‘Toxorhynchites’ mosquito species vs. malaria, dengue carriers
An elephant mosquito species called “Toxorhynchites,” which is undergoing entomology study in a Department of Health (DOH)-run insectary in Palawan, may hold promise against life-threatening mosquito-borne diseases, such as malaria and dengue fever. Also called the “mosquito eater,” the Toxorhynchites do not consume human blood but feed on other mosquito larvae during their juvenile form, entomologist Jessie Braganza Jr. of the Palawan Satellite Laboratory, Department of Entomology, Research Institute for Tropical Medicine (RITM) of the DOH said on Friday. Braganza, who is part of a health team that has been studying the Toxorhynchites since 2016, said their larvae consume those of other mosquitoes, making it beneficial to humans. He said they have tested feeding the Toxorhynchites with Aedes aegypti larvae, the mosquito responsible for spreading dengue, and the “results have been assuring so far.” “It’s a Toxorhynchites species. Actually, this mosquito we are studying has overlapping characteristics with Toxorhynchites splendens or another species. We have not tried feeding them with Anopheles mosquitoes that carry malaria,” he added. However, he said this will also be part of their study as they go along in helping find a solution against mosquito disease carriers. “Based sa study namin sa laboratory, totoong kinakain nila ang mga kiti-kiti ng ibang lamok. Kapag lumaki na sila ay enough na ang protein sa katawan nila kaya hindi na nila kinakain ang mga larvae ng iba. Hindi rin sila harmful sa humans,” Braganza also said. He noted that they tried rearing Anopheles mosquito larvae in the insectary to feed to the Toxorhynchites, but they have not been successful since their larvae appear to prefer the wilds to the laboratory breeding set up. “We started testing Aedis mosquitoes, especially in Puerto Princesa because of the advent of dengue. In Anopheles mosquito, we tried but they did not thrive in a laboratory set up,” he said. He added that they really had no plan to study the elephant mosquito species in the past. However, in one of their field assignments, they were able to collect Toxorhynchites. Braganza said they read about Toxorhynchites references in other countries and found out that its larvae also feed on other mosquito larvae. “Ang kagandahan sa lamok na ito, hindi siya nagfe-feed ng blood mula sa tao o sa ibang hayop. Kinakain niya ang kapwa niya larvae kasi kailangan niyang mag-consume ng protein papunta ng adult stage (What’s good about this mosquito is it does not feed on human blood. Its larvae feed on other mosquito larvae because they need to consume protein),” he said. Each larva of Toxorhynchites can feed on five to 10 larvae, according to their study. Braganza said their next trial will involve placing 500 Aedes aegypti larvae on a tray to see how fast the Toxorhynchites can consume them to the adult stage. DOH Assistant Secretary Maria Francia Laxamana said if study results are promising, especially against the dengue larvae, then it might be introduced later in some areas to fight the life-threatening disease.
“Ituloy niyo na ‘yan kasi baka promising nga. Kahit hindi na niya nakakain ang mga larvae kapag lumaki siya, imagine nalang kung lahat ‘yan kumain ng mga l arvae. Kahit papaano makakabawas pa rin. Dapat ipagpatuloy niyo ‘yan,” Laxamana said. DOH 4-B (Mimaropa) officerin-charge, Director Mario Baquilod, announced the entomology study of the elephant mosquito during the 8th ASEAN Dengue Day celebration in the province last June. He said then that the current RITM entomological research may have found a large larvae-eating mosquito that has the potential of destroying the immature dengue-carrying Aedes aegypti mosquitoes. (with reports from Aira Genesa Magdayao/PNA)