body part of the fish. Samples were collected from skin, fins, tail, and gills using native methods and observed under a microscope in the Division of Parasitology Laboratory, Faculty of Veterinary Medicine, Universitas Airlangga. The results of this study showed 86 samples positively infected by ectoparasite and 10 showed negative. The ectoparasites found in this study were Trichodina sp., Chilodonella sp., Ichthyophthirius multifillis, Gyrodactylus sp., and Dactylogyrus sp. The highest prevalence is Trichodina sp. and Dactylogyrus sp. The number of fish infested by ectoparasite is 89.56%, this is classified in the usual category. The highest prevalence occurs in infestations of Trichodina sp. i.e.72.91% which were contained in the 70 samples. While the lowest prevalence was in Gyrodactylus sp. by 8.32% in 8 fish samples. Double infections from two different ponds were 70% within 33 samples which were included in the usual category. [ABSTRACT FROM AUTHOR]

This article explores the impact of ectoparasitic mites on cage-free egg production in the United States and strategies for managing these mites. The transition to cage-free housing has resulted in an increase in mite infestations, which negatively affect the health, behavior, and productivity of hens. The article discusses the genetic variability for mite resistance and the potential use of genomic selection to improve mite resistance in poultry populations. It also provides information on the biology of the northern fowl mite and poultry red mite, as well as various management strategies, including the use of pesticides and biosecurity measures. The authors stress the importance of monitoring and managing mite infestations in egg production and call for further research to develop effective and sustainable strategies for improving hen welfare. They suggest that genomic selection could be a promising approach for breeding mite-resistant poultry strains. [Extracted from the article]

Background & Aims: Human lice infestation is considered primordial in origin, and its control dates back several centuries. However, its social stigma and ostracism remain major public health issues, particularly among school children. The main aim of this survey was to determine the relative frequency of head lice and its effective qualitative parameters among primary schoolgirls on Qeshm Island, south of Iran. Materials & Methods: This descriptive analytic study was performed on Qeshm Island. From 38 private and municipal primary schools, six schools, each including at least 60 female students, were randomly selected; a sample size of about 270 was computed. Data were analyzed using SPSS version 22. Results: In this survey, 283 female primary school students with an average age of 9 ± 2.16 years were investigated, of whom 119 (42%) were infested with head lice. Infestation among 6 to 9- year-old students was significantly lower than in the higher age group (p < 0.001). There was also a significant association between the students’ bathing frequency and lack of head lice infestation (p < 0.05). A significant relationship was evident between the mothers’ education level and head lice infestation in students (p < 0.001). Conclusion: Low maternal literacy, inadequate bathing frequency, and 11-year-old girls were at risk of head lice infestation. To reduce this problem, there is an essential need for the implementation of health measures such as employing school nurses, promoting public access to health services, educating tutors, students, and their parents, conducting clinical exams, and periodic screening.

The problem most often encountered in fish farming is disease which can cause a decrease in fish production levels. Parasites cause one of the infectious diseases found in fish farming. The presence of parasites can cause a decrease in the quality of the growth of fish production. The purpose of this study was to identify the prevalence of ectoparasites on Nile tilapia in Sidoarjo, Indonesia. Ninety-six samples from two ponds were examined under the microscope to find out the presence of ectoparasite that exists in the outside body part of the fish. Samples were collected from skin, fins, tail, and gills using native methods and observed under a microscope in the Division of Parasitology Laboratory, Faculty of Veterinary Medicine, Universitas Airlangga. The results of this study showed 86 samples positively infected by ectoparasite and 10 showed negative. The ectoparasites found in this study were Trichodina sp., Chilodonella sp., Ichthyophthirius multifillis, Gyrodactylus sp., and Dactylogyrus sp. The highest prevalence is Trichodina sp. and Dactylogyrus sp. The number of fish infested by ectoparasite is 89.56%, this is classified in the usual category. The highest prevalence occurs in infestations of Trichodina sp. i.e.72.91% which were contained in the 70 samples. While the lowest prevalence was in Gyrodactylus sp. by 8.32% in 8 fish samples. Double infections from two different ponds were 70% within 33 samples which were included in the usual category.

An undescribed relapsing fever group Borrelia species was detected in a male Haemaphysalis semermis tick infesting a rural cat in an indigenous population in Pahang National Park, Peninsular Malaysia. The 16 S rRNA gene sequence revealed close similarity of this variant to several undescribed Borrelia species and Borrelia theileri, with genetic distances ranging from 0.58 to 0.72%. Furthermore, the flaB, gyrB, and the concatenated 16 S rRNA + flaB + gyrB sequence analyses demonstrated that this variant is distinctly separated from multiple undescribed Borrelia species, Borrelia miyamotoi, and B. theileri, with genetic distances ranging from 3.41 to 7.00%. This study not only reports the first Borrelia found in H. semermis but also suggests that it forms a distinct clade within the relapsing fever group in Peninsular Malaysia. [ABSTRACT FROM AUTHOR]

Three new species of Jainus Mizelle, Kritzky & Crane, 1968, are described parasitizing the gill filaments of Triportheus angulatus (Spix & Agassiz) (Characiformes: Triportheidae), an omnivorous fish endemic to the Amazon River basin. Jainus iquitensisn. sp. is characterized by the morphology of the vagina, which is bell-shaped, with a canal as a sclerotized tube and the morphology of hook pair VII, which in the new species presents an inflated base, a characteristic not observed in other congeners. Jainus loretoensisn. sp. is unique among Jainus species due to the morphology of its Y-shaped ventral anchors, with an arrow-shaped superficial root and a finger-shaped deep root. Jainus sardinaen. sp. is characterized by presenting a slender, small J-shaped tube with a sigmoid accessory piece and a ventral anchor that is Y-shaped, with inconspicuous finger-shaped deep root and superficial root with rounded ending with a chin-shaped projection. These findings add three new species to the previously reported two Jainus species from Peru. [ABSTRACT FROM AUTHOR]

The crustaceans Argulus coregoni Thorell, 1864 were found on the body surface of brook trout Salmo trutta m. fario L., 1758 in the Velesa River (tributary of the Western Dvina River, Tver Oblast, Russia). This is the first finding of A. coregoni in the Western Dvina basin, which shows that this species can parasitize on specific hosts in the upper reaches of small rivers.

Leptus (Leptus) molochinus (C. L. Koch, 1837) (Trombidiformes: Erythraeidae) was collected as an ectoparasite on Ophion sp. (Hymenoptera: Ichneumonidae), Paederus fuscipes Curtis, 1826 (Coleoptera: Staphylinidae), Cicadella viridis (L. 1758) (Hemiptera: Cicadellidae), Peritrechus sp. (Hemiptera: Lygaeidae); the ectoparasitic mite, Solistrus mitrae Saboori, Ueckermann & van Harten, 2008 was also found on an undetermined ant species (Hymenoptera: Formicidae) from Guilan province, Iran. Additional morphometric data for L. (L.) molochinus larvae are provided. Solistrus mitrae is reported for the second time in the world. Ophion sp. (Hymenoptera: Ichneumonidae), P. fuscipes (Coleoptera: Staphylinidae), C. viridis (Hemiptera: Cicadellidae) and Peritrechus sp. (Hemiptera: Lygaeidae) are recorded as new host taxa for L. (L.) molochinus and unknown ant species is new host for S. mitrae.

Bat ectoparasitic ichnofossils can be useful to elucidate microbial mediation in mineralization processes of organic material, supplying valuable information on ancient parasitology and palaeoecology, among other topics. Rod-shaped features found in Cova des Pas de Vallgornera (Mallorca, Spain) are described for the first time. They are related to an ancient bat colony inhabiting the cave in the Early Pleistocene. These micro-morphologies are cylindrical in shape with sizes of a few hundred microns in length and less than one hundred microns in diameter. They are composed by a mash of microscopic calcite particles of different sizes and shapes, lying on deposits that contain phosphates and clay minerals. Some of these rodshaped morphologies are covered in microscopic crystals, whose mineralogy is composed mainly of calcite, associated with dolomite, quartz and clays, These deposits are interpreted as fecal droplets of bat ectoparasites (probably Nycteribiidae), that infested an ancient bat colony living in the cave before the collapse blocking of its natural entrances; from 2.4 Ma to present, the cave has remained sealed, preserving these deposits as a new ichnofossil related to invertebrate's coprolites. The observation of similar micro-structures in Cova de sa Guitarreta, another Mallorcan cave currently used as a bat roost, provided an opportunity to study a modern analogue. In this case, the rod-shaped structures consist of organic detritus with lenticular, concave forms (possibly resembling red blood cells) and minute mineral particles. These cylindrical features are therefore hypothesized to represent excreta from bloodsucking bat flies, with present-day deposits observed in Cova de sa Guitarreta and fossilized coprolites identified in Cova des Pas de Vallgornera. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ectoparasite Macrocheles subbadius induce modified time budgets even without possible infection. • Primary parasite encounter changes host feeding and resting upon secondary encounter. • Flies groom and increase their movements in the presence of mites. • Host resting frequency is decreased in the presence of mites. • Longer exposure to mites had a greater effect than infection on host behaviour. Parasites can indirectly impact hosts through non-consumptive effects (NCEs) via changes in behaviour, morphology, and/or physiology. These responses can be understood in terms of the ecology of fear (ectoparasites) or the ecology of disgust (endoparasites) framework. We tested the hypothesis that NCEs of parasite exposure (e.g., parasite avoidance and defense) trade off with other important behaviours such as feeding and resting. We predicted that when exposed to parasites (without infection), hosts will increase their defensive behaviors at the expense of feeding. We also posited that history of exposure (without infection), or previous infection would impact the expression of these NCEs. The study system involves a cactophilic fruit fly (Drosophila nigrospiracula) and a naturally occurring parasitic mite (Macrocheles subbadius). First, we assessed how prior mite exposure affected fly behaviour in response to current parasite exposure. Mite presence resulted in increased grooming and movement, but exposure history did not affect these behaviours. However, the interaction between previous and current exposure influenced host feeding and resting behaviours. We found that previously exposed flies increased feeding and decreased resting upon a secondary mite exposure. In a second experiment, we tested the role of infection history on current parasite exposure. Compared with naïve flies, previously infected flies were expected to increase defensive behaviours upon secondary exposure. Flies increased defensive and ambulatory behaviour in the presence of mites, and consequently less time was spent resting but feeding was unaffected. None of the behaviours measured were affected by previous infection status. In general, current parasite exposure resulted in NCEs. Moreover, our results showed that previous exposure (without infection) to parasites may have an even stronger effect upon secondary exposure than infection history. Our study highlights the importance of the ecology of fear and the role that exposure and infection history plays in generating NCEs of parasitism. [ABSTRACT FROM AUTHOR]

Introduction: The present study describes three new dactylogyrid species infecting the gill filaments of cichlid fishes (Cichliformes: Cichlidae) from the Amazon basin, Peru: Sciadicleithrum amazoniensis n. sp. on Biotodoma cupido (Heckel, 1840), and Sciadicleithrum feliciajaramae n. sp. and Sciadicleithrum souzatecci n. sp. on Bujurquina peregrinabunda Kullander, 1986. Materials and methods: Some monogeneans were stained with Gomori's trichrome and mounted in Canada Balsam to determine internal soft structures. Others were cleared in Hoyer's medium for the study of sclerotized structures. Drawings were made using a drawing tube and a microprojector. Results: Sciadicleithrum amazoniensis n. sp. is characterized by the presence of a male copulatory organ (MCO) with a coil of approximately 2 counterclockwise rings, an accessory piece articulated to base of the MCO with an expanded proximal end and a bifurcated distal end, and a sinistral vaginal aperture. Sciadicleithrum feliciajaramae n. sp. can be differentiated from all its congeners by its J-shaped MCO with about half a counterclockwise loop and a rod-shaped accessory piece articulated to the base of the MCO, with the distal end bent. Sciadicleithrum souzatecci n. sp. differs from all other members of Sciadicleithrum by having an elongated MCO with about a clockwise loop and a funnel-shaped base. Additionally, Sciadicleithrum souzatecci n. sp. is characterized by its weakly sclerotized, C-shaped accessory piece with a robust middle process. Conclusions: Present findings are added to the other 26 species previously known in Sciadicleithrum.This is the first data on the parasites of B. peregrinabunda. [ABSTRACT FROM AUTHOR]

Pike perch were transferred from an over-wintering net cage into recirculating aquaculture systems (RAS). Within a 21-day period, it was examined whether or not ectoparasites, here specifically a representative of the family of Trichodinidae that were naturally present on the fish, could be reduced or even eliminated from the fish by means of sodium chloride treatment (3 and 6 g NaCl/L). Despite a significant reduction in trichodinid density, the application of 3 g NaCl/L proved to be insufficient to eliminate all trichodinids during the 21-day trial. However, under RAS conditions, a continuous 21-day exposure to 6 g NaCl/L completely eliminated the trichodinids on the fish. Based on the observations of the composition of the trichodinid density, it is recommended to screen fish for ectoparasites on multiple body sites. In conclusion, NaCl can be considered an effective and low-cost therapeutic in pike perch aquaculture against trichodiniasis. [ABSTRACT FROM AUTHOR]

Simple Summary: The greater wax moth, Galleria mellonella, is a significant pest in apiculture. This investigation explores the individual and combined effects of the ectoparasite Bracon hebetor (B.h.) and the entomopathogenic nematode Steinernema carpocapsae (S.c.) on G. mellonella larvae. We found that control larvae exhibited higher glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities compared to those treated with B.h., S.c., or the B.h. + S.c. combination. Conversely, malondialdehyde (MDA) levels displayed an opposite trend. Superoxide dismutase (SOD) activity was reduced in the B.h. and S.c. groups but significantly higher in the combined treatment. Cytochrome P450 activity increased in response to parasitism by B. hebetor. The Annexin V-FITC assay revealed decreased cell viability in parasitized groups (B.h. 79.4%, S.c. 77.3%, B.h. + S.c. 70.1%) compared to controls. DNA damage analysis demonstrated significant differences between groups, and SEM observations confirmed severe cuticle abnormalities or malformations in G. mellonella larvae. The greater wax moth, Galleria mellonella, is a significant pest in apiculture and a well-established model organism for immunological and ecotoxicological studies. This investigation explores the individual and combined effects of the ectoparasite Bracon hebetor (B.h.) and the entomopathogenic nematode Steinernema carpocapsae (S.c.) on G. mellonella larvae. We evaluated the activity of oxidative stress enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), malondialdehyde (MDA) levels, cytochrome P450 activity, cell viability using Annexin V-FITC, DNA damage via comet assay, and larval morphology through scanning electron microscopy (SEM). Control larvae exhibited higher GPx and GST activities compared to those treated with B.h., S.c., or the B.h. + S.c. combination. Conversely, MDA levels displayed the opposite trend. SOD activity was reduced in the B.h. and S.c. groups but significantly higher in the combined treatment. Cytochrome P450 activity increased in response to parasitism by B. hebetor. The Annexin V-FITC assay revealed decreased cell viability in parasitized groups (B.h. 79.4%, S.c. 77.3%, B.h. + S.c. 70.1%) compared to controls. DNA damage analysis demonstrated significant differences between groups, and SEM observations confirmed severe cuticle abnormalities or malformations in G. mellonella larvae. These findings highlight the complex interactions between B. hebetor, S. carpocapsae, and their host, G. mellonella. Additionally, they illuminate the intricate physiological responses triggered within the host larvae. [ABSTRACT FROM AUTHOR]

An updated phylogenomic tree of the Nudiviridae is presented, including 49 species, proposing two genera associated with ectoparasitic insects. Evolution of the family Nudiviridae is estimated to have occurred in the mid-Devonian, matching the timeline of the insect's evolution. All the crustacean-infecting nudiviruses have likely emerged from a single common ancestor (~143 million years ago), perhaps transmitted to Jurassic crustaceans by an insect host. The Nudiviridae have a proclivity for ectoparasitic arthropods (i.e., lice and fleas), linked to multiple diversification events in the Triassic (early Betanudivirinae split), Jurassic (involving ectoparasitic hosts of alphanudiviruses), and Cretaceous periods (Zeta/Etanudivirus diversification). Nudiviruses inhabit various geographical and climatic zones, including members from subpolar habitats. The nudiviruses (family: Nudiviridae) are large double-stranded DNA (dsDNA) viruses that infect insects and crustaceans, and have most recently been identified from ectoparasitic members (fleas and lice). This virus family was created in 2014 and has since been expanded via the discovery of multiple novel viral candidates or accepted members, sparking the need for a new taxonomic and evolutionary overview. Using current information (including data from public databases), we construct a new comprehensive phylogeny, encompassing 49 different nudiviruses. We use this novel phylogeny to propose a new taxonomic structure of the Nudiviridae by suggesting two new viral genera (Zetanudivirus and Etanudivirus), from ectoparasitic lice. We detail novel emerging relationships between nudiviruses and their hosts, considering their evolutionary history and ecological role. [ABSTRACT FROM AUTHOR]

A new larval species Eutrombidium keralaensissp. nov. (Acari: Microtrombidiidae: Eutrombidiinae) parasitizing Teleogryllus sp. (Orthoptera: Gryllidae: Gryllinae) is described and illustrated for the first time from Kerala, India. This species belongs to the species group with large and fully separate lobed lateral coxalae I, coxalae II and III. [ABSTRACT FROM AUTHOR]

This study aimed to identify the type of ectoparasite in the adult tilapia. For this study, 20 specimens of the tilapia fish, with an average weight of 247.68± 69.47g, were collected. The fish samples were placed in the rearing unit at the Higher Institute of Maritime Fisheries, Agadir, Morocco. The study was conducted from October 2023 to April 2024. 16 samples were examined in the physiology and oceanography laboratory. The samples were eviscerated to detect the parasite. The fish had ectoparasites in the gills, eyes, and on scales. The parasite was identified as Dactylogyrus sp. and was found only on the tilapia’s scales and in its gills. [ABSTRACT FROM AUTHOR]

Leptus (Leptus) molochinus (C. L. Koch, 1837) (Trombidiformes: Erythraeidae) was collected as an ectoparasite on Ophion sp. (Hymenoptera: Ichneumonidae), Paederus fuscipes Curtis, 1826 (Coleoptera: Staphylinidae), Cicadella viridis (L. 1758) (Hemiptera: Cicadellidae), Peritrechus sp. (Hemiptera: Lygaeidae); the ectoparasitic mite, Solistrus mitrae Saboori, Ueckermann & van Harten, 2008 was also found on an undetermined ant species (Hymenoptera: Formicidae) from Guilan province, Iran. Additional morphometric data for L. (L.) molochinus larvae are provided. Solistrus mitrae is reported for the second time in the world. Ophion sp. (Hymenoptera: Ichneumonidae), P. fuscipes (Coleoptera: Staphylinidae), C. viridis (Hemiptera: Cicadellidae) and Peritrechus sp. (Hemiptera: Lygaeidae) are recorded as new host taxa for L. (L.) molochinus and unknown ant species is new host for S. mitrae. [ABSTRACT FROM AUTHOR]

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A new species of tiphiid wasp, namely, Tiphia (Tiphia) andhraensis Hanima & Girish Kumar sp. nov. is described from Andhra Pradesh in the southern coastal region of India based on the female holotype. The new species is described, illustrated and compared with congeneric species. The diagnostic character of the new species is the presence of a strong, median longitudinal carina on posterior side of propodeum. The new species described here was collected from the Mudasarlova reservoir area of the Visakhapatnam district of Andhra Pradesh. The previous key to the species of Tiphia from the Indian subcontinent is modified to accommodate the new species. This new species is the first tiphiid wasp described from Andhra Pradesh.

Abstract Background The chicken body louse is an obligate ectoparasite of domestic chickens. Chicken body lice feed on feathers, and infestation with this louse is linked to decreases in egg production, hen weight, and feed conversion efficiency. However, it is unknown how chicken body lice impact egg-laying chickens in cage-free environments. Welfare and behavior metrics were collected from flocks of egg-laying chickens either infested with chicken body lice or left uninfested. Methods In two trials, two flocks of cage-free commercial egg-laying chickens were infested with chicken body lice or maintained as uninfested controls. At three timepoints, behavior and welfare of all chickens was measured. On-animal sensors were used to quantify pecking, preening, and dustbathing behavior. Other animal-based welfare metrics included recording comb wounds and skin lesions. Results Birds infested with chicken body lice exhibited significantly more preening behaviors than uninfested birds, even at low louse levels. Moderate or severe skin lesions were detected on birds that were moderately infested with chicken body lice while skin lesions were never detected on uninfested birds. Conclusions The welfare of chickens was impacted by the chicken body louse, a chewing louse that primarily feather feeds. Evidence of skin lesions on infested birds suggests that lice may cause more damage to birds than previously thought, and further evaluation of louse economic damage is necessary. Graphical Abstract

Abstract Background Exotic and ornamental fish are highly popular companion animals resulting in a significant transcontinental trade of fish, invertebrates and aquatic plants. A major issue is the diseases associated with these organisms, as they have a major impact on health of the fish in both public and private household aquaria. A secondary issue is the trade with these products, which potentially may expand the distribution area and spread a range of diseases to new habitats. Results We here describe how Poecilia reticulata (guppy), produced in a private household aquarium, were invaded by cercariae of an exotic trematode released by imported Melanoides tuberculata snails. The fish presented with severe clinical signs (tremor, flashing, scraping of body against objects). A standard parasitological examination and morphometric identification showed scale pocket infections with a digenean trematode species within the genus Transversotrema. Molecular identification by PCR, sequencing and phylogenetic analyses of a 2646 bp sequence encoding ribosomal RNA (partial 18 S, ITS1, 5.8 S, ITS2, partial 28 S) was performed. The 1107 bp sequence of mitochondrial DNA (cox1) showed that the parasite differed from previously described Transversotrema species in M. tuberculata. Morphometrics of adult and larval specimens of this isolate also differed from previously described freshwater species within the genus. The new species was described and is named after Copenhagen, for its geographic origin. Conclusions The genus Transversotrema comprises a range of species, adapted to a microhabitat in scalepockets of teleosts. A combination of morphological and molecular characterization techniques has been shown to provide a good differentiation between species. The fish were not purchased from a pet shop but produced in the home aquarium. This indicated that an infection pressure existed in the aquarium, where the source of infection was found to be exotic intermediate host snails M. tuberculata, which originally were imported and purchased from a pet shop. The potential spread of fish diseases associated with trade of fish and snails to new geographic regions, where climate conditions are favourable, is discussed.

Spiny lobster, a fishery commodity with important economic value, is often infested by Octolasmis sp. on their bodies, which causes stress conditions that lead to death. This study aimed to determine the anatomical pathology and hemolymph profile of spiny lobster infested with Octolasmis sp. in bottom cages. The method used was an observation, where 30 lobsters (weight 112.44 ± 24.63 g) were carried out in June–July 2022 at the Pesona Bahari Wongsorejo, Banyuwangi. Hemolymph profile and anatomical pathology data were analyzed, respectively, using the Independent T-Test and Kruskal-Wallis test (α = 95%). The results based on scoring data showed a very significant difference between infected and healthy lobsters (p < 0.01), characterized by the occurrence of tail flakes, lesions on the carapace, gill melanization, and the appearance of ulcers on the ventral abdomen. A very significant change occurred in the hemolymph profile of infected lobsters compared to healthy lobsters (p < 0.01). Total hemocyte count increased with high concentrations of granular cells, respectively 22.1–37.8 ´x 106 cells/mL and 63.75–64.5%, along with lobster damage, while hyaline cells decreased. This study showed that there was a change in anatomic pathology and hemolymph profile between infected and healthy lobsters.

The Asian leaf turtle (Cyclemys dentata) is a freshwater turtle species found in select Southeast Asian countries, including the Philippines. Our understanding of C. dentata's ecology in the Philippines is not yet fully understood and documented, and this is derived only from a few studies. In this paper, we present our single-event observation of an ectoparasite interaction between C. dentata and the Asian turtle tick (Amblyomma geoemydae) from Sitio Malbato, Barangay Bintuan Coron, Palawan. Our discovery serves as the second documented instance of this ectoparasite on C. dentata in the Philippines, hence extending its known distribution outside mainland Palawan. This finding contributes to the limited understanding of C. dentata's ecology and underscores the need for further field-based observations, which are crucial for their research and conservation. [ABSTRACT FROM AUTHOR]

Fish ectoparasites are one of the pathogens groups that pose great concern to the aquaculture industry. The dinoflagellate Amyloodinium ocellatum is responsible for amyloodiniosis, a parasitological disease with a strong economic impact in temperate and warm water aquaculture, mainly in earthen pond semi‐intensive systems. Amyloodiniosis represents one of the most important bottlenecks for aquaculture and, with the predictable expansion of the area of influence of this parasite to higher latitudes due to global warming it might also be a threat to other aquaculture species that are not yet parasitized by A. ocellatum. This review made a compilation of the existing knowledge about this parasite and the disease associated with it. It was noticed that, except from the life cycle characterisation, detection methods, histopathological analysis, and treatments, there are still a lot of areas that need a further investment in research. Areas like parasite–host interactions, epidemiological models, taxonomy, host physiological responses to parasitism, and genome sequencing, amongst others, can contribute to a better understanding of this disease. These proposed approaches and routes of investigation will enhance and contribute to a more standardised knowledge, creating the opportunity for a better understanding of amyloodiniosis impacts on fish and contributing for the development of new tools against A. ocellatum, that may reduce fish mortality in aquaculture production due to amyloodiniosis outbreaks. [ABSTRACT FROM AUTHOR]

The avian vampire fly Philornis downsi (Dodge & Aitken) (Diptera: Muscidae) is native to continental South America and the Caribbean, but invasive in the Galapagos Archipelago. The larvae of P. downsi feed on the blood and tissues of the nestlings of 75% of the small land bird species that are endemic or native to Galapagos, causing high in-nest mortality and severe population declines in some species. Efficient trapping techniques are vital to safeguarding these birds in the short term as well as for monitoring fly populations, but basic information about the ecology of the fly is still needed to help develop a species-appropriate trapping method. In this study, we used a novel trapping regime with a vertical distribution to make inferences about P. downsi 's behavioral and spatial ecology and to optimize trap catch. Our results showed that male and female P. downsi were trapped in greater numbers below the canopy (3.1–7.5 m), lower down than other commonly caught insect species (5.1–11.5 m). Notably, the effect of trap height remained consistent across seasons and different weather conditions. These findings suggest that P. downsi tend to move at heights where their hosts nest (at or below the canopy) and do not spend time above the canopy. This also makes it unlikely that strategies such as hill-topping or aerial swarming are being used to locate mates. As such, trapping and control efforts should be focused below the canopy in forests with similar canopy heights to effectively capture P. downsi and reduce bycatch of other insects. [ABSTRACT FROM AUTHOR]

Purpose : Rhipicephalus (Boophilus) microplus is one the most significant ectoparasite in cattle farming in tropical and subtropical regions, causing problems to livestock health worldwide. The control of this ectoparasite primarily relies on the use of synthetic acaricides. However, the emergence of acaricide resistance has stimulated the search for new control alternatives, including phytocompounds with acaricidal and insecticidal potential. The aim of this study was to evaluate the acaricidal potential of Lavandula dentata essential oil against the engorged females of R. (B.) microplus. Methods: Engorged females were obtained from infested bovines in dairy farms in Pernambuco, Brazil. L. dentata essential oil was extracted, and adult immersion test assays were performed using the following oil concentrations: 0.2%, 0.4%, 0.6%, 0.8%, and 1%. Results : L. dentata essential oil at a concentration of 1% was lethal to all engorged females, and concentrations of 0.6% and 0.8% caused mortality of 98.6% and 99.1%, respectively. These concentrations disrupted the reproductive capacity of engorged females, reducing oviposition by more than 90% and preventing egg hatching by over 87%. Conclusion: The data revealed that L. dentata essential oil possesses effective pharmacological properties against R. (B.) microplus and could be used for tick control following in vivo evaluation, thus contributing to mitigating the negative impacts of synthetic acaricide use. [ABSTRACT FROM AUTHOR]

An analysis of ectoparasite infestations in Champsocephalus gunnari at South Orkney Islands, Antarctica, was performed, which revealed the prevalence, mean abundance, and mean intensity of the two species of parasites collected. The parasites' preference for parts of the infested host fish was also investigated. The host–parasite trophic relationship was further examined using stable carbon and nitrogen isotopic analysis. The results showed that Eubrachiella antarctica was more inclined to parasitize the fins of C. gunnari. The carbon isotope ratio (δ13C) of the host was negatively correlated with the values for carbon isotopic discrimination (Δδ13C) between host and E. antarctica. The relationship between E. antarctica and C. gunnar is considered "parasitic" because E. antarctica has a higher trophic level than that of host C. gunnari, while Trulliobdella capitis may be a carrier parasite of C. gunnari or show a "symbiotic" relationship with it. The ecological niche spaces of the three species do not overlap, indicating the existence of specific trophic niches in the marine food web. [ABSTRACT FROM AUTHOR]

Objective. To analyze histological and immunological changes in the Pacific white snook (PWS) Centropomus viridis during primary infection and re-infection with the monogenean Rhabdosynochus viridisi. Materials and methods. Samplings were performed at three timepoints (0,1, and 2). Histological alterations in gills were evaluated by the severity degree and the degree of tissue change. RT-qPCR assays were developed to investigate the expression of il1B, il8, il10, il12, il17, igM, igT, ifnγ, tnfα, tbet, hsp70, foxp3a, stat4, and cmip in gills and head kidney. Results. The prevalence of infection was 100% in challenged fish. During the primary infection, the mean intensity was 152 parasites per fish at Time 1 and 94 at Time 2, while in the reinfection, it was 367 parasites at Time 1 and 129 at Time 2. Histological analysis of gills showed fusion of the secondary lamellae, hyperplasia, infiltration of mononuclear inflammatory cells, and increase of chloride cells in both primary infections and reinfections. Only the expression of cmip in gills at Time 1 was significantly higher in reinfections than in primary infections, and the expression of il12β showed a fold-change value >100 in head kidney at Time 2 in primary infections. Conclusions. The monogenean R. viridisi may cause histological alteration in its fish host. As showed by the decrease of the intensity of infection from Time 1 to Time 2, it seems that the PWS is able to combat R. viridisi; however, our immunological analysis did not reveal strong evidence of a possible mechanism. [ABSTRACT FROM AUTHOR]

Background: Exotic and ornamental fish are highly popular companion animals resulting in a significant transcontinental trade of fish, invertebrates and aquatic plants. A major issue is the diseases associated with these organisms, as they have a major impact on health of the fish in both public and private household aquaria. A secondary issue is the trade with these products, which potentially may expand the distribution area and spread a range of diseases to new habitats. Results: We here describe how Poecilia reticulata (guppy), produced in a private household aquarium, were invaded by cercariae of an exotic trematode released by imported Melanoides tuberculata snails. The fish presented with severe clinical signs (tremor, flashing, scraping of body against objects). A standard parasitological examination and morphometric identification showed scale pocket infections with a digenean trematode species within the genus Transversotrema. Molecular identification by PCR, sequencing and phylogenetic analyses of a 2646 bp sequence encoding ribosomal RNA (partial 18 S, ITS1, 5.8 S, ITS2, partial 28 S) was performed. The 1107 bp sequence of mitochondrial DNA (cox1) showed that the parasite differed from previously described Transversotrema species in M. tuberculata. Morphometrics of adult and larval specimens of this isolate also differed from previously described freshwater species within the genus. The new species was described and is named after Copenhagen, for its geographic origin. Conclusions: The genus Transversotrema comprises a range of species, adapted to a microhabitat in scalepockets of teleosts. A combination of morphological and molecular characterization techniques has been shown to provide a good differentiation between species. The fish were not purchased from a pet shop but produced in the home aquarium. This indicated that an infection pressure existed in the aquarium, where the source of infection was found to be exotic intermediate host snails M. tuberculata, which originally were imported and purchased from a pet shop. The potential spread of fish diseases associated with trade of fish and snails to new geographic regions, where climate conditions are favourable, is discussed. [ABSTRACT FROM AUTHOR]

Chorioptic mange is the most common type of bovine mange in central Europe, affecting mainly housed dairy cattle. Until 1976, when Chorioptes texanus were described for the first time from mangy cattle in Brazil, bovine chorioptic mange was thought to be caused only by C. bovis mites. In Europe, C. texanus parasitism in cattle was for the first time reported in Germany in 1998. Following the repeated diagnosis of C. texanus mites in skin scrapings from local cattle in recent years, scrapings from cattle that were clinically suspicious for chorioptic mange were requested and provided during the years from 2019 to 2022 from Austria, France, Germany, and Switzerland (from 6, 17, 28, and 7 farms, respectively) and from dairy cows of 1 farm in Canada. Mites were isolated from the scrapings, cleared, and microscopically identified based on their morphology. Examination of scrapings revealed the presence of C. texanus in the cattle from 2 farms in Austria, 13 farms in France, 7 farms in Germany, 1 farm in Switzerland, and in the specimens from Canada. Chorioptes bovis mites were recovered only in scrapings from 5 farms in Germany and Psoroptes ovis mites in scrapings of cattle from 2 farms in France. The scrapings did not reveal co-infestations of C. bovis and C. texanus or of Chorioptes species and P. ovis. The records of C. texanus from Austria, France, Switzerland, and Canada constitute the first descriptions of this mite species in these countries. Although this investigation was based on an opportunistic collection of the material and was of small extent, the results suggest a widespread occurrence of C. texanus in central Europe and may emphasize the need for studies to closely investigate the nature of the causative agents of chorioptic mange in cattle and other hosts. [ABSTRACT FROM AUTHOR]

Spinturnicid mites are ectoparasites exclusively of bats. Herein, we provide a comprehensive catalogue of spinturnicid species recorded in Brazil focusing on their distribution nationwide. This catalogue listed 16 spinturnicid species into four different genera, and a key for the genera recorded in Brazil. Also, it provides new locality records for four species: Cameronieta almaensis Almeida, Gettinger and Gardner, Periglischrus acutisternus Machado-Allison, Periglischrus caligus Kolenati, and Periglischrus iheringi Oudemans. Additionally, this study includes a detailed discussion on the host-specificity and molecular data of these mites. [ABSTRACT FROM AUTHOR]

A new species of tiphiid wasp, namely, Tiphia (Tiphia) andhraensis Hanima & Girish Kumar sp. nov. is described from Andhra Pradesh in the southern coastal region of India based on the female holotype. The new species is described, illustrated and compared with congeneric species. The diagnostic character of the new species is the presence of a strong, median longitudinal carina on posterior side of propodeum. The new species described here was collected from the Mudasarlova reservoir area of the Visakhapatnam district of Andhra Pradesh. The previous key to the species of Tiphia from the Indian subcontinent is modified to accommodate the new species. This new species is the first tiphiid wasp described from Andhra Pradesh. [ABSTRACT FROM AUTHOR]

Spiny lobster, a fishery commodity with important economic value, is often infested by Octolasmis sp. on their bodies, which causes stress conditions that lead to death. This study aimed to determine the anatomical pathology and hemolymph profile of spiny lobster infested with Octolasmis sp. in bottom cages. The method used was an observation, where 30 lobsters (weight 112.44 ± 24.63 g) were carried out in June–July 2022 at the Pesona Bahari Wongsorejo, Banyuwangi. Hemolymph profile and anatomical pathology data were analyzed, respectively, using the Independent T-Test and Kruskal-Wallis test (α = 95%). The results based on scoring data showed a very significant difference between infected and healthy lobsters (p < 0.01), characterized by the occurrence of tail flakes, lesions on the carapace, gill melanization, and the appearance of ulcers on the ventral abdomen. A very significant change occurred in the hemolymph profile of infected lobsters compared to healthy lobsters (p < 0.01). Total hemocyte count increased with high concentrations of granular cells, respectively 22.1–37.8 x 106 cells/mL and 63.75–64.5%, along with lobster damage, while hyaline cells decreased. This study showed that there was a change in anatomic pathology and hemolymph profile between infected and healthy lobsters. [ABSTRACT FROM AUTHOR]

Objective. To analyze histological and immunological changes in the Pacific white snook (PWS) Centropomus viridis during primary infection and re-infection with the monogenean Rhabdosynochus viridisi. Materials and methods. Samplings were performed at three timepoints (0,1, and 2). Histological alterations in gills were evaluated by the severity degree and the degree of tissue change. RT-qPCR assays were developed to investigate the expression of il1B, il8, il10, il12, il17, igM, igT, ifnγ, tnfα, tbet, hsp70, foxp3a, stat4, and cmip in gills and head kidney. Results. The prevalence of infection was 100% in challenged fish. During the primary infection, the mean intensity was 152 parasites per fish at Time 1 and 94 at Time 2, while in the reinfection, it was 367 parasites at Time 1 and 129 at Time 2. Histological analysis of gills showed fusion of the secondary lamellae, hyperplasia, infiltration of mononuclear inflammatory cells, and increase of chloride cells in both primary infections and reinfections. Only the expression of cmip in gills at Time 1 was significantly higher in reinfections than in primary infections, and the expression of il12β showed a fold-change value >100 in head kidney at Time 2 in primary infections. Conclusions. The monogenean R. viridisi may cause histological alteration in its fish host. As showed by the decrease of the intensity of infection from Time 1 to Time 2, it seems that the PWS is able to combat R. viridisi; however, our immunological analysis did not reveal strong evidence of a possible mechanism.

Chiggers (chigger mites) are a group of tiny arthropods, and they are the exclusive vector of Orientia tsutsugamushi (Ot), the causative agent of scrub typhus (tsutsugamushi disease). Dehong Prefecture in Yunnan Province of southwest China is located on the China–Myanmar border and is an important focus of scrub typhus. Based on the field surveys in Dehong between 2008 and 2022, the present paper reports the infestation and ecological distribution of chiggers on the body surface of rodents and other sympatric small mammals (shrews, tree shrews, etc.) in the region for the first time. The constituent ratio (Cr), prevalence (PM), mean abundance (MA), and mean intensity (MI) were routinely calculated to reflect the infestation of small-mammal hosts with chiggers. Additionally, the species richness (S), Shannon–Wiener diversity index (H), Simpson dominance index (D), and Pielou’s evenness index (E) were calculated to illustrate the chigger community structure. Preston’s log-normal model was used to fit the theoretical curve of species abundance distribution, and the Chao 1 formula was used to roughly estimate the expected total species. The “corrplot” package in R software (Version 4.3.1) was used to analyze interspecific relationships, and the online drawing software was used to create a chord diagram to visualize the host–chigger associations. From 1760 small-mammal hosts, a total of 9309 chiggers were identified as belonging to 1 family, 16 genera, and 117 species, with high species diversity. The dominant chigger species were Leptotrombidium deliense, Walchia ewingi, and Gahrliepia longipedalis, with a total Cr = 47.65% (4436/9309), among which L. deliense is the most important vector of Ot in China. The overall infestation indexes (PM, MA, and MI) and community parameters (S, H, and E) of chiggers in the mountainous areas and outdoors were higher than those in the flatland areas and indoors, with an obvious environmental heterogeneity. Leptotrombidium deliense was the dominant species in the flatland and indoors, while G. longipedalis was the prevalent species in the mountainous and outdoor areas. The species abundance distribution of the chigger community conformed to log-normal distribution with the theoretical curve equation: S(R)′=28e−[0.23(R−0)]2, indicating the existence of many rare species and only a few dominant species in the community. The expected total number of chigger species was roughly estimated to be 147 species, 30 more than the 117 species actually collected, suggesting that some uncommon species may have been missed in the sampling survey. The host–parasite association analysis revealed that one host species can harbor different chigger species, and one chigger species can parasitize different host species with low host specificity. A positive or negative correlation existed among different chigger species, indicating a cooperative or competitive interspecific relationship. The species diversity of chiggers is high in Dehong on the China–Myanmar border, and a large host sample is recommended to find more uncommon species. There is an obvious environmental heterogeneity of the chigger community, with different species diversity and dominant species in different environments. The low host specificity of chiggers and the occurrence of a large number of L. deliense in Dehong, especially in flatland areas and indoors, would increase the risk of persistent transmission of scrub typhus in the region.

In this study, a new species of Monogenoidea, Cosmetocleithrum amazonensis n. sp., parasitizing the gills of the silurid Auchenipterichthys coracoideus (Eigenmann & Allen, 1942), is documented. Cosmetocleithrum amazonensis n. sp. is distinguished from all other congeners by possessing an elongated, sclerotized, and sinuous male copulatory organ (MCO) with poorly defined spirals, a sclerotized border at the base, and the distal region supported by the accessory piece. The accessory piece is a single, robust, and non-articulated plate with the MCO. This study presents the third record of a Monogenoidea species in an Auchenipteridae (Siluriformes) host from Peru. [ABSTRACT FROM AUTHOR]

Rodent populations often undergo large, regular fluctuations. We studied immunological condition and physiological stress in the common vole and how it varied with environmental factors linked with population fluctuations, namely flea and Francisella tularensis (the bacterium causing tularemia) prevalence. We used two leukocyte indices, neutrophil-to-lymphocyte ratio (N:L) and proportion of eosinophils, as physiological long-term stress indicators, and measured levels of immunoglobulins (Ig) as a generic index of immunological condition. Leukocyte indices showed a hump-shaped relationship with Ig levels, consistent with an interdependence between physiological stress and immunological condition. N:L was negatively associated with vole density only in males. Eosinophil proportion was explained by the interaction between flea burden and tularemia prevalence, with highest levels in flea-infested voles also infected with tularemia. Ig levels did not vary with sex or flea prevalence but increased in tularemia-infected voles. When Ig levels were included as covariates in our models, the associations between leukocyte indices and environmental factors remained significant. Results suggest sex-specific associations between physiological stress and population density, and an influence of tularemia infection depending on ectoparasite load. We recommend using immunological parameters complementarily to leukocyte indices when studying physiological stress and infection dynamics in wild populations. [ABSTRACT FROM AUTHOR]

Birds have a diverse community of “permanent” arthropods that complete their entire life cycle on the body of the host. Because some of these arthropods are parasites that reduce host fitness, birds control them by grooming, which consists of preening with the beak and scratching with the feet. Although preening is the primary component of grooming, scratching is essential for controlling arthropods on the head and neck, which cannot be preened. Several unrelated groups of birds have evolved comb-like pectinate claws on the middle toenail of each foot. We tested the role of these claws in the control of arthropods by experimentally removing teeth from the claws of captive western cattle egrets (Bubulcus ibis) infested with chewing lice (Insecta: Phthiraptera), feather mites (Acari: Sarcoptiformes), and nasal mites (Acari: Mesostigmata). After a period of 4 mo, we compared the abundance of arthropods on experimental birds to that of control birds with intact teeth. We used video to quantify the grooming rates of the captive birds, which groomed twice as much as wild birds. Experimental and control birds did not differ significantly in grooming time. Both groups virtually eradicated the chewing lice, but not feather mites or nasal mites. We found no support for the hypothesis that pectinate claws increase the efficiency of arthropod control by grooming. Experiments with wild birds are needed to test the hypothesis further under conditions in which birds devote less time to grooming. [ABSTRACT FROM AUTHOR]

Eutrombicula alfreddugesi (Oudemans, 1910) is the most common chigger parasitic on humans and widely distributed throughout the Americas. Examination of the type specimens revealed differences from those of the original description and subsequent redescriptions. A detailed redescription based on an examination of the type specimens of E. alfreddugesi is provided and illustrated with micrographs to aid in identification, as well as designating a lectotype and a paralectotype for this species. The distribution of E. alfreddugesi may be much more restricted than what has been reported in the literature. [ABSTRACT FROM AUTHOR]