**3.1 Species composition of** *An. gambiae* **complex and** *An. funestus* **group**

A total of 110 mosquitoes were identified to species level by PCR: 60 from Tiémélékro and 50 from Zatta. Within *Anopheles* spp. morphologically identified as *An. gambiae* complex, 100% were *An. gambiae s. s.* With regard to the *An. funestus* group, it consisted of 100% *An. funestus s. s.*

#### **3.2 Effects of agricultural practices (irrigated rice fields & vegetable farming) on**  *Plasmodium* **transmission**

Comparison between years revealed that the biting rate of *An. gambiae s.l*. in Zatta decreased several-fold from 49.3 bites per person per night (b/p/n) in 2002 to 7.9 b/p/n in 2003 (likelihood ratio test (LRT=1072.66; P<0.001). In Tiemelekro, the biting rates recorded in 2002 and 2003 remained fairly constant. These observations were paralleled by a marked decrease in the infective rate of *An. gambiae s.l*. in Zatta (4.6–1.2%), and an increase in Tiemelekro (3.1– 7.6%). Meanwhile, the entomological inoculation rate (EIR) of *An. gambiae s.l*. decreased 21 fold in Zatta, from 789 to 38 infective bites per person per year (ib/p/y), whereas it remained high in Tiemelekro (233 vs. 342 ib/p/y). In Zatta, the return to irrigated rice farming in January 2005 was paralleled by a significant increase of the EIR ranging from 38 infective bites per person per year (ib/p/y) in 2003 to 295 ib/p/y in 2005. In Tiémélékro high EIRs were found in 2003 (342 ib/p/y) and 2005 (572 ib/p/y).
