STUDIES ON POPULATIONS AND FEEDING HABITS OF TRINSRVITERMSS GEHINATUS (WASMANN), (ISOFTERA) AND ITS SIGNIFICANCE IN PASTURES IN THE SOUTHERN GUINEA SAVANNA ZONE OF NIGERIA
STUDIES ON POPULATIONS AND FEEDING HABITS OF TRINSRVITERMSS GEHINATUS (WASMANN), (ISOFTERA) AND ITS SIGNIFICANCE IN PASTURES IN THE SOUTHERN GUINEA SAVANNA ZONE OF NIGERIA
No Thumbnail Available
Date
1976-11
Authors
CLIFFORD, EZEKWESIRI OHIAGU
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The main objective of this study was to assess the damage to grazed
pastures in the Mokwa area of the Southern Guinea savanna zone of Nigeria
by Trinervitermes geminatus (Wasmann) (Isoptera, Termitidae, Nasutitermitinae)
and to determine its role as a competitor with grazing livestock. In
Nigeria, T. geminatus is the only species which cuts down standing grass
and at the same time is sufficiently abundant to be considered a potential
threat.
T. geminatus builds domed-shaped mounds which are highly aggregated
and serve as breeding and storage sites. Some of these mounds are subsequently
abandoned and are either eroded away or are reoccupied by the nonmound
building species of the same genus or other termites notably Cubitermes
sp., Promirotermes sp. and Microtermes spp. During the rainy
season, new mounds are constructed and old mounds are enlarged.
Population density of T. geminatus was estimated in grazed and
ungrazed areas of a secondary woodland, as well as in a primary savanna
woodland. Populations were low (203/m ; 232 mounds/ha) in the areas of
study and seasonal fluctuations in them were indicated. Decrease in population
during the dry season, coincided with the period of active foraging
and intense predation, and they increased during the rains. Following the
flight of alates in July/August, populations again declined.
The foraging habits of T. geminatus and the quantity of grass removed
were investigated. Foraging in the Mokwa area was in early morning or late
afternoon and lasted about 2-3 hours. It was greatly influenced by
environmental factors such as rain, soil surface temperatures and relative
humidity. Grass production was estimated at approximately 3000 kg/ha/annum,
and of this quantity cattle consumed approximately half the annual production 48%).
A method was developed for quantifying the amount of grass harvested
by T. geminatus, and following this method, the quantity of grass removed
by this species was estimated as representing 3.5% of the total annual
grass production. Therefore, the quantity of grass removed and hence made
unavailable for cattle consumption was insignificant in this locality.
Although, field and laboratory investigations on the choice of grass
indicated a strong preference by T. geminatus for Andropogon gayanus, a
grass species equally preferred by cattle, they hardly competed for it in
the Mokwa area. It is however suggested that the impact of grass harvesting
by T. geminatus would be relatively greater in areas with high populations
of termites and in overgrazed pastures especially during periods of drought
when grass production is lowered by poor management or low rainfall
Description
Dissertation submitted for the degree of Ph.D
Ahmadu Bello University
Zaria
Nigeria November, 1976
Keywords
FEEDING HABITS,, TRINSRVITERMSS GEHINATUS,, (WASMANN),, (ISOFTERA),, SIGNIFICANCE,, PASTURES,, SOUTHERN GUINEA,, SAVANNA ZONE OF NIGERIA