Increasing evidence of a change in biting and resting behaviour of the main malaria vectors has been mounting up in recent years as a result of selective pressure by the widespread and long-term use of LLINs and IRS [13,14,15]. Mosquito behaviour is quite variable, with changes in mosquito behaviour posing great challenges to malaria elimination efforts [16, 17]. Residual malaria is also influencing malaria burden in low transmission areas .
Anecdotal evidence from Limpopo Province in South Africa shows that the increase in cases may be attributed to the sub-optimal vector control . Since adult control methods have been proven to be insufficient to control the disease, larval source management and especially larviciding is increasingly being recommended as an additional strategy in integrated vector control programmes mainly in elimination settings . Mosquito behaviour is quite diverse with distinct preferences in terms of when egg oviposition and adult emergence from the pupal stage occurs [20,21]. It was shown that there are definite periods during the night when oviposition is favoured. Adult emergence from the pupal cases also occurs at a preferred time in early evening just after sunset. It was demonstrated that female mosquitoes can take a blood meal soon after emergence as well as immediately after egg-laying. Newly emerged mosquitoes took a bloodmeal in the laboratory where conditions were carefully controlled and this behaviour would need to be corroborated by field studies. In virgin females, a blood meal is essential for the development of metabolic reserves prior to mating . Proportionally 25–30% more females are produced which may be due to differential mortality of males and females since climatic variables influence the lifespan of the sexes . Masters  also recorded that most mosquitoes emerged in the early hours of the evening. Newly emerged males are not equipped to mate until genital reorient is complete  and An. arabiensis optimal mating occurs with 5–7-day-old males . Since males only swarm for mating purposes, virgin females will enter the swarm only when they are ready to mate.
In order to target the aquatic stages of the mosquito life cycle, a comprehensive knowledge of the larval bionomics is essential. An understanding of mosquito oviposition behavior is necessary for the development of surveillance and control opportunities directed against specific disease vectors . In this study, vector oviposition and emergence coincide with the bedtime of people living in rural areas as Pates and Curtis  found and that the traditional vector control interventions are ineffective as a result of this human behavior. Most people in rural areas go to bed just after sunset (between 20h00 and 22h00) and get up just before sunrise (between 04h00 and 05h00). With vector females laying eggs during these times and with the emergence of many females, there are a large number of vectors that are able to take a blood meal. According to the study by Milali et al  this coincides with the peak biting times of Anopheles arabiensis of 21h00 -22h00 and 03h00-04h00.
Approximately 75% of all eggs laid produce viable first instar larvae and this is in keeping with the observations of the same mosquito populations made by Maharaj . This study complements the study of adult life table characteristics detailed by Maharaj [8,26]. Impoinvil et al  found that mosquito eggs held at 22 and 27°C had the highest overall mean hatching count. The temperature at which the eggs in this study was maintained fell within this range so the egg hatch rate was at its optimal. The sex ratio of the emerging mosquitoes from the Mamfene population reared under ideal conditions showed a clear female bias. This has implications for the sterile insect technique (SIT) studies planned by the control programmes for this area in KwaZulu-Natal. The population structure of these mosquitoes will require further study before such a programme can be implemented. It will require a sex distortion which is male biased for SIT to succeed .
The results of this study can help in streamlining vector control interventions targeting malaria elimination. When temperatures are high and the development of mosquitoes is rapid , larviciding can become a costly and labour intensive exercise since the breeding sites are many during summer and the generation time is short [8,26]. The study has shown that the egg hatch rates are quite high under optimum conditions, and therefore the use of larval control measures would prevent the rapid build-up of the populations under optimum environmental conditions. There are many proponents for winter larviciding  which is the application of chemicals to the breeding sites found during the dry winter season since vectors are in hibernation as larvae and are vulnerable to larval control measures. Previous studies have shown that winter larviciding delays the onset of transmission since the mosquito populations emerging from winter hibernation is low [7,26] and hibernating females have undergone gonotrophic dissociation .
This study has shown that inseminated females that have just oviposited are able to take a blood meal. Immediately upon emergence, both the males and females need to replenish their energy, the males for swarming and the females for mating and host detection. If females emerging from known breeding sites were to feed on toxic baits or insecticide treated animals, strategically placed around the geo-located active breeding sites, the population available for blood feeding and transmission would be lowered . However, as this study has shown, newly emerged females as well as those having just oviposited can, under specific laboratory conditions, also take a blood meal without the benefit of a sugar supplement. Since the females feed opportunistically, livestock treated with endectocides, and placed strategically close to geo-located permanent mosquito breeding sites, could be used divert females from feeding on humans . The study also supports the recommendation from investigations into the use of the sterile insect technique (SIT) that more sterile males be introduced into an area to outcompete non-sterile males . This study has demonstrated that even under optimum conditions fewer males than females are produced and hence the release of large numbers of sterile males would be successful in reducing competition from wild, unsterilized males . Furthermore, male control can be achieved by baits and swarm space spraying  However, according to Maharaj , there is a slight variation in sex ratio across seasons requiring that prior to the implementation of a SIT program, constant monitoring of the wild male population to adjust the release rate over time may be required.
This study adds to the sparse body of literature available on vector bionomics in South African mosquito populations but is limited by the laboratory conditions under which the study was conducted. Certain aspects would need to be evaluated under field conditions, especially the time to blood-feeding by newly emerged females. Nevertheless, the study has provided data on oviposition, egg hatch rates, sex ratios and adult emergence. The value of baited traps, space spraying and animal barriers need to be investigated in their own right under field conditions in low transmission settings such as KwaZulu-Natal.