Journal Paper Format

International Journal of Advanced Science and Technology Vol. 28, No. 20, (2019), pp. 1398-1403

A Morphometric Study of Termite Species and their Uses by the Ethnic Tribes in Morigaon District of Assam, India

Kalyan Deka Assistant Professor, Department of Zoology, Pandu College, Guwahati, Assam, India E-mail: [email protected]

Abstract Termites are very small, polymorphic and social insects belonging to the order Isoptera of the class Insecta. Only two species of termites Odontotermes obesus (Rambur) and Odontotermes feae (Wasmann) have been discovered in Morigaon District of Assam during the present survey. The size of Odontotermes obesus is smaller than that of Odontotermes feae. The total body length of soldiers of O. obesus and O. feae are found in the range of (5.0-6.0 )mm and (7.0-8.5) mm respectively. The head-mandible indices of soldiers of O. obesus and O. feae are found in the range of (0.55-0.61) and (0.49-0.56) respectively. The number of antennal segments of soldiers of O. feae is 17 while that of O. obesus is 16. Though these termites are known for pests their alates are used as occasional food by the tribes of Kachari, Karbi and Tiwa.. The different castes of termites along with their nests are used as food for fishes. Their mound-soil is also used for layering the bamboo walls of thatched houses.

Keywords: Odontotermes obesus, Odontotermes feae, alate

1. INTRODUCTION Termites belonging to the order Isoptera of the class Insecta are very small polymorphic, polyphagous and soil inhabiting social insects. They have a good architectural ability (construction of mounds, carton nests, galleries etc.), symbiotic relationships with microorganisms (flagellates, fungus, bacteria, etc.), supporting guests and inquilines in their nests and unique ecological adjustment in the ecosystem [7]. They play contrasting roles of both beneficial as decomposers and harmful as pest in different terrestrial ecosystems damaging crops and woods. Holmgren (1913) [6] was the first to describe the species Odontotermes assamensis [now a synonym of O. obesus (Rambur)] discovered from Assam. The next work on the termites from North-eastern region is that of Silvestry (1914) [12] who recorded four species viz. Odontotermes assamensis Holmgren (syn. of O. obesus), Odontotermes microdens Silvestry, Odontotermes feae (Wasmann) and Nasutitermes moratus (Silvestry), all collected from Abor Hills in Arunachal Pradesh by the Zoological Survey of India. Gardner (1945) [4] described the species Reticulitermes assamensis. Roonwal and Sen-Sarma (1960) [11] described the species Neotermes megaoculatus lakhimpuri from Assam. Genera Macrotermes (4 species), Odontotermes(14 species), Hypotermes(1 species), Microtermes(2 species) and Ancistrotermes (1 species) belonging to the subfamily Macrotermitinae are the most well represented fungus-growing termites in North-eastern India. The genus Odontotermes is most common with 14 species reported in North-eastern India [1]. There are over 2600 species of termites in the world [3]. Three hundred species of termites have been recorded in India [9]. There has been a report of presence of seventy six species of termites in North East India and out of them twenty five species are found in Assam [1]. From the literature it is found that the information regarding uses of termites by different tribes of Morigaon district of Assam, India is not available. The present study aims to have morphometric study of the termite species and to explore their various uses by the ethnic tribes in Morigaon district of Assam. 2. MATERIALS AND METHODS The termites (soldiers and workers) are collected from different locations in Morigaon district of Assam by random sampling. The method of collection and preservation given by Pearce (2006) [8] is followed for the present study. Identification of termites is done with the help of taxonomic keys of Roonwal & Chhotani (1989) [10] and Chhotani (1997) [2]. Identification is mainly based on the characters of soldiers. For identification, termites are normally examined in 70-80% ethyl alcohol in small dishes under binocular

International Journal of Advanced Science and Technology Vol. 28, No. 20, (2019), pp. 1398-1403 microscope. Measurements are taken with the aid of an ocular micrometer. Collection of information from local people is by interview & questionnaire method. 3. THE STUDY AREA Morigaon District is situated in the Brahmaputra Valley of Assam, covering an area of 1551 sq km lying between 91⁰ 57'21"E to 92⁰ 34'9"E longitude and 26⁰ 03'45"N to 26⁰ 31'8"N latitude. It is bounded by the mighty Brahmaputra in the north, Karbi Anglong District in the south, Nagaon District in the east and Kamrup District in the west. The greater part of the district is an alluvial plain with rivers and numerous wetlands. Temperature varies from a minimum of 11.2 ⁰ C to a maximum of 24.8⁰ C in winter and from a minimum of 25.5 ⁰ C to a maximum of 33.9 ⁰ C in summer. The average annual rainfall is about 1600 mm. The study area is mainly inhabited by tribes viz. Kachari, Karbi and Tiwa. 4. RESULTS AND DISCUSSION During the present study two species of termites- Odontotermes obesus and Odontotermes feae are discovered at different locations of Morigaon District of Assam. A) Morphometric description of Odontotermes obesus: i) Soldier of O. obesus: Total body length is in the range of 5.0-6.0 mm. Head is oval and slightly converging in front. Length of head (to base of mandibles) is in the range of 1.30-1.60 mm and maximum width 1.18-1.30 mm. Head pale yellowish brown; thorax and abdomen are yellow to deep brown in colour. Head is thinly and body moderately hairy. Antennae with 16 segments. Labrum is tongue-shaped, with rounded anterior margin with hairs. Mandibles are long, slender and saber-shaped with incurved apices. Left mandible has a sharp, prominent tooth at apical third. Right mandible has a minute tooth a little below the level of tooth on left mandible. Length of mandibles ranges from 0.70mm to 0.80 mm. Postmentum is subrectangular with narrowed anterior portion. Pronotum is saddle-shaped, anterior margin weakly notched; posterior margin also weakly emarginated. Length of pronotum is in the range 0.50-0.60 mm and width 0.80-1.00 mm.

Fig.1: Soldier of Odontotermes obesus : a) Dorsal View of the Total Body b) Dorsal View of the Head.

Fig.2: Diagramatic View of Body Parts of Soldier of Odontotermes obesus : a) Dorsal Side of Head; b) Dorsal View of Pronotum; c) Postmentum;

International Journal of Advanced Science and Technology Vol. 28, No. 20, (2019), pp. 1398-1403 ii) Worker of O. obesus: Total body length is in the range of 2.7-3.5 mm. Head capsule is light yellow to yellowish brown. Head is moderately and body somewhat thickly hairy. Head capsule is subrectangular. Length of the head (to base of mandibles) is in the range 0.80-1.00 mm and maximum width 0.80-0.90 mm. Antennae have 17 segments each. Pronotum is saddle shaped with anterior margin notched. Length of pronotum ranges from 0.33mm to 0.40 mm and width 0.45-0.60 mm. B) Morphometric description of Odontotermes feae: i) Soldier of O. feae: Total body length is 7.0-8.5 mm. Head is yellow to yellowish brown; thorax and abdomen are rusty yellow in colour. Head and body are moderately hairy. Head is subrectangular, longer than wide, sides gradually tapering in front, sometimes almost sub parallel. Length of the head (to the base of mandibles) is 2.4-2.9 mm and the maximum width of the head is 1.9-2.5 mm. Antennae have 17 segments each. Labrum is tongue-shaped with marginal hairs, tapering in front to a pointed tip. Mandibles are stout, strong, saber-shaped, a little longer than half the head-length. Length of mandible is 1.3-1.5 mm. Left mandible has a promnant tooth near its mid position. Right mandible has a minute tooth at basal third. Postmentum is elongated and subrectangular in shape, somewhat swollen near the basal third. Pronotum is saddle-shaped and its anterior margin has a weak median notch; posterior margin has a broad median emargination. Length of pronotum is 0.6-0.8 mm and width 1.2-1.7 mm.

Fig.3: Soldier of Odontotermes feae : a) Dorsal View of the Total Body b) Dorsal View of the Head.

Fig.4: Diagrammatic View of Body Parts of Soldier of Odontotermes feae : a) Dorsal Side of Head; b) Postmentum; c) Dorsal View of Pronotum. ii) Worker of O. feae: Total body length is 5.5-6.0 mm. Head capsule is light yellow to rusty yellow. Head capsule is sub square in shape, a little wider than long; sides are sub parallel. Length of the head (to the base of mandibles) is 1.50- 1.85 mm and maximum width 1.60-2.00 mm. Head is moderately and body fairly hairy. Antennae with 19 segments. Labrum is dome shaped. Pronotum is saddle-shaped, anterior margin has a less promonant median notch; posterior margin with a broad median emargination. Length of pronotum is 0.50-0.60 mm and width 0.80-1.00 mm.

International Journal of Advanced Science and Technology Vol. 28, No. 20, (2019), pp. 1398-1403

Table 1: Measurements (in mm) of Different Body Parts of Soldier of O. obesus and O. feae. Parameters Range of measurement (mm) O. obesus O. feae Length of head to lateral base of mandibles 1.30-1.60 2.40-2.90 Maximum width of head 1.18-1.30 1.90-2.50 Head index (width/length) 0.81-0.90 0.80-0.86 Maximum length of labrum 0.25 0.30 Maximum width of labrum 0.20 0.40 Length of left mandible 0.70-0.80 1.30-1.50 (upper base of condyle to tip) Head-mandibular length Index 0.55-0.61 0.49-0.56 (left mandibles length/head-length) Left mandibular tooth distance 0.22-0.30 0.68-0.80 (base of tooth to tip of mandible) Left mandibular tooth index 0.31-0.37 0.51-0.54 (tooth distance/left mandible length) Maximum length of pronotum 0.50-0.60 0.60-0.80 Maximum width of pronotum 0.80-1.00 1.00-1.30 Pronotum index (length/width) 0.60-0.63 0.60-0.62 No. of antennal segments 16 17

Table 2: Measurements (in mm) of Some Body Parts of Worker of O. obesus and O. feae. Parameters Range of measurement (mm) O. obesus O. feae Total body length 2.7-3.5 5.5-6.0 Maximum length of head (to the base of mandibles) 0.80-1.00 1.50- 1.85 Maximum width of head 0.80-0.90 1.60-2.00 Maximum length of pronotum 0.33-0.40 0.50-0.60 Maximum width of pronotum 0.45-0.60 0.80-1.00 No. of antennal segments 17 19 The obtained range of measurements of different body parts of soldier of Odontotermes obesus and Odontotermes feae mentioned in the table 1 are within the range of measurement reported by Mukherjee et al.(2008) [7] except the length and width of pronotum of O. feae which show a little variation from the known range. The number of antennal segments has been observed higher in workers than that of soldiers in the both species. The soldier of O. obesus has 16 antennal segments while the worker has 17 segments. In case of O. feae the soldier has 17 antennal segments while the worker has 19 segments. It is evident from the table 1 & 2 that the size of both soldier and worker of Odontotermes feae is larger than that of Odontotermes obesus. But the head-mandible indices of soldiers of O. feae (0.55-0.61) are found higher than that of O. obesus (0.49-0.56). C) Uses of Termites by ethnic tribes: Though termites are pests of plantations and forestry these are used by the tribes of the present study area for different purposes. i) As food for man: Alates are used as occasional food by Kachari, Karbi and Tiwa tribes. 66.9 percent of Kachari, 59.1 percent of Karbi and 40 percent of Tiwa tribe use alates as food. Queens are also eaten when available. Traditional method of collection of alates and processing for food: The alates are easily gathered at the beginning of the rainy season or when they swarm. As they are attracted to light they can be gathered up when they land on nets put up around a lamp. They are also caught by keeping a big container with water around a lamp.

International Journal of Advanced Science and Technology Vol. 28, No. 20, (2019), pp. 1398-1403

The wings are shed and can be removed easily. They are best gently roasted on a hot plate or lightly fried until slightly crisp. ii) As food for fishes: These species of termites (workers, soldiers, queen) along with their nests are used by some people (non-tribes also) as food for fishes. iii) Use of mound-soil: A few people of some villages use mound-soil for layering the bamboo walls of their thatched houses. A mixture of mound soil and cow dung is prepared for the purpose.

Table 3: Percentage of People Using Different Stages of Termites for Different Purposes. Uses Termite stages Percentage of Tribal people Percentage of Non- Kachari Karbi Tiwa tribal people As food for man Alates 66.9 59.1 40.0 0 Queen 6.0 7.0 5.2 0 Soldiers & 0 0 0 0 Workers As food for fishes Soldiers & 4.3 3.5 12.2 2.6 workers along with nest Mound soil for layering -- 5.2 6.0 1.7 0 bamboo walls of thatched house From the table 3 it has been found that alates are used as food by majority of Kachari people with highest percentage (66.9%) followed by Karbi and Tiwa people. None from the non-tribal people has been found to consume termites. A few percentages of people from all the groups has been found to use termites as food for fishes. CONCLUSION The termite species found in Morigaon District of Assam during the present survey are Odontotermes obesus (Rambur) and Odontotermes feae (Wasmann). The size of O. obesus is smaller than that of O. feae. The total body length of soldiers of O. obesus and O. feae are found in the range of (5.0-6.0) mm and (7.0- 8.5) mm respectively. The number of antennal segments has been observed higher in workers than that of soldiers in both species. Their alates are used as food by the tribes of Kachari, Karbi and Tiwa. The different castes of termites along with their nests are used as food for fishes. Their mound-soil is also used for different purposes. It needs further study to investigate the nutritional value of alates. References [1] G. Bose, “Termite fauna of North Eastern India.”, Occ. Pap. Rec. Zool. Surv. India, No. 171, (1999), pp. 1-20 & 143-145. [2] O.B. Chhotani, “Fauna of India-Isoptera (Termites)”, Publ. Zool. Surv. India, Vol. II., (1997) [3] E. A. Firouzabadi, B. Habibpour, H. Galehdari and P. Shishehbor, “Genetic diversity and morphometric study of thirteen populations of Microcerotermes diversus (Silvestri) (Isoptera: Termitidae) in southern Iran”, Proceedings IRG Annual Meeting (ISSN 2000-8953), (2012) [4] J. C. M. Gardner, “ New Termitidae from India and Burma (Isoptera)”, Indian J. Ent., vol. 6 (1-2), (1945), pp. 103-110. [5] N. Holmgren, “Termites from British India (Bombay) collected by Dr. J. Assmuth”, J. Bombay nat. Hist. Soc., vol. 21 (3), (1912), pp. 774-793. [6] N. Holmgren, “ Termitenstudien. 4. Versuch einer Systematischen Monographie der Termiten der orientalischen Region”, K.svenska Vetensk-Akad. Handl., vol.50(2), (1913), pp. 1-276. [7] P. Mukherjee, P.K. Maiti and N. Saha, “Termite (Isoptera) Fauna of the Himalaya including its Zoogeographical Analysis”, Memoirs of the Zool. Surv. India, Vol. 21 (2), (2008), pp. 2-15; 123-124 & 136-138.

International Journal of Advanced Science and Technology Vol. 28, No. 20, (2019), pp. 1398-1403

[8] M.J. Pearce, “ Termites (Biology and Pest Management)”, Publ. CAB International, (2006), pp. 123- 126. [9] D. Rajagopal , “33 Economically important termite species in India”, Sociobiology, vol. 40, (2002), pp. 33-46. [10] M. L. Roonwal and O. B. Chhotani, “Fauna of India-Isoptera (Termites)”, Publ. Zool. Surv. India. Vol. I., (1989) [11] M. L. Roonwal and P. K. Sen-Sarma, “Contributions to the systematic of Oriental Termites”, New Delhi (Ent. Monogr. No. 1, Indian Counc. Agric. Res.). xiv + 407 pp. (65 pls) (1960) [12] F. Silvestry, “ Zoological results of the Abor Expedition, 1911-12, XXXII. Termitidae” Rec. Indian Mus., vol. 8(5), (1914), pp. 425-435.