Discover How the Biological Clock of the Aedes aegypti Mosquito Works—the Vector of Dengue, Zika, and Chikungunya

The dengue mosquito does not behave the same way throughout the day. Aedes aegypti has an internal biological clock that regulates its periods of greatest activity, increasing the risk of bites at specific times, mainly early in the morning and late in the afternoon.

During these peak periods, the female mosquito becomes more sensitive to carbon dioxide (CO₂) released through human breathing. This gas acts as a signal that indicates the presence of a potential food source, primarily humans, and can be detected from more than 10 meters away. However, this sensitivity is not constant throughout the day; it fluctuates according to the insect’s natural biological cycle.

According to studies referenced by Superinteressante, this behavior is linked to a substance called Pigment‑Dispersing Factor (PDF), an essential component of the mosquito’s internal clock. PDF helps “switch on” the Aedes aegypti’s alertness at certain times, enabling it to respond to CO₂ for longer periods when it is naturally more active. Mosquitoes that do not produce this substance struggle to locate people, highlighting how critical this mechanism is in shaping the mosquito’s behavior.

Understanding how the mosquito responds to stimuli throughout the day is an important step toward improving surveillance and control strategies. By learning more about its biological cycles, we can design more targeted and effective approaches to prevent dengue transmission.

At Aedes Mosquito Killers, we believe that science‑based information is an essential part of the ongoing effort to address this public health challenge.