31/07/2026
For decades, Filipinos have been told that the mosquitoes carrying dengue bite during the day.
That advice still holds trueโbut it is no longer the whole story.
Researchers from the University of the Philippines Los Baรฑos (UPLB) have found that dengue transmission in the country has effectively become a 24-hour threat due to the growing role of a second mosquito species, Aedes albopictus, which remains active well into the evening and nighttime.
Unlike the better-known Aedes aegypti, the primary dengue vector that feeds mainly during daylight hours, Aedes albopictus bites from late afternoon through the night. The findings came from entomological studies conducted by Dr. Pio Javier and Dr. Barbara L. Caoili of the UPLB Institute of W**d Science, Entomology and Plant Pathology.
The researchers also documented a major behavioral shift in the species.
Previously regarded as a forest and rural mosquito that mostly fed on animals, Aedes albopictus has increasingly adapted to urban environments. It is now commonly found around homes and neighborhoods, breeding in clean, stagnant water collected in flowerpot saucers, discarded tires, roof gutters, buckets, and other household containers.
The shift means dengue prevention can no longer focus only on daytime exposure.
According to the researchers, many people stop using mosquito repellents or other protective measures after sunset because they believe the danger has passed. But the night-biting mosquito takes advantage of that false sense of security, making evening and nighttime another window for dengue transmission.
Scientists believe rapid urbanization, the loss of green spaces, and the abundance of artificial breeding sites have helped drive the mosquitoโs expansion into cities. Artificial lighting may also be extending the insectโs active hours by disrupting its natural biological rhythms.
The findings reinforce the need for year-round and round-the-clock dengue prevention.
Health experts continue to urge the public to eliminate stagnant water every week, install window and door screens, and use mosquito repellents not only during the day but also in the evening, particularly in semi-open areas such as porches, garages, and gardens.
For many Filipinos, dengue has long been considered a daytime danger.
UPLBโs research suggests that assumption may no longer be enough to keep families safe.
(โ๏ธ:Top Dagohoy)
