Table 1.

Immature mosquito densities before and after O. niloticus introduction into ponds C and D

	Pond Aa		Pond C			Pond D
Mosquito species	Beforeb	Afterc	Before	After	% Reductiond	Before	After	% Reduction
A. gambiae s.l.	4.50 ± 0.56	14.08 ± 0.93	11.38 ± 0.67	1.53 ± 0.28	95.8	5.40 ± 0.34	1.00 ± 0.15	94.1
A. funestus	0.06 ± 0.04	2.45 ± 0.47	0.57 ± 0.1	0.43 ± 0.14	98.3	0.61 ± 0.14	0.56 ± 0.10	97.5
Culicines	2.34 ± 0.38	4.51 ± 0.44	2.81 ± 0.47	0.72 ± 0.18	86.7	1.29 ± 0.21	0.63 ± 0.13	75.4

^a Pond A was the control pond, ponds C and D were treated

^b 'Before' refers to the 15 weeks before fish introduction into ponds C and D

^c 'After' refers to the 15 weeks after fish introduction into ponds C and D

^d Percentage reduction was corrected for observed natural increases in the control pond using Mulla's formula [19].