Confirming a prior report of this resistance profile in the central part of Zambia. This is a similar profile to that seen in Uganda and Kenya in East Africa. However, this species appears to be susceptible to both insecticides in the most southern part of its range in Mozambique. Carbamate resistance in this species is present in many parts of West Africa, but this is the most southerly that carbamate resistance has been reported in An. gambiae s.s. All populations were susceptible to organophosphates. However, potential resistance in An. gambiae s.s. to pirimiphos-methyl was detected in Copperbelt Province in 2013. This warrants further investigation with additional bioassays, as the country is likely to rely more heavily on organophosphates for vector control in the future. In addition, mortality rates to deltamethrin were higher in this area of the country, indicating relatively greater susceptibility to pyrethroids. Combined, this pattern of resistance in An. funestus s.s. may indicate that the mechanism underlying pyrethroid and carbamate resistance has recently spread to the western side of the country and is being selected for by extensive use of pyrethroids in IRS and LLINs. This conclusion is supported by the pattern of over expression of P450s involved in pyrethroid resistance in this area. Target-site resistance alone may not result in operational failure of vector control. However, in concert with metabolic resistance, it can be a major threat. In Benin, where pyrethroid resistance is conferred by both target-site and metabolic mechanisms, sleeping under an ITN in an area with a resistant population provides little protection against being bitten. DDT resistance appears to be emerging in An. funestus s.s. in the west and southern regions of Zambia. As target site resistance mechanisms have not been detected in An. funestus s.s., it is likely that this resistance has a metabolic basis. Interestingly, several CYP6Z and CYP6M genes are over expressed in these populations and paralogues of these gene have been shown to metabolise DDT in An. gambiae s.s. Further characterisation of these enzymes from An. funestus s.s. would be informative. Extremely high levels of malaria infectivity were detected in this study, which is in contrast to previous findings of low infectivity of An. funestus and An. gambiae in IRS and ITN areas. The vast majority of the specimens used in these assays were collected in April or May of 2012, which coincides with the end of the rainy season. This may contribute to the high levels of infectivity seen in this study. Although sporozoite data collected here was not designed to measure entomological inoculation rates, the values are high enough to suggest that control is not effective. This requires further investigation if the control programme is to maintain goals and reduce incidence of the disease in Zambia further.