Biology Reference
In-Depth Information
1.1 Tick Studies: Historical Background
Ticks, which have been around in much the same form for approximately 200 mil-
lion years, are among the oldest and most successful groups of arthropods.
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They
were described as pests by the ancient Greeks and ever since have been treated in
literature mostly with revulsion. These primitive, obligate, bloodsucking parasites
prey on every class of vertebrate in all parts of the world. Ticks were the first
arthropods to be clearly established as vectors of infectious disease, owing to the
discovery in 1893 by Smith and Kilbourne of the role of Boophilus annulatus as
the vector of Babesia bigemina, the protozoal cause of Texas cattle fever.
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A
decade or so after this discovery, mosquitoes were established as the vectors for
malaria, yellow fever, and filariasis. In 1903, ticks were first proved as vectors of
human disease, when J.E. Dutton, working in the Congo, discovered the principal
cause of endemic relapsing fever (named Babesia duttonii) and its argasid (soft-
tick) vector, Ornithodoros moubata.
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A perusal of literature reveals that the history of our knowledge of the Indian
ticks dates from the time of Linnaeus who described Acarus elephantinus in 1758
and Acarus indus in 1767 from India.
104,126,127
Both these species were invalid
according to Neumann (1911), who published a monograph on ticks, “Ixodidae”
wherein he described a few tick species belonging to seven genera, Haemaphysalis,
Ixodes, Amblyomma, Aponomma, Dermacentor, Hyalomma, and Rhipicephalus
from India. In an earlier series of papers published between 1897 and 1910, he had
described a number of new species belonging to the above genera. In 1907,
Warburton published a short account of certain Indian species. In 1910 Warburton
published a report on the ticks belonging to the Indian Museum wherein he added a
number of additional tick species belonging to the above-mentioned genera. Nuttall
and Warburton along with Robinson and Cooper published Part II and Part III of a
comprehensive work entitled “Ticks: A Monograph of Ixodidae” in 1911 and 1915.
This was followed by Part IV in 1926 by Robinson.
The next major work in Indian tick research was by Sharif (1928) who reported
a checklist of 45 species from the collections in the Indian Museum, Calcutta.
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The next checklist was by Sen (1938) who reported 50 species. The discovery of
Kyasanur Forest Disease (KFD) from ticks in March 1957 marked the next mile-
stone in the history of Indian tick studies and stimulated extensive studies on differ-
ent aspects of studies on Indian ticks, which included taxonomy, distribution,
biology and ecology, disease relationships, and control.
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Subsequently the tick
fauna of the KFD, which presented a perplexing array of nomenclature and identifi-
cation problems, involving larvae, nymphs, and adults of 14 Haemaphysalis spe-
cies, were solved by the classic work by Trapido et al. (1964) who prepared a key
for the identification of these ticks. Detailed studies on the ecology of ticks in India
are mostly confined to the ticks of KFD area. Great contributions by the late
Dr. Harry Hoogstraal in the study of Indian ticks especially systematics is worth
mentioning here. He has been instrumental in getting a number of new species
described from India. The extensive field studies on Haemaphysalis spinigera,
