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2. LITERATURE REVJEW
Taxonomic status
Anopheles jeyporiemis was first described by James (1902) from the specimens collected
at Jeypore hill tracts (Type locality). Later, Theobald (1903) also described this species under
the same name from three females and two males obtained from the same locality. Koidzumi
(1924) described the variety d i d i e n s i s of this species based on morphological (palpal)
variations from a number of adults and larval specimens from Lake Candidus, Formosa
(Taiwan). Christophers (1 933) described the differences in both adult and larval characters
between the type form and the var. carkijrl'eenris. Totimanoff (193 1) described a synonym of the
variety camidensis as Anopheles aconltus var. tonhnensis in Tonkin. The variable banding
pattern in paipi in An jeyporienris gave rise to both synonyms, concfidienris and tunkinemis.
Christophers (1933) suggested the presence of one palpal variation in Lndia and the other only in
east of India. However, Macan (1948) and Khin-Maung-Kyi (1971) in Burma and
Rattanarithikul and Harrison (1973) in Thailand observed that both variations plus imamediates
typically occur together.
Menon and George (1950) recognised 4 distinct palpal patterns among 354 An.
je*ensis females collected from Kerala. However, they considered them as gradations in the
variations of the type-form and not as true varieties (like can&diensis) since variation had
proceeded along a common line Erom the type form. Chow (1970) pointed out that these palpal
variations in An. j e p n ' e n s i s exist together over a wider geographical area (India to Hong-Kong)
and obviously the variants can not be considered as subspecies.
Harrison (1980) examined a total of 1215 An. j e p r i e n s i s specimens f?om different
countries viz., Cambodia, China Hong Kong, India (Assam, Orissa-includes type specimens of
An. jeyporiensis in BMNH), Nepal, Taiwan and Thailand of oriental region and concluded that
the palpal variations are continuous through out the region and therefore, the variants need not be
coined with different names. The variety of An. jepon'enns that was originally named as
c d d i e n s i s is nothing more than a form with wide spread variations in palpi that occur with
varying frequency in different parts of the oriental region.
Therefore, in the following chapters, the literature relating to the type form and o t h a
variants of An. jeyporiensis have invariably been treated as that o f A n j e p r i e n s i s .
Characteristic features
The characteristic features of An. jeporienris adult, larva, pupa and egg are desaibed in
detail by Christophm (1933). Later, Hamson (1980) described the presence- of gray or gray-
brown scales on the remigium-R base of wings in female specimens and this new ~ 8 r a c t a wss
helpful in identifying many specimens of A n jeporieRFis. Subsequent to this, no taxonomical
studies were carried out.
Distribution
An. jeyporiensis has been reported only f?om oriental region. The distribution of this
species in different parts of orient is summarised in Table 1. Its distribution extends fiom Indo-
China peninsula in north to Kerala (India) in south and from Taiwan in east to Maharastra (India)
in west (Fig. 1). An. jeyporiensis is reported from all over India except in Jammu and Kashmir,
Himachal Pradesh, Arunachal Pradesh, Mizorarn and Andaman and Nicobar islands (Fig. 2). It is
a very common species in Western Ghats (Karnataka, Keraia and Maharashtra) and east central
India (Bihar, Madhya Pradesh, and Orissa).
Outside India. this species has been recorded in Burma, Bangladesh (on b o d with
Burma), Cambodia, Hong Kong, Laos, Nepal, China, Taiwan, Thailand and Vietnam. Among
these countries, An. jeypor~ensis is more abundant in south China from Yunnan Province to
Fukien and in northern parts of Burma, Laos and Vietnam.
An. jeyporiemis is a hill-mountain species which has been found at altitudes ranging fiom
60 ft in Vietnam (Stage, 1958) to 5000 A in Tonkin (Indo-China) (Toumano& 1932b) above
Mean Sea Level (MSL). Relative abundance of this species was higher at altitudes ranging h m
500 ft to 3000 A above MSL where climate is cool (Stephens and Christophcrs, 1902; Perry,
Table 1 . Distribution of An.jeyporiensis in Oriental region.
Locality Source
1 BANGLADESH (on border with Burma)
2.BURMA Kabaw and Kale valleys Arakan Mandelay Loikaw district
3.CAMBODIA Kompang and Chhnang Snoul
4.CHINA Arnoy Islands (Fukien) Hainan Kulangsu Kwangsi Kwangtung
Kweichow Mubein Yunnan
5.HONG KONG
Andhra Pradesh Visakhapatanam
Assam Boko area (Kammp district) Cachar
Plains of Assam
Macan, 1948 Macan, 1950 Christophers, 1933 Khin-Maung-Kyi, 1971
Harrison and Klein, 1975 Klein, 1977
Feng, 1932; Lee, 1933 Riley, 1932 and Ho Chi, 1938 Lee, 1933 Feng, 1936; Luh et at., 1961 Wu (Liang-Yu). 1935; Lee, 1957; Che Lee, 1960 Yao and Ling, 1937 Luh, eta/., (1961) Gaschen, 1934; Ling et a/. . 1936; Chang, 1940; Robertson, 1940
Jackson, 1935 and 1936, Burke, 1937; Toumanoff. 1934
Senior White and Venkat Rao, 1943
Nandi et a/. , 1 993 and Dutta et a/., 1994 Ramsay, 1929; Strickland, 1929; Ramsay et a/. , 1 936 Clemesha, 1927
Contd.
Locality Source
Bihar Hazaribhagh ranges Basu, 1929; Senior White, 1943 Manbhum district Mitra, 1938 Singhbhum hills Senior White and Narayana, 1940
Goa Borcar et a/. , 1967
Gujarat Baroda
Kamataka Coorg Hassan district Mandya Mysore state North Kanara
Shimoga district
Kerala Kulasekharam Perumpazhuthoor Travancore Wynaad
Madhya Pradesh Satpura hills Udaipur Bastar district
Maharashtra Pune Thane district
Webster, 1929
Young and Baily, 1928 Brooke Worth, 1953; Sitaraman et al., 1961 Rao and Nassiruddin, 1945 Nursing et a/. , 1934 Viswanathan and Rao, 1943 Singh and Jacob, 1944 Rao et a/. , 1952
Mathew, 1939 Mathew, 1939 lyengar, 1934 Home, 191 4; Covell and Harbhagwan, 1939
Stokes, 1913 Roy and Biswas, 1942 Prakash and Husainy, 1974; Kulkami, 1987 and 1990; Husainy, 1991
Viswanathan, 1950 Rao, 1984
Manipur Mortirnber, 1946; Rajput and Singh, 1986
Meghalaya Rajagopal, 1976
Nagaland Misra et a/. , 1993
Contd.
Locality Source
Orissa Chilka lake area
Coastal plains Jeypore hills
Senior White and Adhikari, 1939 and Cove11 and Pritam Singh, 1942 Senior White et a/., 1943 Stephens and Christophers, 1902; Perry. 191 4; Senlor White. 1937 and 1938 Weeks, 1951 ; Gunasekaran et a/., 1989
Punjab Sagandeep et a/. , 1994
Rajastan Puri, 1948
Tamil Nadu Anaimalai Hills Nilgiris
Measham and Chowdhuri, 1934 Chrlstophers and Chand, 191 6
Tripura Misra and Dhar, 1955
Utter Pradesh Doon Valley Himalayan region Nainital Terai
Juhari et a/. , 1 992 Rao et a/. , 1973 Strickland and Chowdhuri, 1933
West Bengal Bengal Dooars Khan, 1929 Da rjeeling Malakar et a/., 1995 Manharpur Christophers 1923 Sub-montane region lyengar, 1927
7.LAOS Luang Prabang and Paklay (Mekong) Monier, 1933 Phong Saly and Tranninh Lefebvre, 1938
8.NEPAL Shreshta. 1966
9.TAIWAN (Formosa) Secrete, 1916; Koidzumt, 1926 and 1 927; Omori, 1 942
Contd.. .
Locality Source
1O.THAILAND Chiang Mai Province Sandhinand, 1951 ; Thurman and Thurman, 1955 Lampang, Mae Hong Son and Phayao Harrison, 1980
11 .VIETNAM Thay Meo Lysenko and Nguien. 1961 ; Thay Nguyen (Tonkin) Stage, 1958; Lysenko et a/., 1961 ; Huong-Hoa and Ninh-Sim Do-Van-Quy et a/. , 1963
1914; Lefebvre, 1938; Jackson, 1951; Brooke worth, 1953; Stage, 1958; Borcar et d., 1967 and
Rajput and Singh, 1986).
Larval habitats
Small streams and seepage water draining from hill sides form the ideal larval habitats
for this species (Perry, 1914; Iyengar, 1926; Feng, 1936; Senior White, 1946; Tournanoff,
1932a and Dev, 1994). In addition, larvae of An. jeyporem~s were collected from pools, ponds.
swamps, tanks and terraced rice fields where water replacement took place (Young and Baily,
1928 and Chang, 1940). Immatures were also found in fallow rice fields (Chow, 1949; Senior
White, 1946 and Dev, 1994), pools in rice stubble after reaping of crop (Jackson, 1935 and
1936) and marshes (Macan, 1948). lmmatures of An. je-ems were found in channels with
marginal vegetation in North Kanara (Rmo, 1945), in riverbed pools in Tamil Nadu (Rahman et
a[., 1975) and in shaded jungle ravines in Madhya Pradesh (Stokes, 1913).
The larval habitats of An. jeyporiensis could be summarised as: clear cool h s h water,
slow moving or nearly stagnant, with thickly grown emergent vegetation which provide partial to
heavy shade. The bionomics of Am jeyporiemis immatures in a given locality vary according to
local environmental conditions and climatological factors.
An jeyporiemis was more abundant during post-monsoon and cold (Novmba to March)
seasons and either disappeared or the abundance r e d u d during the monsoon months (August to
September) in India (Pmy, 1914 and Senior White, 1938; Singh and Jacob, 1944; Young and
Majid, 1929; Kulkami, 1990; Nandi et al., 1993 and Misra ef al., 1993).
Similar seasonal pattern was observed in Hong Kong (Jackson, 1936). The population of
An. jeyporiensis was numerous during pre-monsoon period (April to May) in Arakan region of
Burma (Macan, 1950) and low when the rainfall occurs (June-October). However, in Kabaw and
Kale valleys of Burma, this species was collected in high numbers during rains (Macan, 1948).
Thus, the seasonal abundance of An. jeyporiems is mainly influenced by the quantum of
rainfall that occurs in a particular region. Since An jeyporiensis immaturcs wae found in
habitats with moving water, the continuous flushing of larvae during rains is tbe main
contributory factor in limiting the An jeyporienris population.
Diversity
An jeprienris was recorded to be predominant in Jeypore hills (Perry, 1914) and in
North Kanara (Singh and Jacob, 1944). In Darjeeling (West Bengal) (~alakar el al., 1999,
Cachar district (Assam) (Ramsay, 1929), Udaipw (Roy and Biswas, 1942) and Bastar disbict of
Madhya Pradesh (Husainy, 1991) An je-ems represented less than 0.5% to 9.6% of the total
anophelines collected.
An, jeyporiensis constituted 5.78% of larvae and 6.30% of adults collected at Yunnan
Province, China (Chang, 1940). Also in Thay Meo district of North Vietnam, An. jeyporiensis
represented only 21.4% of the total anophelines collected (Lysenko and Nguien Tien Byy 1961).
More than 80% of the catches from houses in Vietnam constituted both An. mrnlmus and A n
jeyporiensis (Stage, 1958).
Relative abundance o f females
Number of females of any given species is an important parameta with ref= to
transmission of parasitedpathogens. The relative number of A n jeypwrenvs adult. caught
resting indoors was very low, ranging &om 0.01 to 1.06 per man-hour in Bastar disma (h4adhya
Pradesh) (Kulkarni, 1990) and &om 0.02 to 0.14 p a man-how in Nagaland (M~sa et d., 1993).
The number of females landing on human bait was only 0.12 per man per hour in Nagaiand
(Nandi et al., 1993) and 1.9 per man per night in Madhya Pradesh (Kulkami, 1987).
Tolerated abundance (elsewhere noted as tolerated density) of a vector species is defined
as the highest limit of abundance of female mosquitoes up to which the risk of transmission is nil
(Bhntia and Wattal, 1958). In case of A n jeypon'emis the tolerated abundance was estimated to
be 3 per man-hour of indoor resting collections (Singh el al., 1957).
Resting behaviour
An. jeyporienris was commonly regarded as a domestic species resting largely in human
dwellings and cattle sheds (Perry, 1914; Christophers, 1933, Nursing et uf., 1934; Senior White,
1937 and 1938; Che Lee, 1960; Nguyen-Thuong-Hien, 1968, Kulkami, 1990 and Dutta et of.,
1994).
Reports are available to show the preference of An. jeyporensis to cattle sheds for day
time resting (Russell and Jacob, 1942; Covell, 1944; Singh and Jacob, 1944; Senior white et ol.,
1945; Prakash and Husainy, 1974 and Juhari et al., 1992 and Malakar et uf., 1995).
Senior White and Ghosh (1946) reported that in Jeypore hills, the most prefared sites of
An. jeyporiensib in human dwellings were walls and doors (42.5%) followed by thatched roof
(34%). The species was reported to prefer dark corners and hanging clothes for resting in Hong
Kong (Jackson, 195 1). No report on preferential resting sites of An jeporiensis in cattle sheds is
available.
An jeyporiensis was assumed to show exophilic behaviour since it wuld neva been
collected indoors during day time though encountered during night catches in houses in Burma
&iun-Maung-Kyi, 1971). This species was o b w e d to move away &om indoors to outdoors to
complete the second half of the gonotrophic cycle in Jey-pore hills (Senior White el d., 1945).
Resting behaviour of this species in relation to indoors and outdoors was studied only during
cold season in Bastar district, Madhya Pradesh, (Kulkami, 1990). No other reports are available
to assess the degree of exophily in relation to space and time.
Biting periodicity
No definite pattern in biting periodicitylfeeding habits of An. jeypriem~s has been
reported. House Frequenting of An. jeyprlensrs was observed mainly between 04.00 and 06.00
hours in Karnataka (Nursing et al., 1934) whereas in Burma, between 22.00 and 24.00 hours and
between 01.30 and 03.30 hours (Macan, 1950). An. jepriemis entered the human habitations
between 01.00 and 03.00 hours in Vietnam (Nguyen-Thuong-Hien. 1x8). Smoke in the houses
seemed to delay the entry of the mosquitoes.
The biting activity of An jeprrenns was observed throughout night with higher activity
till mid night and influx peaked just after dusk in Bastar district, Madhya Pradesh (India)
Wulkarni, 1987) and in Mubein, Kwangsi province (China) (Luh el al., 1%1). In Taiwan, This
species entered the man baited net trap sporadically without any definite pattern (Omori, 1942).
Thus, the reports on biting periodicity of An j e p n e n n s show considerable variations in
different areas. Th- studies afe not comparable, mainly because of the fact that the local
av~ronment and m n play an important role in determining the pattern of biting activity.
Host selection
Feeding of An. jeyporiensis females on human is well known but the proportion fed on
human and cattle varied considerably. Outside India, An. jeypor~ensis was reported to be highly
anthropophilic. The anthropophilic index of this species varied between 51.2% and 97% in
different parts of Indo-China (Tournanoff et al., 1939; Raynal and Gaschen, 1935; Gaschen and
Raynal, 1937).
In India, the anthropophilic index of this species was reported to be low i.e., 12.5% in
Jeypore hills (Senior White et al., 1945) and 17% in Bastar district, Madhya Pradesh (Husainy,
1991). An anthropophilic index of 52.9% was reported for An. jeprienns in Assam (Ramsay et
al., 1936). However, the number tested was too small (n-17) to wme to a definite conclusion.
The presence or absence of cattle population was reported to influence the feeding habit
of An. jeypwrenns to a certain extent. The anthropophilic index of An. jeyponenris was 76.3% in
Shing Mung Camp (Hongkong), where cattle were absent Whereas, in Woo Li Hop (Hongkong).
where cattle and other domestic animals lived side by side their owners, the anhpophil ic index
was 46%. In Sheung Kwai Chung (Hongkong), where cattle were present, out of 28 samples
tested, none rcaued with human anti-sera (Jackson, 195 1).
Flight range
The flight range of An jeyporierzsis in Hongkong exceeded half a mile (Jackson, 1935).
In mark-release-recapture experiments in Jeypore hills, this species was observed to disperse
over 420 m for oviposition (Senior White el ol., 19452 In the same area, a recent study indicated
a dispersal range of 1700 m (Sadanandane et al., 1993).
Adult longevity and gonotrophic cycle
In mark-release-recapture studies in Jeypore hills, a very high percentage of survival for
over 12 days in cold weather was observed (Senior White er al., 1945). In the same area, the
duration of gonotrophic cycle of An jeyporlensis was 72 hours in cold season (Senior White el
al., 1945). No other report is available on longevity of this species.
Experimental infection
An jepr iens is was found to develop oocyst infections following experimed feedings
in Indo-China (Robin and Toumanoff, 1934). In China, Xu (1986) fed 8 lots of An jcyporiems
on gametocytaemic (P. vrwrr) blood and of these, 4 lots developed gland infections. The gland
infection rates were as high as 1000/o with a mean positive gland index of 3.73. I n f o d o n on
s~sceptibiiity of An jeyporiemis to human plasmodia in India is not available.
Natural infection
Details of natural infections recorded in An. jeporiensis, in different parts of Onental
region are summarid in Table 2. An. jeyporiensis was one of the major vectors of malaria in
south China (Fen& 1932 and 1936; Jackson, 195 1; Tournanoff, 1933 and Robertson, 1940 and
194 1; Zhou, 198 1, Chow, 1992 and Zhu and Huang, 1995), Burma (Macan, 1950) and Lndo-
China (Covell, 1944; Brandling-Bennen el 41.. 1981). Natural infections with both oocyns and
sporozoites were found in these regions. The sporozoite rate recorded in Arakan (Burma-
Bangladesh border) was 1.6%. In Lndo-China. the infection rates ranged from 0.7% in Annarn to
2.25% in Tonkin Whereas in China. the infection rates ranged from 1.9% in Yunnan Province
to 5 9% in Hongkong.
Besides malaria parasites, infections with filarial parasites, Brugra and
Wucherena bancrofn were found in An. jeyporienns in China (Hawking, 1973).
In India, no sporozoite specimen was recorded amongst wild caught females. Oocyst
infections were found in specimens &om Assarn (Ramsay el al., 1936). Orissa (Senior White,
1937 and 1945 and Senior White et al., 1945) Karnataka (Nuning et al., 1934) and Kerala
(Iytngar, 1934). Oocyst rate ranged from 0.04 % in Assam to 3% in Orissa.
The various dissection results showed that An jeyponenns is an important malaria veaor
in countries outside India. However, in India, the role of this species in the transmission of
malaria parasites remains unresolved.
Table 2. Dissection results showing natural infections in An.@yporiensis with malarial parasites.
Locality Number Number positive dissected GuffGland Gut Gland Total % Source
BURMA Arakan-Bangaladesh 01126 0 2 2 1.6 Macan, 1950 Kabaw 8 Kale valleys8una 011 64 0 0 0 0 Macan. 1948
CHINA Amoy islands(Fukien) 30127 1 0 1 3.3 Feng, 1932 Hongkong 28706 1085 616 1701 5.9 Jackson, 1951 Kwangsi 56 2 0 2 3.6 Feng,1936 Yunnan 53 0 1 1 1.9 Lingetal,1936 Yunnan 428 0 0 0 0 Quoted by
Horsfall. 1935 Yunnan 75 0 0 2 2.7 Morin and
Toumannoff, 1933 Yunnan 101 4 5 6 5.9 Robertson. 1940 Monglish, Yunnan 108 1 1 2 1.9 Robertson, 1941
INDIA
Assam Assam 2000 1 0 1 0.04 Ramsay et at., 1936 Cachar (Assam) 125 0 0 0 0 Strickland, 1929 Cachar 888 0 0 0 0 Ramsay, 1930
Bihar Hazanbagh ranges 348 0 0 0 0 Senior White. 1943 Slnghbhum h~lls 89 0 0 0 0 Senior Wh~te and
Narayana, 1940 Singhbhum hills 8 1 0 0 0 0 Senior White and
Das, 1938 Kamataka Mysore 674 2 0 2 0.3 Nursing et a/..
1934 North Kanara 1875 0 0 0 0 Singh and Jacob.
1 944 Kerala Kulasekharam 49 0 0 0 0 Mathew, 1939 Perumpazhuthwr 3559 0 0 0 0 Mathew, 1939 Travancore (Kerala) 3833 3 0 3 0.08 lyengar, 1934 Wyanaad 2494 0 0 0 0 Covell and
Harbhagwan. 1939
Locality Number Number positive dissected GutJGland Gut Gland Total % Source
Madhya Pradesh Bastar district 812 0 0 0 0 Kulkaml 1990 Udaipur 32 0 0 0 0 Roy & B~swas, 1942
Orissa East central India
Jeypore hills Jeypor h~lls Jeypore hills
Jeypore hills Jeypore hills Orlssa
Tamil Nadu Ketti
Senlor Whlte and Ghosh. 1946 Perry, 1914 Senlor Whlte, 1937 Sen~w-White etal., 1945 Senior White, 1945 Par~da et a/. , 1991 Nagpal and Sharma 1986
Russell and Jamb, 1942 do-
Utter Pradesh Na~nital Tenai 7 0 0 0 0 Stndtland and
C howdhuri, 1933 West Bengal 20 0 0 0 0 Fry, 1914
IndoChina Annam 424 3 0 3 0.7 Toumanoff, 1936 Red River Delta 3419 22 18 34 0.99 Gaschen and
Mameff. 1936 do- 2878 27 0.94 Raynal and
Gaschen, 1935 South IndoChina 58 0 1 1 1.72 Toumanoff. 1936 Tonkin 826 4 2 6 0.7 do- Tonkin 133 3 0 3 2.25 Toumanoff, 1932 6
Susceptibility to insecticides
The abundance of An. jeyporiensis adults resting indoors was reduced drastically after
DDT residual spraying in Jeypore hills (Senior White and Ghosh, 1946) and also in Vietnam
(Nguyen-Thuong-Hien, 1968). However, the abundance of this species were not affected by
house spraying with DDT elsewhere in lndia (Pal, 1964), in Hainan (Ho Ch'I and Feng, 1958)
and in Chung-hua district of Kwangtung Province (Lee (La-ge), 1957). Deltamethtin
impregnated bed nets reduced the abundance of An. jeyporiensis upto 95% for more than 180
days in Kwangsi (China), (Xiao Yan el al., 1993). However, information on the susceptibility of
this species to residual insecticide based on direct experiments is still lacking.
Review of literature showed that An. jeyporier~sis has been incriminated as a vector in I
areas of its prevalence outside India. But the role of this species in transmission of human
malaria parasites in India remains unresolved. There are about 30 publications on this species
from lndia Some researchers consider An. jeporiensis as a local vector based on the detection
of oocyst infections, while others consider this species as a 'suspect vector' as there was no
record of sporozoite infections in wild caught specimens. There has been no attempt to explore
the biological and ecological characteristics of this species relating to its capacity to transmit
malaria parasites. Therefore, a holistic approach is needed to assess the vectorial status of An.
jeyporiensis particularly in areas of high malaria prevalence and where the species is abundant