Why Mosquito Populations Persist During the Dry Season: An Explanation
The dry season is often perceived as a period when mosquito populations decline due to the reduction of stagnant water. However, drought conditions can actually create new habitats that support the breeding of certain mosquito species and increase the risk of disease transmission.
Changes in environmental conditions during the dry season cause water bodies to shrink. Reduced water flow leads to stagnant or still water, which serves as an ideal location for mosquitoes such as Culex pipiens to lay eggs. This phenomenon disproves the assumption that mosquitoes are only a threat during the rainy season.
Beyond natural factors, human behaviour during the dry season also contributes to the issue. A decrease in the supply of clean water encourages communities to collect and store water in various containers. If these storage vessels are not tightly sealed, they become breeding grounds for mosquitoes, including the Culex species, which can thrive in small pools of water around residential areas.
This condition must be monitored closely as various mosquito species carry serious disease risks. Based on data from the World Health Organization (WHO) and the CDC, several types of mosquitoes active during stagnant water conditions include those responsible for dengue transmission. In dengue cases, Aedes mosquitoes become infected after biting a person carrying the virus. The virus then develops within the mosquito’s body until it reaches the salivary glands, ready to be transmitted to another person during the next bite.
The public is urged to maintain the cleanliness of water storage areas and residual puddles even in the midst of the dry season. Vigilance regarding remaining stagnant water is crucial to breaking the mosquito breeding cycle and suppressing the risk of infectious disease spread.
The Health Office of Tasikmalaya Regency recorded 200 cases of DHF throughout January–July 2026, with one fatality reported during the dry season. Monthly case fluctuations were recorded as follows: 27 cases in January, 10 in February, 21 in March, 24 in April, 17 in May, 27 in June, 12 in July, and 18 in August, involving 88 males.
Up to the 30th week of this year, DHF recorded 122 cases and one death, whereas during the same period in 2025, cases reached 410 with three deaths. The activity of a weak La Niña phenomenon, coinciding with the rainy season in early 2026, is expected to increase rainfall in several regions of Indonesia. According to Ministry of Health data, throughout 2025, there were 161,752 recorded DHF cases resulting in 673 deaths.