Variability
in Leptotrombidium
europaeum and two new related chigger mite species
(Acari: Trombiculidae) from Caucasus
A.A.
Stekolnikov
Parazitologiya, 38(5):
388-405 (2004) (In Russian, English summary).
S U M M A R Y
Two new
chigger mite species closely related to Leptotrombidium
europaeum (Daniel et Brelih, 1959) are described from small
mammals collected in Caucasus and Transcaucasia. L. alanicum
sp.n. differs from L. europaeum in having
shorter legs (TaIII = 61—81, Ip = 734—927 versus 72—90, and 855—1017),
shorter scutal and idiosomal setae (Dmin =
30—45, Dmax = 48—67, H = 59, PL = 58 versus
40—52, 54—69, 64, 63), slightly smaller scutum (AP = 25, SD = 47, PW =
89 versus 28, 50, 91), and more numerous idiosomal setae (87 versus
81). L. montanum sp. n. differs
from L. europaeum in having more numerous idiosomal
setae (102 versus 81), longer scutal and idiosomal setae (AM = 61, AL =
44, H = 68, Dmax = 66 versus 56, 41, 64, 62),
thicker legs (TaW = 19 versus 18), and broader scutum (PW = 95 versus
91). Exact identification of both new species is possible only using
classification functions constructed by means of discriminant analysis.
These three Leptotrombidium
species expose sympatric distribution in Daghestan (Eastern Caucasus). L.
alanicum and L. montanum also occurred
together in Krasnodar Territory (Western Caucasus). Each of these
species includes a number of local geographical forms precisely
distinguished from each other. Morphometric differences between L.
alanicum and L. montanum agree with
eco-geographic rules being previously found in chigger mites from other
genera. However, differences between local forms of these species show
other tendencies, directed controversially in part. Therefore it is
probable that interspecific differences in this case correspond to the
variability which took place in the process of speciation.
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