Chelemys macronyx as host of Ixodes sigelos (Acari: Ixodidae) and additional records for ixodid ticks on sigmodontine rodents in Patagonia, Argentina

MARTIN, G. M.; MASTROPAOLO, M.; NAVA, S.

Jornada; XXIV Jornadas Argentinas de Mastozoología; 2011

Sigmodontine rodents are important hosts for ticks of the genus Ixodes in the Neotropical region. Among this group, Ixodes sigelos is unique in having all its live stages feeding mainly on sigmodontines. Little is known about the biology and ecology of this South American parasite, as well as other ticks from Patagonia. New findings of I. sigelos and other ticks are reported in this work from rodents trapped at different sites near the locality of Cholila (42º31’S, 71º27’W), northwestern Chubut Province (Argentina). Captures were made using Sherman and snap traps from October 2003-October 2004, with a total of 12790 trap/nights, The host-parasite associations recorded are as follow: Oligoryzomys longicaudatus (n:3): 1 larva of Amblyomma tigrinum, 1 female of I. sigelos, 2 nymphs of I. sigelos; Reithrodon auritus (n:1): 1 female of I. sigelos; Loxodontomys micrupus (n:1): 1 nymph of I. sigelos; Chelemys macronyx (n:1): 7 larvae of I. sigelos. All specimens are deposited at the tick collection of the Universidad Nacional del Litoral. Ixodes sigelos has been reported previously on O. longicaudatus, R. auritus and L. micrupus but not on C. macronyx. All stages of this tick were collected at the same locality and dates, providing more evidence that I. sigelos can complete its life cycle on sigmodontines. Also, these rodents are common hosts for larvae of A. tigrinum. The finding of a larva of A. tigrinum on O. longicaudatus represents the first record of this host-tick association, and it is the southernmost record for immature stages of this tick species.