( LITERATURE REVIEW 1

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

Fig. 2. Distribution of Anje~poriemis in India

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