Biology Reference
In-Depth Information
3
Geographic Distribution and
Ecologic Preference
Haemaphysaline ticks are found in different ecozones such as Indomalaya, Palearctic,
and Southeast Asian regions, indicating their ecologic adaptations.
68,85,136
Of 42
species of Indian Haemaphysalis ticks, 16 species are confined to southern peninsular
India and the remaining are distributed in northeastern and Himalayan regions. It is
interesting to note that some of the species belonging to the latter regions such as
H. sulcata, H. doenitzi, H. campanulata,andH. bispinosa extend their distribution to
Palearctic and Australian ecozones. Certain species are restricted to only certain states,
such as H. kyasanurensis and H. megalaimae in Karnataka state, H. sambar in Kerala
state, and H. sundrai in Uttarakhand state, whereas species like H. bispinosa are
widely distributed, occurring practically in almost all Indian states. Ecologic prefer-
ences of different subgenera of Haemaphysalis ticks are varied. Most of the structur-
ally advanced (SA) populations occur below 1,500 m altitude in the Himalayas or
elsewhere. All the species belonging to subgenus Herpetobia and other structurally
primitive (SP) species are confined to sub-tropical or temperate steppes, semi-deserts,
or mountains. These are the species that are supposed to have failed to find
suitable host and remained in isolated location as relics. Species belonging to contem-
porary subgenus Alloceraea are notably absent in humid tropical regions, whereas
many SA haemaphysaline are common in tropical Asian forests where two, three, or
more species can be found infesting a single mammal. The single species belonging to
Alloceraea in India, H. aponommoides,
is confined to Himalayan and southern
Chinese highlands (2,000
4,900 m altitude). In the cold high Himalayas, adults of
H. aponommoides are active through much of the year. The cold season adult activity
pattern is an adaptation to prevent the desiccation during the dry hot summer. The
unique leathery Alloceraea integument probably is an adaptation for water conserva-
tion. The relict type ticks in the subgenus Allophysalis (H. garhwalensis and
H. warburtoni) perhaps avoid competition from other ticks by being in the rocky bio-
topes in the 1,600
2,000 m altitude range of Asian mountains including the
Himalayas.
3.1 Host Preferences
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Most of SA haemaphysalines, both adults and immatures, parasitize domestic and
wild mammals and birds. Generally small mammals are infested by immature
