Four new species of chigger mites (Acari: Trombiculidae) of the genus Eutrombicula from Chile

A.A. Stekolnikov and D. González-Acuña

International Journal of Acarology, 36 (4): 313-325 (2010).

S U M M A R Y

Four new species of chigger mites, Eutrombicula chillanensis n. sp., Eutrombicula araucanensis n. sp., Eutrombicula liolaemi n. sp., and Eutrombicula paula n. sp., are described from three species of South American ground lizards of the genus Liolaemus Wiegmann, 1834 collected in Chile.

Using the key to Venezuelan species of Eutrombicula (Brennan and Reed, 1974) Eutrombicula chillanensis n. sp. keyed as Eutrombicula jenkinsi Brennan et Reed, 1974 from the group belkini, but differs from it in having 10—11 (versus 8) setae in first row of D, fV = (6—7)-2-2-2 versus 6-2-4-4-2, wider scutum (AW= 95—103 and PW = 107—117 versus 75 and 90), much shorter AM (29—40 versus 65; PL > AL > AM versus AM > PL > AL), shorter PL and dorsal idiosomal setae (PL = 45—54, H = 45—54, D = 32—52 versus 63, 66, and 53—62), shorter sensilla (S = 58—60 versus 80), and much longer legs (Ip = 1001—1105 versus 824).

Eutrombicula araucanensis n. sp. is close to E. alfreddugesi and differs from it in having a wider scutum (AW = 83—92 and PW = 95—104 versus 73—78 and 86—91), lesser PSB (24—28 versus 30—33), longer PL (45—54 versus 34—39) and H (44—53 versus 35—41), longer legs (Ip = 977—1039 versus 815—896, TaIII = 81—92 versus 70—77), larger m-t (0.286—0.388 versus 0.256—0.275), and shorter tarsala I (14—15 versus 17—18).

Eutrombicula liolaemi n. sp. keyed as Eutrombicula nadchatrami Brennan et Reed, 1974 using the key to Venezuelan species of Eutrombicula (Brennan and Reed, 1974), and differs from it in having much shorter scutal and idiosomal setae (AM = 22—25, AL = 20—27, PL = 32—38, H = 32—37, and D = 25—36 versus 53, 40, 52, 55, and 43—52), PL > AL = AM versus AM ≥ PL > AL, fewer ventral idiosomal setae (fV = 6-2-2 versus 6-2-2-2-2), and somewhat longer legs (Ip = 796—839 versus 730).

Using the key to Venezuelan Eutrombicula (Brennan and Reed, 1974) Eutrombicula paula n. sp. keys as Eutrombicula venezuelensis Brennan et Reed, 1974 from the group belkini. But the new species clearly differs from E. venezuelensis in having branched palpal genual seta versus nude, much smaller number of idiosomal setae (fD = 2H-6-6-2-4 versus 2H-10-8-6-6-2), much lower values for all measurements, and also in other characters.