LARVAE OF TROMBICULID MITES ( ACARINA : TROMBICULIDAE ) IN WILD BIRDS IN SLOVAK AND POLISH CARPATHIANS

Literák I . , M. Honza, B. Pinowska, A. Haman: Larvae of Trombiculid Mites (Acarina: Trombiculidae) in Wild Birds in the Slovak and Polish Carpathians. Acta Vet. Brno 2001, 70: 479-483. The larvae of trombiculid mites were surveyed in wild birds at four localities in Slovakia and one locality in Poland (all localities are situated in the Carpathian Mountains) from 1999 to 2000. The total of 1354 birds of 59 species was examined between July and September. The trombiculid mites were found in 169 (12 %) birds. The highest prevalences (37 % and 18 %) were detected at two forest localities in the Veoká Fatra Mts., the lowest prevalence (2 %) in the High Tatras above the tree line. Prevalences of more than 20 % were found in Turdus philomelos (50 %, 5 positive, 10 examined), Prunella modularis (41 %, 48/116), Troglodytes troglodytes (39 %, 11/28), Emberiza citrinella (29 %, 4/14), Turdus torquatus (29 %, 2/7) and Erithacus rubecula (26 %, 64/244). Larvae of the trombiculid mites belong to common parasites in birds in the Carpathians in late summer, especially in birds which are feeding on the ground. Mite larvae were determined as Neotrombicula vernalis (Wil lmann, 1942) in Erithacus rubecula (Krempna, Beskid Niski Mts., Poland) and Prunella modularis (Blatnica, Veoká Fatra Mts., Slovakia). Passerines, parasites, Europe, skin, mountains, Trombiculidae At various localities in Slovakia (Blatnica, Ruské, Necpaly, Tatranská Javorina) and Poland (Krempna) wild birds were examined for cutaneous trematode Collyriclum faba during summer periods from 1996 to 2000. The foci of this trematode were recently recorded in Slovakia (Li terák and Sitko 1997; Li terák and Honza 2000). Cutaneous trombiculid larvae were found in some examined birds in close proximity of the cloaca. Because there is relatively little data about trombiculid mites in wild birds in Central Europe (Daniel 1961; Hait l inger 1987), the aim of our work was to document and compare the prevalences of their larvae in individual species of wild birds in study areas. Materials and Methods Birds were captured in mist-nets and visually examined for cutaneous cysts of Collyriclum faba. Skin was checked on the legs, ventral part of the body, especially between the sternum and cloaca, below the wings, around the preen gland, and on the whole head. Trombiculid larvae were recorded and their occurrence was retrospectively evaluated. Only parasites of two birds were collected into 70% ethanol and determined in the laboratory. Si te descr ipt ions Blatnica (Martin District) 48.56 N 18.56 E, 940 m above sea level The trapping site lies in the Veterná Valley of the Veoká Fatra Mts. near a stream lined mainly with stands of beech Fagus sylvatica and spruce Picea abies. Birds were trapped between 2 and 8 August 1999. Ruské (Snina District) 49.07 N 22.21 E, 600 m above sea level An area abandoned by its former inhabitants in the vicinity of the source of the Cirocha River, Bukovské Hills. Birds were trapped in successive tree growths near the former village of Ruské. At trapping sites, areas with ACTA VET. BRNO 2001, 70: 479–483 Address for correspondence: Doc. MVDr. Ivan Literák, CSc. Department of Biology and Wildlife Diseases Faculty of Veterinary Hygiene and Ecology University of Veterinary and Pharmaceutical Sciences Palackého 1-3, 612 42 Brno, Czech Republic Phone: + 420 5 41562525 Fax: + 420 5 49243020 E-mail: literaki@vfu.cz http://www.vfu.cz/acta-vet/actavet.htm deciduous trees of different age with a predominance of beech alternated with meadows. The birds were examined between 11 and 25 September 1999. Necpaly (Martin District) 48.59 N 18.58 E, 760 m above sea level The trapping site lies near a stream in the Necpalská Valley in the Veoká Fatra Mts. The most numerous around the site were beech and spruce trees. Birds were examined here from 25 July to 6 August 2000. Tatranská Javorina (KeÏmarok District) 49.16 N 20.09 E, 1450 m above sea level The trapping site lies in the Javorová Valley in the High Tatras just above the tree line. Birds were trapped in dwarf mountain pines Pinus mugo, and along a borderline between the dwarf pines and a mountain meadow. Birds were examined between 8 and 19 August 2000. Krempna (Jaslo District) 49.30 N 21.29 E, 400 m above sea level The trapping site was on the borderline between farms and large forests in the Beskid Niski Mts. The nets were situated near a stream along the edge of a deciduous forest, and in a shrub growth between farm buildings. Birds were examined between 21 and 26 August 2000.

At various localities in Slovakia (Blatnica, Ruské, Necpaly, Tatranská Javorina) and Poland (Krempna) wild birds were examined for cutaneous trematode Collyriclum faba during summer periods from 1996 to 2000.The foci of this trematode were recently recorded in Slovakia (Literák and Sitko 1997;Literák and Honza 2000).Cutaneous trombiculid larvae were found in some examined birds in close proximity of the cloaca.
Because there is relatively little data about trombiculid mites in wild birds in Central Europe (Daniel 1961;Haitlinger 1987), the aim of our work was to document and compare the prevalences of their larvae in individual species of wild birds in study areas.

Materials and Methods
Birds were captured in mist-nets and visually examined for cutaneous cysts of Collyriclum faba.Skin was checked on the legs, ventral part of the body, especially between the sternum and cloaca, below the wings, around the preen gland, and on the whole head.Trombiculid larvae were recorded and their occurrence was retrospectively evaluated.Only parasites of two birds were collected into 70% ethanol and determined in the laboratory.

Site descriptions
Blatnica (Martin District) -48.56 N 18.56 E, 940 m above sea level The trapping site lies in the Veterná Valley of the Veºká Fatra Mts.near a stream lined mainly with stands of beech Fagus sylvatica and spruce Picea abies.Birds were trapped between 2 and 8 August 1999.Ruské (Snina District) -49.07 N 22.21 E, 600 m above sea level An area abandoned by its former inhabitants in the vicinity of the source of the Cirocha River, Bukovské Hills.Birds were trapped in successive tree growths near the former village of Ruské.At trapping sites, areas with deciduous trees of different age with a predominance of beech alternated with meadows.The birds were examined between 11 and 25 September 1999.Necpaly (Martin District) -48.59 N 18.58 E, 760 m above sea level The trapping site lies near a stream in the Necpalská Valley in the Veºká Fatra Mts.The most numerous around the site were beech and spruce trees.Birds were examined here from 25 July to 6 August 2000.Tatranská Javorina (KeÏmarok District) -49.16 N 20.09E, 1450 m above sea level The trapping site lies in the Javorová Valley in the High Tatras just above the tree line.Birds were trapped in dwarf mountain pines Pinus mugo, and along a borderline between the dwarf pines and a mountain meadow.Birds were examined between 8 and 19 August 2000.Krempna (Jaslo District) -49.30N 21.29 E, 400 m above sea level The trapping site was on the borderline between farms and large forests in the Beskid Niski Mts.The nets were situated near a stream along the edge of a deciduous forest, and in a shrub growth between farm buildings.Birds were examined between 21 and 26 August 2000.

Intensity of infection and prevalence of trombiculid mite larvae in wild birds
The intensity of parasitic infection varied among individual birds -from individual mites to mite groups not countable by eye.In the case of more mites, clearly demarcated orange colonies with the diameter up to 1 mm were seen.In some cases, there were more mites around the cloaca or created a ring-shaped circle round the cloaca (Plate VI, Fig. 2).
The parasites were found in all of the five Carpathian localities (Table 1).Prevalences of neotrombiculid larvae reached 37 % in Blatnica in August 1999, 10 % in Ruské in September 1999, 18 % in Necpaly between July and August 2000, 2 % in Tatranská Javorina in August 2000, and 14 % in Krempna in August 2000.The total prevalence was 12 %.

Discussion
The mite Neotrombicula vernalis collected from two birds (Prunella modularis in Slovakia and Erithacus rubecula in Poland) was unambiguously determined.Because findings in other birds were practically identical concerning colour and size of parasites as well as the place in immediate proximity of the cloaca, these mites were determined as trombiculid larvae.
Trombiculid larvae that infest mammals and birds can usually cause skin pruritus in affected individuals due to saliva excretion of larvae.Lytic enzymes in saliva cause the formation of tubes penetrating dermis (histiosiphon or stylostom) so that the larvae can suck macerated tissue of the host (Coignoul 1976).Heavily parasitized birds become droopy, refuse to eat, and may die from starvation and exhaustion (Philips 1998)   Nt -Not tested, 1 -Positive, 2 -Tested, 3 -Prevalence (%), so heavy, that a negative influence on the health status was probable in affected individuals.
According to our results, the infestation of wild birds by trombiculid larvae is common in Slovak Carpathians from July to September.There is not much work on this topic in Central Europe.Only Daniel (1961) examined 16 species of birds in the area of eastern Slovakia (Ondava Higlands).He found in four bird species four species of trombiculid larvae: Neotrombicula autumnalis (Shaw 1792) s. l. in Turdus ericetorum and Phoenicurus ochruros, Neotrombicula talmiensis (Schluger, 1955) in Sylvia communis, Leptotrombidium europaeum (Daniel et Brelih, 1959) and Ascoschoengastia latyshevi (Schluger, 1955) in Parus major.
N. autumnalis belongs to the commonly occurring mites in Slovakia (Vater, 1982); however, their distribution was studied especially in small ground mammals (recently, e.g.Kalúz et al., 1996).From the species group of Neotrombicula autumnalis, the species Neotrombicula inopinata (Oudemans, 1909), N. vernalis (Willmann 1942) and N. earis (Kepka 1964) were found in small mammals in Vihorlat Mts., Malé Karpaty Mts. and in the Záhorská Lowlands (Kováãik 1983(Kováãik , 1984(Kováãik , 1985)).The species N. vernalis and N. earis are considered to be the steppe species in the area of the Malé Karpaty Mts., inhabiting forest-steppe and steppe habitats.Our finding of N. vernalis in Prunella modularis in the higher part of Veºká Fatra Mts.indicates that the ecological valence of this species is larger than predicted.
In Poland, N. autumnalis s.l.belongs to the commonly occurring mites.However, in birds it was described for the first time in Sitta europaea in September 1982 (Haitlinger 1987).
It is obvious that affected wild birds in the Slovak and Polish Carpathians often foraged on the ground.A remarkably high prevalence of mite larvae was found in some Slovak localities, especially in Prunella modularis.We think that different prevalences in individual species of wild birds depend on various length of individual exposure in the environment with neotrombiculid larvae occurrence.All six species with prevalence higher than 20 % belong to the ground feeding or near-ground feeding species.Individuals from other groups feed on the ground only occasionally and that apparently is the reason for their lower parasitic prevalence.
In the forests of the Carpathians in the Veºká Fatra Mts., Bukovské Hills and Beskid Niski Mts., the mite larvae prevalence was 10-37%.A remarkably lower 2% prevalence was noticed in wild birds in the High Tatras.The growth of dwarf pines above the tree line in Javorová Valley, the site of bird examination in the High Tatras is probably less convenient for larvae of trombiculid mites than the Carpathian forests, nevertheless the occurrence of larvae of trombiculid mites is possible even in this environment at 1450 m above sea level.
In affected birds, larvae of trombiculid mites were exclusively in close proximity to the cloaca.Mites N. autumnalis were observed in Turdus merula in the Netherlands in the same body area (B r onsvijk 1977).

Fig. 2 .
Fig. 2. Prunella modularis with larvae of Neotrombicula vernalis around its cloaca.(Photoby Marcel Honza) . Intensity of the larvae of neotrombiculid mite infection was in some cases, especially in Prunella modularis