Evolutionary adaptations in four hippoboscid fly species belonging to three different subfamilies

First report of Lipoptena axis Maa, 1965, from captive cervids in Thailand, based on morphological and molecular data

Deer louse flies (Lipoptena spp.) are hematophagous ectoparasites of cervids. The genus Lipoptena comprises 32 species, some of which are of veterinary importance as vectors of various pathogens, and are also known to attack human hosts. Recently, deer louse flies have been observed during annual checkups of captive cervids at Khon Kaen Zoo in Khon Kaen, Thailand. However, data on their specific identity and prevalence remain limited. This study aims to identify louse fly samples from captive cervids at Khon Kaen Zoo using morphological and molecular analyses. A total of 60 louse flies were collected from 17 captive cervids and identified based on their morphology. Major morphological characteristics, including mesothoracic bristle patterns, abdominal tergal plate bristles, and terminalia structure indicated that the Khon Kaen louse fly is Lipoptena axis Maa, 1965. Phylogenetic analysis of sequences from a portion of the mitochondrial cytochrome c oxidase subunit I (COI) gene was performed, which confirmed that L. axis of this study belongs to the cervi group, which is distinct from other groups of Lipoptena species. This study represents the first report of L. axis in Thailand. We provide an updated taxonomic key for the identification of Lipoptena species in the cervi group.

Morphology of the wings and attachment apparatus in the evolution of the family Hippoboscidae (Diptera)

Using a complex analysis of the molecular genetics, morphological, and ecological characteristics of Hippoboscidae flies, the phylogenetic structure and trends in the evolution of morphological characters that contribute to the ectoparasitic lifestyle of hippoboscid flies of the north of Eurasia were studied for the first time. The research was carried out on 26 Palearctic species from 10 genera. The analysis of molecular phylogeny revealed the levels of clustering of the family with the species predominantly parasitizing mammals or birds, the time of cluster formation, and the divergence of species in the Palearctic conditions. An independent adaptation to birds occurred in the genera Icosta, Pseudolynchia, Ornithoica, and others. Bird parasites are characterized by bifid tarsal claws, long hooks on pulvilli, and long empodium setae (except genus Ornithoica). Mammalian parasites are characterized by simple tarsal claws, short lobes of hooks on pulvilli, and zones on empodium with short setae. Specialization in empodium and pulvillus morphotypes and wing reduction are higher diverged in mammalian parasites than in bird parasites. The decrease of flight ability and wing reduction independently arose in different subfamilies of Hippoboscidae flies. Our results assume that the tribe Ornithomyini is a paraphyletic group, since, according to the complex of morphological features, the genus Ornithoica can be considered a separate lineage of evolution.

Hippobosca equina L. (Hippoboscidae: Hippobosca)-An Old Enemy as an Emerging Threat in the Palearctic Zone

Arthropods of the Hippoboscoidea superfamily are parasites of animals from various systematic groups. Mass appearances of these insects and their attacks on people are increasingly being recorded. Their parasitism has a negative effect on host well-being, as it causes feelings of agitation and irritation as well as skin itching and damage. It may result in weight loss and development of diseases in the long-term perspective. Parasites can be a potential epidemiological threat for their hosts as well. One of such parasites is a cosmopolitan species of the Hippoboscinae subfamily-Hippobosca equina. Studies have confirmed the presence of Corynebacterium pseudotuberculosis equi, Bartonella spp., and Anaplasma spp. in the organism of these insects. The frequency of anaphylactic reactions caused by H. equina attacks has been increasing. The aim of the present paper was to summarize the up-to-date knowledge of Hippobosca equina Linnaeus, 1758 due to its significance in medical and veterinary sciences as a potential vector of pathogens. Given the increasing expansion of ectoparasites, mainly related to climate change, ensuring animal welfare and human health is a priority.

Low host specificity of Hippobosca equina infestation in different domestic animals and pigeon

This study aimed to highlight the low host specificity of Hippobosca equina (H. equina) that poses a danger in diseases transmission between different animal species as well as, identification of the collected flies using light microscope and molecular characterization of H. equina in Egypt. Two hundred and forty flies were collected weekly from different animal species from El-Faiyum, Al Qalyubia and Kafr El-Sheikh Governorates, Egypt at the period from May to September of 2020. Insects were phenotypically and genetically identified then classified into 170 (70.8%) males and 70 (29.2%) females. The highest prevalence of H. equina was noticed from mid-June to the end of August. The sequencing of COI gene of five H. equina fly collected from different hosts as (horse, pigeon, cattle, buffalo, and donkey) were submitted to the GenBank under the accession numbers of MZ452239, MZ452240, MZ461943, MZ461944, and MZ461945, respectively. For insect infestation control, fipronil and deltamethrin is monthly sprayed for animals, birds and their circumference give a best result in our control study in the field. Deltamethrin showed a success in the elimination process and control measures of external parasites of pigeon.

Antennal Morphology and Fine Structure of Flagellar Sensilla in Hippoboscid Flies with Special Reference to Lipoptena fortisetosa (Diptera: Hippoboscidae)

Simple Summary

In insects, host searching usually involves different kinds of stimuli, both visual and chemical, that may act in combination. External cues are perceived through specific sensory organs (sensilla), mainly present on the antennae. Understanding how ectoparasites belonging to the Hippoboscidae locate their hosts is crucial, since these flies infest animals and can attack humans, with veterinary and medical implications. The aim of this research was to study the antennae of four hippoboscid species, Lipoptena cervi (Linnaeus, 1758), Lipoptena fortisetosa Maa, 1965, Hippobosca equina Linnaeus, 1758, and Pseudolynchia canariensis (Macquart, 1840), investigating the morphology and the sensory structures present on these appendages. A typical conformation of the antennae with the envelopment of the third segment (flagellum) inside the first two have been observed. Moreover, two types of sensilla have been detected and their role in the perception of host odours and CO₂ have been hypothesized. Other antennal structures seem to be involved in the detection of temperature and humidity variations. Our findings confirm that these hippoboscids use chemoreception for host location, giving insights into this complex process in this poorly investigated group.

Abstract

Lipoptena cervi (Linnaeus), Lipoptena fortisetosa Maa, Hippobosca equina Linnaeus, and Pseudolynchia canariensis (Macquart) are hematophagous ectoparasites that infest different animal species and occasionally bite humans. Hosts are located by a complex process involving different kinds of stimuli perceived mainly by specific sensory structures on the antennae, which are the essential olfactory organs. General antennal morphology, together with distribution and ultrastructure of sensilla, have been studied in detail with scanning and transmission electron microscopy approaches. Observations have revealed some common features among the four studied hippoboscids: (a) typical concealment of the flagellum inside the other two segments; (b) characteristic trabecular surface of the flagellum; (c) peculiar external microtrichia; (d) presence on the flagellum of basiconic sensilla and grooved peg coeloconic sensilla; (e) unarticulated arista. The ultrastructure of L. fortisetosa revealed that microtrichia and the flagellar reticulated cuticle are not innervated. Different roles have been hypothesized for the described antennal structures. Microtrichia and the reticulated cuticle could convey volatile compounds towards the flagellar sensory area. Peculiar sensory neurons characterize the unarticulated arista which could be able to detect temperature variations. Coeloconic sensilla could be involved in thermoreception, hygroreception, and carbon dioxide reception at long distances, while the poorly porous basiconic sensilla could play a role in the host odour perception at medium–short distances.

Detection of Candidatus Bartonella odocoilei n. sp. in Lipoptena mazamae associated with white-tailed deer in Campeche, Mexico

The deer ked Lipoptena mazamae (Diptera: Hippoboscidae) (Róndani), is a blood-feeding obligate ectoparasite of several species of deer and brocket. However, at present little information is available about its role as a vector of hemoparasites. Nonetheless, it is considered a competent vector for the transmission of Bartonella species. The aim of this study was performing the morphological and molecular identification of ked flies and to carry out the detection of Bartonella. We collected specimens from Chiná, Campeche, Mexico associated with white-tailed deer. Using polymerase chain reaction (PCR), of COI, gltA and rpoB genes, we were able to obtain the first barcode for L. mazamae from Mexico and identified a new species of Bartonella which was found with a prevalence of 73%. The data obtained in this study confirmed the presence of L. mazamae associated with white-tailed deer and its possible role as vector of Candidatus Bartonella odocoilei n. sp. in Mexico and we considered that it may also be present in white-tailed deer populations in the U.S.A. Additional investigations into Bartonella species associated with deer ked could provide further insight into their pathogenicity and its role as a zoonotic agent.

Distribution of Deer Keds (Diptera: Hippoboscidae) in Free-Living Cervids of the Tuscan-Emilian Apennines, Central Italy, and Establishment of the Allochthonous Ectoparasite Lipoptena fortisetosa

Simple Summary

In recent years, the increased presence of wildlife in habitats close to urban settlements has raised concerns about the risk of pathogen transmission from wild animals to humans due to the spread of different parasites. For this reason, a survey aimed at describing the dispersal and parasitism level of two cervid ectoparasites was carried out in the northern Apennines, in central Italy. The presence of two hippoboscids, the autochthonous Lipoptena cervi and allochthonous L. fortisetosa, native to Eastern Asia and recently recorded in Italy, were assessed on their main host species (red deer, fallow deer, and roe deer), considering host sex and age. The alien species L. fortisetosa was found to be widespread in the study area, most likely competing with L. cervi. Moreover, red deer seemed to be the favored host of both flies, with differences in sex and age class preferences. This study demonstrated the importance of regularly monitoring the populations of these parasites, especially the invasive species, due to the risks to human health, as these insects are potential vectors of pathogens.

Abstract

Lipoptena fortisetosa and L. cervi are hematophagous ectoparasites belonging to the Hippoboscidae family and preferentially living on cervids. In recent years, they have received specific attention due to the great increase in the abundance of their host species, and to their medical and veterinary importance as possible vectors of pathogens harmful to humans and animals. The aim of this study was to investigate the parasitism level of both of these flies on their main hosts in Italy, which are red deer, fallow deer, and roe deer, and to highlight a possible preference for a species, sex, or age class among the hosts. Deer keds were collected by examining 326 cervids hunted in the Tuscan-Emilian Apennines. Outcomes showed that L. fortisetosa has greatly spread throughout the study area, where it competes with the autochthonous L. cervi. Moreover, red deer was the favored host species of both ectoparasites, while different preferences for host sex and age classes were observed in the two hippoboscids. The regular monitoring of deer ked populations, especially the allochthonous L. fortisetosa, which is continuously spreading in Europe, is recommended to expand the knowledge on these parasitic species that are potentially dangerous to public health.