title: An unexpected advantage of insectivorism: insect moulting hormones ingested by song birds affect their ticks.
abstract: Ecdysteroids are important hormones that regulate moulting in arthropods. Three-host ixodid ticks normally moult to the next stage after finishing their blood meal, in the off-host environment. Presumably, three-host ticks that feed on the blood of insectivorous vertebrate hosts can be exposed to high levels of exogenous ecdysteroids causing them to initiate apolysis (the first step of moulting) on the vertebrate host. The aim of the present study was to investigate whether ticks undergo apolysis on insectivorous song birds, and if this phenomenon is associated with the seasonal variation in the availability of moths and with the presence of naturally acquired ecdysteroids in avian blood. During a triannual survey, 3330 hard tick larvae and nymphs were collected from 1164 insectivorous song birds of 46 species. A noteworthy proportion of ticks, 20.5%, showed apolysis. The occurrence of apolytic ticks on birds was correlated with the known seasonality of lepidopteran caterpillars. In addition, 18 blood samples of tick-infested birds were analysed with liquid chromatography - tandem mass spectrometry. Eight samples contained ecdysteroids or their derivatives, frequently in high concentrations, and the presence of these was associated with tick apolysis. In conclusion, naturally acquired ecdysteroids may reach high levels in the blood of insectivorous passerine birds, and will affect ticks (feeding on such blood) by shortening their parasitism.
authors.affiliation: Department of Parasitology and Zoology, Faculty of Veterinary Science, Szent István University, 1078 Budapest, Hungary.
authors.forename: Sándor
authors.initials: S
authors.lastname: Hornok
authors.affiliation: Department of Evolutionary Zoology and Human Biology, University of Debrecen, 4032 Debrecen, Hungary.|Ócsa Bird Ringing Station, 2364 Ócsa, Hungary.
authors.forename: Dávid
authors.initials: D
authors.lastname: Kováts
authors.affiliation: Department of Parasitology and Zoology, Faculty of Veterinary Science, Szent István University, 1078 Budapest, Hungary.
authors.forename: Barbara
authors.initials: B
authors.lastname: Flaisz
authors.affiliation: Ócsa Bird Ringing Station, 2364 Ócsa, Hungary.|Department of Anatomy, Cell- and Developmental Biology, Eötvös Loránt University, 1117 Budapest, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Csörgő
authors.affiliation: Compound Profiling Laboratory, Gedeon Richter Plc., 1103 Budapest, Hungary.
authors.forename: Árpád
authors.initials: Á
authors.lastname: Könczöl
authors.affiliation: Compound Profiling Laboratory, Gedeon Richter Plc., 1103 Budapest, Hungary.
authors.forename: György Tibor
authors.initials: GT
authors.lastname: Balogh
authors.affiliation: Institute of Pharmacognosy, University of Szeged, 6720 Szeged, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Csorba
authors.affiliation: Institute of Pharmacognosy, University of Szeged, 6720 Szeged, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Hunyadi
mesh_terms: D000818:Animals; D026461:Ecdysteroids / Q000097:blood* / Q000737:chemistry; D007915:Lepidoptera / Q000469:parasitology; D018978:Molting; D012621:Seasons; D020308:Songbirds / Q000097:blood / Q000469:parasitology*; D013987:Ticks / Q000254:growth & development* / Q000469:parasitology
chemical_list: D026461:Ecdysteroids