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A PRELIMINARY INVENTORY AND COMPARISON STUDY OF TERMITES AT TWO DISTANT LOCATIONS IN MYSORE CITY

posted Feb 20, 2018, 2:14 AM by Sharath Adavanne   [ updated Feb 20, 2018, 4:14 AM ]

Introduction

An effort made to understand the co-existence of termite population in two different locations under an aggravating urbanization is presented here. The result expresses Termite miscellany of two locations. Totally eight species have been documented of which four are present in Regional Museum of Natural History premises and seven in Roopa Nagar Residential Layout. The reason behind the absence of few species at two different locations is required to be ascertained in future studies.

Study Area

The Regional Museum of Natural History (RMNH) is located in Mysore, Karnataka situated on the south-eastern part of Mysore City adjoining Karanji Lake. Spread over an area of 2 acres, RMNH premises houses a well-maintained garden supporting plants and grass to tree varieties. It supports diverse life forms - insects, mammals, reptiles, mollusks and rich in organic materials includes 26 butterfly and 32 bird species. Here symptoms of termite presence found seasonally. Since the museum has adopted “No Pesticides” policy, recorded a number of Termite trails in the natural cover on the garden flooring.

Roopa Nagara (RNRC) is a recently planned residential Colony sprawling about 100 hectares and on the western outskirts of Mysore city. The area studded with a scanty population of mango and coconut cultivation along with other native species of Ficus, Pongamia and Acacia converted into a planned residential colony. Predominantly this area is surrounding by numerous human settlements. This area does not have any open water bodies.

Method & Results

The RMNH, once a barren land with few thorny shrubs and clumps of grass had been converted into arable and varieties of plants have been planted in the past 22 years. As the maintenance and other activities produce heaps of organic wastes, it attracted a number of insect forms to dwell in. Thus termites also had an opportunity to hold their colonies.

Whereas, the RNRC is a human settlement, studded with numerous termite occupations and being transformed into a new gardening plot. The agricultural and horticulture fortifications are ably holding up the termite fauna.

Termite samples were collected from both the areas in different seasons of the year beginning with the year 2006 till 2014. Usually, samples were collected in the field just after sunrise when they are more active. The insects were picked up by using soft round brush (usually number 03 denomination) and put into vials containing 70% alcohol which is the best and time-tested preservative for these soft-bodied insects, and when collections made in a greater number i.e. from excavation of a mound, the lot was preserved in a cold box and later transferred in to alcohol preservative. On each collection prepared field notes with details like location, time, nature of the nest - mound/ bark/ underneath stone/dry dung; weather –sunny/rainy/ after rains etc..

Around 100 vials of termite samples were sent for taxonomic identification to Zoological Survey of India (ZSI), Kolkata. The report confirms identification. The termite samples have been deposited vide ZSI -55/2016 for future references and further studies.

Table: Termite species recorded in RMNH and RNRC

RMNH

RNRC

Not recorded

Odontotermes brunneus

Not recorded

Odontotermes obesus

Not recorded

Odontotermes feae

Odontotermes bellahunisensis

Odontotermes bellahunisensis

Odontotermes horni

Odontotermes horni

Odontotermes ceylonicus

Not recorded

Not recorded

Odontotermes wallonensis

Trinervitermes nigrirostris

Trinervitermes nigrirostris



Brief description of Species

Termites construct three types of nests:
  • Nests below ground level –underground / subterranean 
  • Mounds - above ground level 
  • Arboreal nests – on trees, high stumps ... 

The higher termites (Termitidae) build terrestrial nests, above ground, which houses a large fungus garden, but there are subterranean nest builders too.

Each species have specialized a fastidious architectural pattern of nest building to suit its lifestyle, basically, the mound patterns may be classified into unilocular, where a nest has a large central cavity and in multilocular pattern several cavities. This is further divided into fungus growers and non-fungus growers.

The most common and important mound building termites in south India are;
  • Odontotermes obesus (recorded in present study area) 
  • Odontotermes redemanni (not recorded in present study area) 
  • Odontotermes wallonensis (recorded in present study area) 
Out of these, Odontotermes obesus build very tall and conspicuous subcylindrical mound, with series of buttress supporting the structure all around.

Further termites are recognized as larger species and smaller species based on the head length to the base of mandibles. If it is more than 2.0mm they are placed under larger species. 



Outlines of genus Odontotermes and genus Trinervitermes, that are dealt in this article.

Genus: Odontotermes
  • Head: pale yellow-yellowish brown coloration; sparsely hairy head, and fairly densely hairy body 
  • Head-capsule: oval or subrectangular, converging in front. 
  • Fontanelle indistinct 
  • Antennae –with 15 -18 segments 
  • Labrum- Tongue shaped, anteriorly either rounded, at anterior margin or narrowed to a sharp or bluntly rounded tip 
  • Mandibles-delicate to strong and stout. 
  • Left mandible-with a small, rudimentary to a large and prominent tooth situated at variable positioned on inner margin. 
  • Right mandible – the presence of a small, rudimentary corresponding tooth. 
  • Postmentum –subrectangular, weakly to strongly arched, sides sub straight to strongly convex. 
  • Pronotum – saddle-shaped

Genus: Trinervitermes – Soldier - Dimorphic: Soldier Major and Soldier Minor
    1. Soldier Major 
  • Head – with along cylindrical rostrum narrowing towards anterior end. 
  • Antennae –with 12-14 segments 
  • Mandibles – vestigial without any spinous process. 
  • Pronotum – strongly saddle-shaped
  • Legs – moderately long, hairy. 
  • Abdomen –Elongated. 
    2.    Soldier Minor resembles the major in many respects
  • Head capsule elongated pyriform to subrectangular
  • Rostrum – narrow, cylindrical and much lengthier, compared to head length than in major. 
  • Antennae - 12-14 segments, longer in comparison to soldier major


1: Odontotermes obesus
(Rhambür)

1

Total body length

4.0-6.0 mm

2


Head

Head capsule

Head sparsely hairy

Oval, weakly converging anteriorly, Head capsule Pale yellow to castaneous brown colored

3

Antennae

Pale yellow to yellowish brown, darker distally, Two types antennae(a)antennae with 16 segments(b)antennae with 17 segments. In 16 segmented antennae, segment 2 is sub equal to segment 3 and 4, and in 17 segmented antennae, segment 3 is the shortest.

4

Labrum

Tongue-shaped, with broadly rounded anterior margin

5

Mandibles

Long, slender, sabre-shaped.

6

Left mandible

With a sharp, prominent tooth at distal ⅓

7

Right mandible

With a minute tooth, a little below the level of the tooth on the left mandible.

8

Postmentum

Sub rectangle

9

Pronotum

Saddle shaped, anterior lobe semi circular, anterior margin weakly to deeply notched. Posterior margin also weakly emarginate to distinctly notched.

There are dimorphic working caste (1) worker major and (2) worker minor 


2: Odontotermes wallonensis (Wassmann)






1

Total body length

4.6-6.7 mm

2

  1. Head

  2. Head capsule

Head sparsely hairy

Sub rectangularly oval, sides faintly convex, pale yellow to brownish yellow in colour.

3

Body and legs

Body densely hairy, whitish to yellowish in color

4

Antennae

Yellow to pale brown distally and paler proximally, antennae two types with 16 segmented and 17 segmented. in 16 segmented antennae, segment 2 is sub equal to segment 3,and segment 4 is shortest. In 17 segmented antennae, segment 2 is longer than segment3 and segment 3 is the shortest and segment 4 is longer than segment 5.

5

Post clypeus

Not clearly de marketed, faintly marked on sides, with a few hairs.

6

Labrum

Broadly tongue shaped, anteriorly broadly rounded.

7

Mandibles

Long, fairly strong and incurved anteriorly.

8

Left mandible

With a prominent tooth, a little above middle point.

9

Postmentum

Sub rectangular and flat.

10

Pronotum

Saddle-shaped, deeply notched, both anteriorly and posteriorly.

11

Mesonotum

Narrower than Pronotum.

12

Metanotum

As wide as /broader than Pronotum, posterior margin sub straight/weakly incurved.

There are dimorphic working caste (1) worker major and (2) worker minor. This is a common mound-building termite. The mounds are noticeable with their chimney like openings and commercially termed as agriculture pest.


3: Odontotermes ceylonicus (Wasmann)




1

Total body length

5.0-7.4mm

2

  1. Head

  2. Head capsule

Head sparsely hairy. Head capsule subrectangular, sides sub straight/ fairly convex and very slightly converged in front of antennae. The colouration of head capsule is yellow to brown.

3

Antennae

Antennae two types, 16 segments and 17 segments. In 16 segmented, segment 4 is the shortest segment and in 17 segmented, segment 3 is the shortest.

4

Labrum

Sub triangular, with tip somewhat pointed

5

Mandibles

Strong, stout, saber-shaped and incurved at tips.

6

Left mandible

With a large ,sharp pointed tooth at middle, making an angle of about 90⁰

7

Right mandible

With a rudimentary tooth at middle

8

Postmentum

Saddle –shaped, anterior and posterior margins deeply emarginate in middle.

There are dimorphic working caste (1) worker major and (2) worker minor. The nests of Odontotermes ceylonicus are subterranean, for foraging they make covered runways and lays sheaths of earth over the tree trunks feeding on the bark.


4: Odontotermes horni (Wasmann)




1

Total body length

Total body length including mandibles 6.7-10.4 mm

2

  1. Head

  2. Head capsule

Head sparsely hairy, yellow to reddish brown.

Head capsule sub rectangular, sides, sub straight, very slightly converged in front of antennae.

3

Abdomen, body and legs

Abdomen creamish white to pale yellow, body fairly hairy, legs creamish white.

4

Antennae

Pale yellowish coloured, 17 segmented. Segment 3ia much shorter than segment 2, segment5is shorter than segment 4. Segment 4 is almost as long as segment 2.

5

Pronotum

Pale yellowish brown, saddle shaped, anterior margin with weak to moderately marked median notch; posterior margin reasonably distinctly notched.

6

Labrum

Pale yellowish to yellowish brown colored.

7

Mandibles

Strong, stout and sabre-shaped.

8

Left mandible

A large, prominent tooth near the base of the middle third.

9

Right mandible

With a minute tooth, a little below the level of the tooth on the left mandible.

There is dimorphic working caste (1) worker major and (2) worker minor.



5: Odontotermes bellahunisensis Holmgren and Holmgren



1

Total body length

Including mandibles 3.60-5.60 mm. Body densely hairy.

2

Head and Head capsule

Head broadly oval, broadest posteriorly and narrowed in front. Head sparsely hairy, Head-capsule brownish yellow, subcircular.

3

Antennae

There are two types 16 segmented and 17 segmented. Segment 4 is shortest in 16 segmented one, and segment 3 is shortest in 17 segmented antennae. Antennae are yellowish brown coloured.

4

Mandibles

Short, stout, sickle-shaped and strongly incurved, distally shorter in comparison to head.

5

Left mandible

With a large pointed tooth at distal third.

6

Right mandible

With a minute tooth, a little above middle.

7

Pronotum

Saddles shaped, anteriorly weakly notched, and posteriorly sub straight.

8

Mesonotum

Narrower and Metanotum is wider than Pronotum, posteriorly no emargination.

There is dimorphic working caste (1) worker major and (2) worker Minor. This species is a subterranean dweller.

Continue to read part 2