|New data on prevalence of Trichodectes melis (Phthiraptera, Trichodectidae) in European badger Meles meles (Carnivora, Mustelidae)
Paulina Kozina, Aleksandra Gólcz, Joanna N. Izdebska
Department of Invertebrate Zoology and Parasitology, Faculty of Biology, University of Gdańsk, 59 Wita Stwosza Street, 80-308 Gdańsk, Poland
Corresponding author: Paulina Kozina, E-mail: email@example.com.
Trichodectes melis is a specific ectoparasite of European badger Meles meles. Distribution of this chewing louse is little known, although presumably it coincides in range of the typical host; in Poland it has been found in few stands in the western part of Poland. At present it has been noted in the area of the Białowieża Primeval Forest, where 81 specimens of T. melis were collected from two female European badgers – including 48 females, 7 males and 26 nymph forms, located mainly in fur of the head area. No symptoms of infestation were observed.
Key words: Trichodectes melis, Ischnocera, chewing lice, Meles meles, European badger, Białowieża Primeval Forest.
The louse suborder Ischnocera (Phthiraptera) are highly specialized keratophagic parasites mainly of birds and some mammals, living in their fur or feathers. As a result of long-term evolution of the parasite-host system, they developed advanced adaptations conditioning generation of host, topical or topographic specificity [1,2].
Trichodectes melis (Fabricius, 1805) parasitizes fur of European badger Meles meles (Linneaus, 1758), the biggest predatory representative of Mustelidae family in Poland. The geographical range of European badger includes whole Europe (apart from Northern Scandinavia) and a large part of Asia; in Poland it inhabits the whole country area, while its number is low [3,4]. The range of T. melis presumably coincides in the range of occurrence of its hosts (different badger subspecies), however, it was only occasionally observed e.g. in Spain , the United Kingdom [6, 7, 8], Hungary . The louse has been a species very rarely noted in Poland , where its stands have been found mainly in the western part of the country – Łeba, Międzyzdroje, Suchy Las, Zielonka near Poznań , Lower Silesia region , Łódź . Nevertheless, in many regions of Poland, the occurrence of T. melis is not known.
Most researches concerning badgers, including their parasitic fauna, come from areas more or less transformed by a human, and there is lack data on badgers from well-preserved primeval forest ecosystems. This gap is filled by researches on ecology and social behavior of the badger of the area of the Białowieża Primeval Forest among other carnivorous mammals of the region, which provide much interesting data [13, 14] also on its internal parasites [15, 16]. So far there has been no data on external badger parasites of the region.
Material and methods
Material for the research was obtained from two dead females of European badger found on a road in the area of Białowieża (the Białowieża Primeval Forest, the Północnopodlaska lowland, Poland). The first one was found on 19.03.2013, and the other one – on 21.08.2013 (the material was collected in September 2013).
The badgers were preserved by freezing, and after defrosting they were examined for presence of fur and skin surface parasites . The specimens of T. melis were preserved in 70% ethanol, and then specimens of lice were examined with a stereo microscope, measured (measurements in micrometers), and permanent preparations with polyvinyl-lactophenol were made when needed. The final stage was photo and graphic documentation.
Results and discussion:
Altogether 81 specimens of Trichodectes melis were found in fur of the two badgers: 48 females (Fig. 1), 7 males (Fig. 2) and 26 nymph forms. Comparison of biometric data showed that the examined specimens do not differ significantly from measurements given by other authors in terms of metric features (Table 1). The ratio of males to females in louse xenopopulations was 1:7, while of adult specimens to juvenile stages – 2:1.
In the female badger of March, 20 louse specimens were found, including 11 females (Fig. 3), 3 males (Fig. 4) and 6 nymph forms, while in the other female badger, received in August, 61 lice were noted, including 37 females, 4 males and 20 nymphs. Therefore the sex ratio and the ratio of imagines to juvenile stages in infrapopulations amounted to ca. 1:4 and 2:1 for the sample of March, and 1:9 and 2:1 for the sample of August, respectively.
The lice of the examined badgers exhibited topographic specificity. Most specimens (56% of the sample) were located on the head, in the ear and neck area. There is little data on topography (distribution in different body areas) and topical preferences (i.e. related to microhabitat) of these lice, which, in case of parasitic arthropods, condition e.g. mechanisms of their transmission . According to earlier papers, T. melis was observed on the whole body of its host . However, data on location and topographic preferences of ectoparasites are crucial also in the context of their potential pathogenic importance. Concentration of lice in a restricted area may more easily contribute to development of the population (which may result in parasitosis) than dispersion of the same number of individuals on various body areas. In the present research, in spite of evident topographic preferences of lice, no pathogenic changes were observed on skin surface or in fur. Presumably the determined number and specimen concentration were not troublesome to the host yet.
Unfortunately, there is little data enabling comparison of both morphological features and different aspects of biology, ecology or parasitology of lice of badgers from different regions and environments. The existing few reports as a rule show only records of T. melis in the host, or the number of observed specimens, and more detailed information (including morphometric characterization) has been provided very rarely.
In case of Trichodectidae, most gathered data on the subject concerned species parasitizing farm mammals (domestic or game), or other wild ungulates. In the literature from Poland, one can find detailed data on the subject of species parasitizing roe deer, fallow deer [20, 21, 22, 23], red deer [24, 21, 25, 26] or European bison [27, 28, 29], while predatory mammals only occasionally have been investigated for presence of lice; e.g. in Poland only two otters Lutra lutra were examined in the context of parasitic arthropods, and in one of them specific louse species Lutridia exilis (Nitzsch, 1861) was found [30, 31]. In total, so far 8 louse species have been found in Poland among 84 louse species described from predators [1, 31]. However, they were reported only in few papers, and the body of knowledge concerning them is fragmentary because single reports do not allow to analyze basic features of the parasite-host system related to their frequency of occurrence in host populations and pathogenic importance.
Aknowledgments. I would like to thank the employees of the Mammal Research Institute of the Polish Academy of Science, Białowieża, and especially to doctor Marta Kołodziej – Sobocińska for making the badgers available for the study.