DISCUSSION AND CONCLUSIONS
Methanol extracts and plant powders performed better in
the laboratory than in the artificial ponds under semi-field
conditions. This may have been due to relatively high afternoon
temperatures in the screen house and/or due to exposure of the
active constituents to microbial populations in artificial ponds,
which may have affected their biodegradation. Interestingly, the
two plant powders performed better than methanol extracts in
screen house experiments. More detailed time-course comparison
of constituents of aqueous substrates associated with powder
suspensions and solvent extracts may help to throw some light on
this difference. From a practical perspective, pulverized root and
stem barks of K. uguenensis constitute a safe and more readily
accessible material for mosquito larval control by rural
communities.