- Anopheles gambiae is one of the most medically significant mosquito species in the world and is widely recognized as the primary vector of Plasmodium falciparum, the parasite responsible for the deadliest form of malaria in sub-Saharan Africa.
- This species belongs to the Anopheles gambiae complex, a group of morphologically similar species that are often difficult to distinguish but vary in behavior and vector competence. Among them, An. gambiae sensu stricto is considered the most efficient and dangerous malaria vector due to its strong preference for human blood (anthropophily), high survival rates, and adaptation to domestic environments.
- Adult Anopheles gambiae mosquitoes are relatively small, slender, and dark, with long legs and narrow wings that feature distinctive pale and dark banding on the veins. They are most active during the nighttime, typically between dusk and dawn. Females are the blood-feeding sex and are highly anthropophilic, often entering homes at night to feed on sleeping humans. After obtaining a blood meal, the female mosquito lays her eggs in shallow, sunlit water bodies, such as puddles, rice fields, hoof prints, or temporary pools. The eggs hatch into aquatic larvae, which develop rapidly—often completing their life cycle in just 7–10 days under favorable conditions.
- The ecology and behavior of An. gambiae are closely linked to its role as a vector of malaria. Its preference for human hosts and indoor resting and feeding behaviors (endophagy and endophily) make it particularly susceptible to vector control measures such as insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS). These tools have significantly reduced malaria transmission in many parts of Africa. However, the species’ adaptability poses ongoing challenges. For example, An. gambiae populations have demonstrated behavioral plasticity, such as shifting to outdoor biting (exophagy) or feeding earlier in the evening to avoid contact with insecticides.
- Another major concern is the emergence of insecticide resistance in An. gambiae populations. Resistance to pyrethroids, the primary class of insecticides used in bed nets, is widespread across Africa. This resistance reduces the efficacy of standard vector control interventions and has prompted the development of next-generation insecticidal tools, including bed nets treated with combinations of chemicals or new classes of insecticides. Research is also focused on genetic control strategies, such as gene drive technologies, which aim to reduce mosquito fertility or render mosquitoes incapable of transmitting malaria parasites.
- The life cycle of malaria transmission involves the female An. gambiae acquiring Plasmodium parasites when feeding on an infected human. The parasites undergo development within the mosquito over approximately 10–14 days (the extrinsic incubation period) before migrating to the mosquito’s salivary glands. Upon the next blood meal, the infectious mosquito transmits the parasite to another person, perpetuating the transmission cycle. The efficiency with which An. gambiae completes this cycle is unmatched by most other mosquitoes, making it a keystone species in global malaria epidemiology.
- In addition to malaria, An. gambiae has been investigated for its potential to transmit other pathogens, such as filarial worms (causing lymphatic filariasis), although it is not considered a major vector of those diseases. Nevertheless, its dominance in malaria transmission continues to make it a central focus of entomological research, public health initiatives, and global disease control strategies.
