Mosquitoes became the primary focus of discussion during the UPLB Museum of Natural History’s last Biodiversity Seminar by Majhalia M. Torno, a medical entomologist from the Research Institute for Tropical Medicine, Department of Science and Technology. The seminar was attended by almost 30 people, including delegates from the Texas A&M International University, at the MNH Conference Room on 06 July 2016.

“I would like my talk seminar to raise awareness, so that people would know that medical practitioners are also conducting studies on mosquitoes,” said Majhalia Torno as she talked on the significance of the topic and its importance to students. “Most of these topics are no longer tackled in classes anymore as the focus of entomology has been mostly on crop protection and not on these mosquitoes and their medical implications,” Torno added.

Torno mentioned that one of her organization’s aims is to develop among students and academics the interest in teaching medical entomology, which their department currently offers programs in. “It’s not that there are not any takers [of medical entomology], it is just that there is a lack of mentors,” Torno said.

In her presentation, she discussed several collection techniques used in the process of identifying mosquitoes. “Identification is the primary basis of control,” said Torno. “But there is a misconception that a single technique [in collecting mosquitoes] can be generally used for all types of mosquitoes when in fact there are various methods which are very specific to the species of vector.”

According to Torno, the Carabao-baited Trap (CBT) is the most effective method to catch mosquitoes. “The CBT is the most effective collection technique since it attracts and traps the most number of species of mosquitoes which can then be collected by manual aspiration using a sucking tube,” Torno confirmed.

She also mentioned other collection techniques such as the Monkey-Baited Trap (MBT), and the Human-Landing Catches (HLC). “The HLC is the most taxing technique as it requires humans to be exposed to mosquitoes. People who serve as bait should be awake the whole night,” she explains. In order to avoid bias during the collection, Torno states that the collectors and the human baits are put on rotation around at least 5 mosquito collection stations at different intervals. “This is also to reduce the length of exposure of the people to the mosquitoes,” Torno added.

The danger of exposing people just to collect mosquitoes has lead to the development of other safer techniques such as the Human Net-in-Net (HNN) method wherein a human is used as bait but a net separating them from the mosquitoes is used. Another method made is the Human Odor-baited E-net (HEN) where the natural odor released by the humans inside a tent is vacuumed out into trap which will attract the mosquitoes. “However, The HNN is not as effective as the other methods because it only attracts one or two species of mosquitoes with a very low amount,” Torno said.

Development of various mosquito collection techniques also brought the monkey odor-baited e-net (MEN) to come into light as well as the use of the Center for Disease Control Miniature Light Trap. Torno stated, “The CDC Light Trap is a method we now use for portable collection of mosquitoes and sand flies in very tight urban areas, however, like the HEN, the rate of collecting varying species of mosquitoes is also low.”

Mosquitoes have been known to be vectors of diseases such as dengue and malaria. Relaying some facts regarding these diseases, Torno shared “As compared to two decades ago, the rate of infection has significantly gone down. But last year, there was an estimated 7,000 cases of mosquito-caused diseases; compared to the previous year with only around 3,000 cases, which is very alarming”.

Torno then presented several graphs illustrating how these diseases are transmitted by mosquitoes over time; showing a relative increase in occurrence this year compared to the previous period. “It could be possible that the people are getting complacent with mosquitoes such that they do not use their vector controls anymore. It is also another possibility that the process of infection has changed from outdoors to indoors which is something we are constantly looking into,” Torno said.

The presentation thereafter lead to a discussion on susceptibility tests of vector controls that RITM is currently conducting. “We want to make sure the products people are using are efficient in the prevention of transmittal of such diseases. Our research show that in the National Capital Region at least 73% of the population of the Aedes aegypti mosquito is already showing resistance to commercially available insect-repellents.”

Torno also said that the RITM offers basic training to college students and government personnel, entomological investigations in response to an outbreak, and seminars to raise awareness on mosquitoes. At the end of her presentation, Torno answered a couple of questions from the attendees.

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