Nagarahole National Park
Nagarahole is one of the most important National Parks of India and Asia. It has emerged as one
of the last safe asylums for the Asian Elephant, whose future has become uncertain. The precious
tracts of deciduous forests of Nagarahole are also a forte for the Royal Bengal Tiger, which is
on the verge of extinction in India and elsewhere. The National Park that sprawls over 643 sq.kms
derives its name from a small river called "Nagarahole", which means “Serpentine River” in Kannada.
The Brahmagiri Mountains, an integral part of the Western Ghats form a permanent backdrop to
Nagarahole in the South.
Insect Systematics And Conservation
Insects form the bulk of the biodiversity and they play a crucial role in ecosystem functioning,
like pollination, herbivore decomposition and are important prey base for wide range of animals
right from insects, birds and to even mammals. Many species of insects are highly endemic and are
sensitive to any habitat disturbances and even to microclimatic changes. However, very little is
known about the degree of loss in their diversity and the extent to which tropical forest management
can minimize their loss. Because of their small size and modest needs, most insects and other
invertebrates occupy ecological niches that are more numerous and smaller in all dimensions
and more sensitive than those of vertebrates. Insect diversity is positively correlated to
stand level density and diversity. Simplification of stand diversity and structure of
uncultivated areas adjacent to cultivated land can cause imbalance on pest and natural enemy
guilds. So it is critical to understand the effects of various ecosystem processes play in
maintaining the species diversity and composition of insects to formulate a better conservation
strategy and agricultural practices.
Insect taxonomists of ATREE are involved in the inventory, identifying and databasing of many
lesser-known insect taxa of various protected areas. Inventory and taxonomy are the basics to
understand biodiversity taxonomic database is the core reference system and knowledge base upon
which all discussion on conservation rests. Inventories provide baseline information for the
assessment of change and data for conserving and managing biodiversity. ATREE is involved in
the study of Inventory of Dung Beetles (scarabaeidae: coleoptera) and Ants (formicidae) of
Rajiv Gandhi National Park, (Nagarahole) Karnataka. This study was initiated during early 2001
with a financial assistance from Karnataka Forest Department as the project is nearing to
completion now, we have collected 96 species of dung beetles belonging o 12 genera and 60
species of ants belonging to 25 genera and this includes many new species and rarities
Some interesting ants of Rajiv Gandhi N.P. Nagarahole
Pachycondyla rufipes:
This ant is noted for its peculiar defense mechanism. If one tries to catch them, they squirt
out a spray of acidic venom from the tail end of the gaster, which gives a burning sensation,
or even cause a blister to the finger. This is premitive ant genus where a social hierarchy
controls reproduction. These colonies consist only of workers, which aggressively form a
dominance hierarchy in which, only the most dominant worker's offspring survive without
being eaten by other workers.
The jumping ants of India (Harpegnathos saltator):
These ants, which live in small colonies, are not so common but are plenty in Nagarhole.
They leap up to a meter or more in the air to catch flying insects with their long mandibles.
They escape from the enemies by jumping down from the substratum. These ants are considered
primitive because they form relatively small colonies, they have a relatively simple nest
structure and exhibit little or no worker specialization as in the other ant communities.
Nests of these ants contain only one or two queens. Queens look very similar to the workers
in morphology.
Genus and species Harpegnathos saltator do in fact exhibit monogyny and "Queens disperse by
flight and found colonies by themselves. Harpegnathos workers retain their ovaries and a
functional spermatheca, which enables them to mate and thus produce female offspring in case
of an emergency. After the queen's death some of the mated workers take over the colony and
reproduce and help the colony in surviving. Such workers are called gamergates.
Tetraponera rufonigra : an indicator for forest health?
Workers have acute vision and will dart to the far side of twigs or branches when approached.
During heavy rain, runoff water collects in the nesting holes of these ants. The Tetraponera
workers remove the water by ingesting it, walking to the entrance hole, and regurgitating it
to the outside. In this way, they reduce the danger of colony members drowning. These ants
nest in dry wood or on dead trees. They have a preference to feed on termites. So they
prefer to inhabit the forest area where there are plenty of dead trees. The relative high
abundance of these ants at certain parts of the National park is a cause of concern.
Some interesting Dung Beetles of Rajiv Gandhi N.P. Nagarahole
Onthophagus pactolus : A very rare Dung Beetle collected from Nagarahole
Heliocopris dominus: The largest Beetle in India. They breed only in elephant
dung. They show parental care and both partners care for the brood.
Onthophagus dama: One of the commonest Dung Beetle of Nagarahole.
Onthophagus sp. 81: A very common yet unidentified species of Dung Beetle collected
from Nagarahole.
Caccobious rufipenis: A cleptoparasitic Dung Beetle from Nagarahole.
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