J. Ent. Res. Soc. 6(2): 1-13, 2004 ISSN:1302-0250

Mosquito Diversity in Rajiv Gandhi National Park (Nagarahole), Karnataka State,

Yadurappa SATHISH KUMAR Nagabhushanrao GANESH Achuthan VIJAYAN

University of Mysore, Department of Studies in Zoology, Manasagangothri, Mysore-570 006, INDIA, e-mail: [email protected]

ABSTRACT One year long study was conducted to document the diversity of species in a national park of Karnataka State, India for the first time. A total of 60 species belonging to 10 genera were recorded. Seventeen different larval habitats were identified in the national park. Genus was predominant with a maximum number of 21 species followed by Aedes with 12 and Anopheles with 10 species respectively. Aedes albopictus, An. barbirostris, An. vagus, Cx. fuscanus, Cx. fuscocephala and Cx. mimulus were found throughout the year. Maximum number of species was found to breed in ponds. Of the total number of species recorded, 14 are known to be vectors of different mosquito-borne diseases in India.

Key words: Forest, mosquitoes, diversity, larval habitats

INTRODUCTION Rajiv Gandhi National Park is one of the hot spots for wild life in the Nilgiri biosphere and lies between latitude 11o 50’N to 12o 15’ N and longitude 76o 0’ to 76o 20’E on the eastern slopes of Western Ghats (Fig. 1). The national park covers an area of 643.4 sq. km with a core zone of 192 sq. km and a tourism zone of 110sq. km. The terrain is undulating with an altitude ranging from 701 to 959 mts. The climate here is tropical with an annual rainfall of 1194.7 mm. The forest type comprises of southern tropical mixed deciduous- both moist and dry – with small patches of semi evergreen type. It also includes 900ha of teak plantations and degraded scrub forests on the eastern parts. There are several swampy areas within 2 SATHISH KUMAR, B. Y., GANESH, K. N., VIJAYAN, V. A. the forest. Hills and extended forest areas surround the National Park. About 50 tribal settlements are situated in the Park and these tribals are fully dependent on forest for their livelihood. Mosquitoes of south India was documented first in the monographs of Barraud (1934) and Christophers (1933) and a very few subsequent reports were made by Russel and Jacob (1942) from the Nilgiris; Covell and Harbhagwan (1939) and Vedamanikkam (1949, 1952) in the Wynaad area; Ramachandra Rao (1945); Jaswant Singh and Jacob (1944) in North Kanara Districts; Brooke Worth (1953) in Hassan district and Tewari et al. (1987) in Western Ghats of Tamilnadu. Since then, many ecological changes have occurred in this region and such changes would reflect on the biodiversity of the region including those of mosquito species. Biodiversity conservation needs the base line data of all fauna and flora, even the lesser known groups, as all have to play their own role as producers, consumers, pollinators and decomposers. These diverse forests with micro and macro climatic conditions, harbours a variety of invertebrate fauna including mosquitoes that play a significant role in conserving and maintaining biodiversity in the National park. The present study which formed a part of “India Eco-development project” funded by World Bank through Karnataka State Forest Department was conducted to document the current status of mosquito biodiversity in the National Park.

MATERIALS AND METHODS The study was carried out from October 2001 to September 2002. Both larvae and adult mosquitoes were collected from more than 50 localities of the National Park (Fig.1) and each locality was sampled at least once in each season (Winter- October to January, Summer- February to May and Rainy- June to September). Immatures were collected using a dipper (size-14x6cm) in ground pools and other open sources and Pasteur pipette in tree holes and other container habitats. They were transferred to plastic containers with water from the respective habitats. Eggs were also collected in some instances and brought to the laboratory for rearing and identification. Larval and pupal specimens were examined fresh or slide mounted using Hoyer’s medium. Adults were mounted on minuten and wherever necessary terminalia were mounted on slide. Species identification was done following the keys of Christophers (1933), Barraud (1934), Ramachandra Rao (1974), Reinert (1974), Sirivanakarn (1976) and Huang (1979). Preserved specimens were also sent to Culicid Biodiversity cell,Vector Control Research Centre (ICMR), Pondicherry for confirmation and deposition. Mosquito Diversity in Rajiv Gandhi National Park (Nagarahole), Karnataka 3 RESULTS A total of 60 species belonging to 10 genera viz., Aedes, Anopheles, Armigeres, Culex, Mansonia, Mimomyia, Ochlerotatus, Toxorhynchites, Uranotaenia and Verrallina was recorded (Table 1) from collections made during the study period. One of the Aedes and Verrallina specimens could be identified only up to subgenus level. Breeding of about 30 species was recorded only during monsoon season (June-September). Aedes albopictus, An. barbirostris, An. vagus, Cx. fuscanus, Cx. fuscocephala and Cx. mimulus were found breeding in all the seasons i.e., monsoon, winter and summer. The species recorded in relation to the larval habitats are given in Table 2. Only 4 species viz., An. barbirostris, An. vagus, Cx. fuscocephala and Cx. fuscanus were found in more than 5 types of larval habitats. A maximum number of 26 species were found in the pond habitat with tree holes ranking next with 15 species. Species composition found in different larval habitats is presented in Table 3. It was observed that, An. barbirostris, An. annularis, An. philippinensis, An. vagus have shared breeding habitats with Cx. fuscanus,Cx. vishnui, Cx. pseudovishnui and Ma. annulifera while Ae. albopictus was found breeding with Oc. chrysolineatus and Oc. gubernatoris. The larvae of Ma. annulifera was found attached to the roots of aquatic plant Pistia stratiotes (Fam: Araceae). Cx. fuscanus has exploited almost all types of habitats (ground water habitats) in association with one or more mosquito species.

CONCLUSION AND DISCUSSION The National Park has a very rich and diversified mosquito fauna represented by 60 species. Among them genus Culex was predominant with a maximum number of 21 species and found to exploit variety of larval habitats, followed by Aedes with 12 and Anopheles with 10 species.Toxorhynchites, Mansonia and Mimomyia were represented by only one species each. Maximum number of species was found in ponds. Among Anopheles, An. barbirostris and An. vagus larvae were found in all the ground water habitats except in sandy pools. Most of the Culex species were also found in ground water habitats. All the Ochlerotatus members were tree hole breeders. Anopheles vagus was present in all the ground pools as reported earlier by Malhotra et al., (1987) from Arunachal Pradesh. Similarly the sharing of habitat by An. philippinensis, An. vagus and Cx. vishnui found here is in line with an earlier report by Malhotra et al., (1987). Of the 60 species recorded in this study, 14 are known to be vectors of different mosquito- 4 SATHISH KUMAR, B. Y., GANESH, K. N., VIJAYAN, V. A. borne diseases in India. They are Ae. albopictus and Ae. aegypti (dengue fever); An. annularis, An. dirus, An. philippinensis, An. leucosphyrus (malaria); Cx. bitaeniorhynchus,Cx. gelidus,Cx. fuscocephala,Cx. tritaeniorhynchus,Cx. vishnui, Cx. pseudovishnui (Japanese encephalitis); Cx. quinquefasciatus (Bancroftian filariasis) and Ma. annulifera (Malayan filariasis). Anopheles dirus has been recorded earlier by Kalra and Wattal (1962) in North Kanara and in Nilgiri hills by Tewari et al., (1987). Anopheles vagus and Ae. pseudotaeniatus were also recorded from forest area of Orissa (Yadav et al., 1997). Khan et al., (1998) placed Cx. quinquefasciatus and Cx. tritaeniorhynchus under non forest species list but in our study we found them in the forest area as well. An. dirus, An. philippinensis, An. tesselatus, Ae. alboscutellatus, Ar. subalbatus, Cx. gelidus and Cx. pallidothorax have been reported from the forests of Northeastern India as well. Tewari et al., (1987) recorded 6 Anopheline species from tree holes in Nilgiris, but in the present study tree holes did not yield any Anopheline species. Yadav et al., (1997) have recorded Cx. mimulus in tree holes and found An. vagus, Ae. pseudotaeniatus and Ar. subalbatus breeding in forest only. In our study area Ae. albopictus was the most common tree hole breeder as in the forest ecosystem of Orissa State (Yadav et al., 1997), Nilgiri hills (Rahman et al., 1973) and Gujarat State (Srivastava, 1989). It is well known that some of the mosquitoes which were originally zoophilic and sylvatic have adapted to feeding on humans and became peridomestic and even periurban due to deforestation. The involvement of man in certain host-parasite cycles will depend on the effect of his activities on the breeding sites of vectors, their capacity to adapt to new ecology and the presence of reservoirs as well as human behaviour pattern. Due to extensive deforestation in Himalayan submountain belt of India and and development of intensive agriculture, An. culicifacies has replaced An. fluviatilis as the main vector of malaria, breeding prolifically in river-bed pools, burrow pits and irrigation canals with an inevitable sharp deterioration in the malaria situation (Sharma et al., 1984). Likewise in western Africa, deforestation and irrigation have been followed by an increase in Plasmodium falciparum malaria transmitted by An. gambiae in villages close to forest (Patz et al., 2000). Similarly in Southeast Asia, different species complexes, An. dirus, An. minimus, An. balabacensis have been affected in different ways by forest clearance with different impacts on malaria incidence (Walsh et al., 1993). Mosquito Diversity in Rajiv Gandhi National Park (Nagarahole), Karnataka 5 In India, Aedes albopictus, a vector of dengue haemorrhagic fever was a sylvatic species as found in the present survey, but it has been shown to be adapted to more or less similar aquatic biotypes in an urban garden (Ray and Tandon, 1999). Further it has been demonstrated by many authors that several major groups of vectors including mosquitoes are directly affected by deforestation and are capable of establishing at different ecological conditions created by man. So one should be very cautious about the effect of deforestation on vector breeding and its impact on both human and wild life population. The occurrence of a rich and diversified fauna in some parts of Nilgiri Biosphere region where Rajiv Gandhi National Park is situated is largely due to the conservation of virgin forest in this region. Continuation and adoption of strict conservation strategies for forest biome in this region is very essential in order to safeguard the rich genetic diversity, since human interference is likely to extend within the region as it is evident at the fringes of the forest area.

Table 1. List of mosquito species of Rajiv Gandhi National Park, Karnataka, India.

1. Aedes (Aedimorhphus) alboscutellatus (Theobald) 1905 2. Aedes (Aedimorhphus) caecus (Theobald) 1901 3. Aedes (Aedimorhphus) jamesi (Edwards) 1914 4. Aedes (Aedimorhphus) pipersalatus (Giles) 1901 5. Aedes (Aedimorhphus) syntheticus Barraud 1928 6. Aedes (Fredwardsius) vittatus (Bigot) 1861 7. Aedes (Neomelaniconion) lineatopennis (Ludlow) 1905 8. Aedes (Stegomyia) aegypti (Linnaeus) 1762 9. Aedes (Stegomyia) albopictus (Skuse) 1894 10. Aedes (Stegomyia) w-albus (Theobald) 1905 11. Aedes sp. (unidentified) (sub genus: Diceromyia) 12. Aedes (Christophersiomyia) annulirostris (Theobald) 1905 6 SATHISH KUMAR, B. Y., GANESH, K. N., VIJAYAN, V. A. Table 1 continued

13. Anopheles (Anopheles) barbirostris Van der Wulp 1884 14. Anopheles (Cellia) annularis Van der Wulp 1884 15. Anopheles (Cellia) dirus Peyton and Harrison 1979 16. Anopheles (Cellia) jamesi Theobald 1901 17. Anopheles (Cellia) pallidus Theobald 1901 18. Anopheles (Cellia) philippinensis Ludlow 1902 19. Anopheles (Cellia) subpictus Grassi 1899 20. Anopheles (Cellia) tessellatus Theobald 1901 21. Anopheles (Cellia) vagus Doenitz 1902 22. Anopheles (Cellia) leucosphyrus Doenitz1901 23. Armigeres (Leicesteria) flavus (Leicester) 1908 24. Armigeres (Armigeres) subalbatus (Coquillett) 1898 25. Armigeres (Leicesteria) magnus (Theobald) 1908 26. Culex (Culex) bitaeniorhynchus Giles 1901 27. Culex (Culex) cornutus Edwards 1922 28. Culex (Culex) fuscocephala Theobald 1907 29. Culex (Culex) gelidus Theobald 1901 30. Culex (Culex) infula Theobald 1901 31. Culex (Culex) mimulus Edwards 1915 32. Culex (Culex) perplexus Leicester 1908 33. Culex (Culex) quinquefasciatus Say 1823 34. Culex (Culex) tritaeniorhynchus Giles 1901 35. Culex (Culex) whitei Barraud 1923 Mosquito Diversity in Rajiv Gandhi National Park (Nagarahole), Karnataka 7

Table 1 continued

36. Culex (Culiciomyia) bailyi Barraud 1934 37. Culex (Culex) hutchinsoni Barraud 1924 38. Culex (Culiciomyia) nigropunctatus Edwards 1926 39. Culex (Culiciomyia) pallidothorax Theobald 1905 40. Culex (Culiciomyia) scanloni Bram 1967 41. Culex (Eumelanomyia) foliatus Brug 1932 42. Culex (Eumelanomyia) malayi (Leicester) 1908 43. Culex (Lophoceraomyia) wilfredi Colless 1965 44. Culex (Lutzia) fuscanus Widemann 1820 45. Culex (Culex) vishnui Theobald 1901 46. Culex (Culex) pseudovishnui Colless 1957 47. Mansonia (Mansonioides) annulifera (Theobald) 1901 48. Mimomyia (Etorleptiomyia) luzonensis (Ludlow) 1905 49. Ochlerotatus (Finlaya) chrysolineatus (Theobald) 1907 50. Ochlerotatus (Finlaya) cogilli (Edwards) 1922 51. Ochlerotatus (Finlaya) gubernatoris (Giles) 1901 52. Ochlerotatus (Finlaya) harveyi (Barraud) 1923 53. Ochlerotatus (Finlaya) lophoventralis (Theobald) 1910 54. Ochlerotatus (Finlaya) pseudotaeniatus (Giles) 1901 55. Ochlerotatus (Finlaya) pulchriventer (Giles) 1901 56. Toxorhynchites (Toxorhynchites) splendens Wiedmann 1819 57. Uranotaenia (Pseudoficalbia) bicolor Leicester 1908 58. Uranotaenia (Uranotaenia) campestris Leicester 1908 59. Verrallina (Neomacleaya) cauta Barraud 1928 60. Verrallina sp. 8 SATHISH KUMAR, B. Y., GANESH, K. N., VIJAYAN, V. A.

Table 2. Mosquito species of Rajiv Gandhi National Park in relation to larval habitats.

HABITATS

SPECIES lit bamboo bamboo lit p Bamboo stump Bamboo pool Mud hole Tree blade Leaf pool Spring Pond Rain water pool Sandy pool print foot Elephant S Streams Streams Seepages Rocky pool tank Cement shell Fruit River Lake

1. Aedes alboscutellatus + + 2. Aedes caecus + 3. Aedes jamesi + + 4. Aedes pipersalatus + 5. Aedes syntheticus + + + 6. Aedes vittatus + 7. Aedes lineatopennis + 8. Aedes aegypti + 9. Aedes albopictus + 10. Aedes w-albus + 11. Aedes sp. + (unidentified) 12. Aedes annulirostris + 13. Anopheles + + + + + + + + + barbirostris 14. Anopheles annularis + + 15. Anopheles dirus + 16. Anopheles jamesi + + + 17. Anopheles pallidus + + 18. Anopheles + + philippinensis 19. Anopheles subpictus + + + + 20. Anopheles tessellatus + 21. Anopheles vagus + + + + + + + + + 22. Anopheles + + leucosphyrus 23. Armigeres flavus + 24. Armigeres subalbatus + 25. Armigeres magnus + 26. Culex + + bitaeniorhynchus 27. Culex cornutus + + 28. Culex fuscocephala + + + + + + 29. Culex gelidus + 30. Culex infula +

Mosquito Diversity in Rajiv Gandhi National Park (Nagarahole), Karnataka 9

Table 2 continued

Bamboo stump stump Bamboo Mud pool Tree hole blade Leaf Spring pool Pond poolRani water Sandy pool printElephant foot Split bamboo Streams Seepages poolRocky Cement tank shell Fruit River Lake

31. Culex mimulus + + 32.Culex perplexus + 33. Culex quinquefasciatus + 34. Culex tritaeniorhynchus + 35. Culex whitei + 36. Culex bailyi + 37. Culex hutchinsoni + 38. Culex nigropunctatus + 39. Culex pallidothorax + + 40. Culex scanloni + 41. Culex foliatus + 42. Culex malayi + 43. Culex wilfredi + 44. Culex fuscanus + + + + + + + + + + 45. Culex vishnui + 46. Culex pseudovishnui + 47. Mansonia annulifera + 48. Mimomyia luzonensis + 49. Ochlerotatus + + chrysolineatus 50. Ochlerotatus cogilli + 51. Ochlerotatus + + gubernatoris 52. Ochlerotatus harveyi + 53. Ochlerotatus + lophoventralis 54. Ochlerotatus + + pseudotaeniatus 55. Ochlerotatus + + + + pulchriventer 56. Toxorhynchites + splendens 57. Uranotaenia bicolor +

58. Uranotaenia campestris +

59. Verrallina cauta + 60. Verrallina sp. + (unidentified)

10 SATHISH KUMAR, B. Y., GANESH, K. N., VIJAYAN, V. A. Table 3. Association of species found in different larval habitats in Rajiv Gandhi National Park.

Mosquito species ictus ictus p Ae. albo Ae. Ae. syntheticus An. barbirostris An. annularis An. philippinensis An. vagus Ar. subalbatus Cx. fuscocephala Cx. mimulus bitaeniorhynchus Cx. Cx. nigropunctatus Cx. fuscanus Cx. vishnui Cx. pseudovishnui Mansonia annulifera Oc. chrysolineatus gubernatoris Oc. Tx. splendens

Ae. Albopictus + + +

Ae. syntheticus + + +

An. barbirostris + + + + + + + + + +

An. annularis + + + + + +

An. philippinensis + + + + + +

An. vagus + + + + + + + + +

Ar. subalbatus +

Cx. fuscocephala + + + + + +

Cx. mimulus + + + +

Cx. bitaeniorhynchus + +

Mosquito Diversity in Rajiv Gandhi National Park (Nagarahole), Karnataka 11

Fig.1. Map showing the water holes and streams in Rajiv Gandhi National Park. 12 SATHISH KUMAR, B. Y., GANESH, K. N., VIJAYAN, V. A. ACKNOWLEDGEMENT Authors are thankful to Karnataka State Forest Department for financial assistance, Vector control Research Centre (ICMR), Pondicherry, India for confirmation of species identification and Chairman, Department of Studies in Zoology, University of Mysore, Mysore, India for the facilities provided.

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Received: December 04, 2003 Accepted: March 15, 2004