Anna Santiago

Larval mosquito collection was performed in Barangay Binubusan, Lian Municipality, Batangas Province during the last quarter of 2008 from October to December to determine the mosquito populations present in the area. Mosquito larvae were collected from various habitats, namely: rice paddy, sunny pond, open residential canal, shaded pond, and abandoned tire. A dichotomous key was devised for the identification of local mosquito fauna. A total of 1,128 mosquito larvae were collected during the study period, comprising 958 (84.93%) Culex, 125 (11.08%) Aedes, and 45 (3.99%) Anopheles. The highest larval collection was recorded in November consisting of 100% Culex spp. Five Culex species were identified: Culex quinquefasciatus (51.86%), Culex vishnui (14.0%), Culex tritaeniorhynchus (9.84%), Culex whitmorei (8.78%) and the first reported presence of Culex mimeticus (0.53%) in the country. Aedes species were represented by Aedes vexans (5.94%), Aedes aegypti (4.34%), and Aedes niveus (0.80%). Anopheline mosquitoes were represented only by Anopheles flavoristris (3.99%). Of the species identified, only Ae. aegypti and An. flavirostris have been documented of public health importance in the country.

THE OCCURRENCE of unpredictable extreme weather events and the increase in global average temperatures have made climate change an unequivocal crisis. Although climate change is influenced by natural phenomena such as the periodic variation in the Earth’s orbit around the sun, the changes the world is experiencing today are attributed to man-made global warming.

The relative indoor density of Aedes sp. was determined through ovitraps installed in a cluster of 10 households in Barangay Sta. Cruz, Makati City. The house of a dengue case served as the index household from which 9 households located within a 300-meter radius were randomly selected. Each sample household was provided an indoor ovitrap that was installed in a low, dark and protected corner of the house. Ovitraps were collected and subsequently installed every Monday and Thursday so that each sample household had an ovitrap installed throughout the duration of the study. A total of 50 ovitraps were collected and examined for the presence of Aedes sp. larvae. Lawanit paddles from the ovitraps were reared in the laboratory and the number of larvae were counted and recorded. Ovitrap surveillance resulted to a mean larvitrap index of 5.32 larvae/ovitrap with a standard deviation of 5.30 and a mean house index of 40% for the period of January 17, 2005 to February 3, 2005.

Surveillance of the presence of larval mosquitoes was performed in the suburban municipality of Sta. Ignacia,Tarlac Province, Philippines, with approximately 94.0% of the land area still devoted to agriculture. Fivedistricts were covered, namely: Macageuing, San Francisco, San Vicente, Sta. Ines Centro, and Sta. Ines East. The standard dipping method was used to collect mosquito larvae from rice fields, ponds, creeks, streamsand used tires and larvae were identified at the genus level. Culex sp. was the most abundant with acalculated mean breeding index of 22 larvae per dip. Anopheles sp. and Aedes sp. were likewise identifiedwith mean breeding indices of five and two larvae per dip, respectively. In two samplings, Culex sp. had thehighest mean larval breeding index (MLBI) of 9 larvae/dip in Sta. Ines Centro (West); while Sta. Vicenteregistered higher MLBI of Anopheles sp. and Aedes sp. relative to sites in other districts. Considering theendemicity of malaria, lymphatic filariasis and dengue in the country, present findings are valuable in theformulation of control measures specifically targeting presently identified breeding sites that revealedconsiderable mosquito population. To arrive at a comprehensive picture, we highly recommend a validationof current data in similar sampling sites in the other districts of Sta. Ignacia, concurrent with a species-specific surveillance of culicidae mosquitoes.