Diversity and distribution of nematodes associated with wild bees in Turkey

AbstractThe diversity and distribution of nematodes associated with soil-dwelling bees in Turkey were examined. A total of 9456 wild bees were collected and dissected to detect nematodes and 173 female and 22 male bees were positive for an overall association level of 2.1%. Halictus resurgens was the most commonly collected bee found with nematodes with 82 and 19 nematode-infested female and male bees, respectively. Sixty-four of the nematode isolates were recovered from the Black Sea region (32.8%), 59 from Central Anatolia (30.3%), 35 from the Mediterranean (17.9%), 24 from the Aegean (12.3%), six from Eastern Anatolia (3.1%) and seven from Southeast Anatolia (3.6%). In 3.9% of all bees of the family Halictidae (173/4417), nematodes were observed in the Dufour's gland, poison sac, oviduct, bursa copulatrix and abdominal cavity of dissected female bees and from the genital capsule of male bees. Only abdominal glands of 0.6% (21/3279) of female bees from the family Andrenidae were observed with nematodes. Nematodes were isolated from the genital capsule of one male bee from the family Melittidae. The poison sac was the organ where nematodes were most often observed but the highest number of nematodes occurred in the abdominal cavity. Most nematodes were in the dauer juvenile stage making identification difficult. Sequence analysis using LSU D2/D3 domains and a fragment of mitochondrial cytochrome oxidase I (mtCOI) allowed for putative identification of nematode isolates. Two or three species of Bursaphelenchus (B. anatolius, B. debrae, and potentially one or more cryptic species closest in morphology to B. anatolius) were isolated from six different halictid species (two genera; Halictus and Lasioglossum) from different geographical regions in Turkey. An additional four species of diplogastrid were recovered from the abdominal glands of andrenids; a new species of Koerneria from Andrena limata and a separate sister clade to Mononchoides composed of three other possible species from four Andrena species. An additional unknown species in the order Tylenchida (near Allantonematinae) was recovered from three species of Lasioglossum. No molecular data were obtained from three mermithid juveniles from two Andrena and one Halictus species because samples were lost in transit. The associations of most nematode isolates with bees of the families Halictidae and Andrenidae were hypothesised to be phoretic, whereas the tylenchid and mermithids were parasites.