Abstract
M.Sc.
Members of the Suborder Microchiroptera consume large numbers of insects. When
large enough numbers of these bats are present in agricultural areas, the need for
insecticides can be reduced significantly. The ZZ2 Tomato Farms in Mooketsi and
the Secrabje Farm in Waterpoort, in the Limpopo Province were chosen as study
sites. Although ZZ2 focuses on the production of tomatoes, both farms produce a
variety of vegetables and fruit. These farms were chosen because the management
of both have shown a commitment to conservation and attempt to minimise their
impact on the environment. Bat species indigenous to the study areas were captured
by means of mist nets for identification purposes. Basic morphological data of
captured specimens were collected and recorded. Their roosting behaviour and
preferences were studied by visiting diurnal roosts in the two study sites.
Microclimatic measurements were taken in roosts occupied by Chaerephon pumilus,
Mops condylurus and Taedarida aegyptiaca. Microclimatic measurements were also
done in bat houses designed for the housing of bats in agricultural areas. Results
suggest that other factors, additional to temperature and relative humidity, contribute
to the success and probability of bat house occupancy by bats. Existing roosts in
man-made structures such as roofs, can successfully be enhanced to stimulate
increase in colony size. Bat activities were determined in agricultural areas and
adjacent natural habitats by means of recordings of the echolocation calls of the
different bat Families. These were compared to the occurrence of nocturnal flying
insect orders that were captured in light traps at the same localities. Of the bat
species studied, a positive correlation between increased bat activity and higher
number of insects, including pest species, was found. It seems as if the Molossidae
has the greatest potential to be utilised in the control of insect pests of agricultural
areas in the Limpopo of the bat species studied. A holistic approach favouring
insectivorous bats on farms is recommended. This can be done i.a. through the
conservation of abundant areas of natural vegetation adjacent to the agricultural
areas which would provide foraging for bats during winter, periods of drought or
when the lands lie fallow. The excessive and injudicious use of insecticides, which
has a negative effect on bats, counteracts the beneficial and cheap alternative of
natural insect pest control provided by insectivorous bats.