{"id":17423,"date":"2016-02-03T00:00:43","date_gmt":"2016-02-03T04:00:43","guid":{"rendered":"http:\/\/beyondpesticides.org\/dailynewsblog\/?p=17423"},"modified":"2016-02-03T10:22:17","modified_gmt":"2016-02-03T14:22:17","slug":"with-zika-virus-widespread-pesticide-spraying-not-the-long-term-solution-says-entomologist","status":"publish","type":"post","link":"https:\/\/beyondpesticides.org\/dailynewsblog\/2016\/02\/with-zika-virus-widespread-pesticide-spraying-not-the-long-term-solution-says-entomologist\/","title":{"rendered":"With Zika Virus, Widespread Pesticide Spraying Not the Long-Term Solution, says Entomologist"},"content":{"rendered":"

(Beyond Pesticides, February 3, 2016) Speaking to The Guardian<\/em>, a leading Kenyan entomologist warns that spraying pesticides will fail to deal with the Zika virus. Just recently the World Health Organization (WHO) declared the virus a public health emergency over growing concerns that the virus is linked with microcephaly. Aerial and ground applications of pesticides have long been used for mosquito control, but many believe that these methods fail to sufficiently control mosquito populations, promote resistance and kill other species that would have acted as a natural predator to mosquitoes.<\/p>\n

\"Aedes_aegypti_feeding\"Dino Martins, PhD, a Kenyan entomologist in an interview with The Guardian<\/em> said that while pesticides can reduce the population of \u00a0flying adult mosquitoes that transmit the virus, they will fail to deal with the epidemic that threatens to become a global pandemic, and warns that spraying landscapes is extremely dangerous. \u00a0\u201cIt is a quick fix but you pay for it. You kill other species that would have predated on the mosquitoes. You also create a mosaic of sprayed and unsprayed low densities of chemicals that fosters the rapid evolution of resistance.\u201d<\/p>\n

Mosquitoes have very short life cycle (a week or less), increasing the probability that each succeeding generation is an opportunity for random mutations to occur that predispose a group of mosquitoes to be immune to pesticides. \u201c[W]hen you use chemicals, you are actually applying a selection pressure on mosquito populations that will drive them to become resistant,\u201d says Dr. Martins. Already there is emerging resistance to insecticides<\/a> among \u00a0Anopheles<\/em> \u00a0mosquitoes. Additionally it is impossible to fumigate every corner of habitat where mosquitoes might breed.<\/p>\n

Zika virus is transmitted by the Aedes<\/em> \u00a0mosquito and has been linked to cases of microcephaly, in which babies are born with underdeveloped brains. The virus has been detected in several Latin American countries, including Brazil where the outbreak was first observed and linked to increased cases of microcephaly. According to Dr. Martins, the explosion of mosquitoes in urban areas, which is driving the Zika crisis, is caused by a lack of natural diversity that would otherwise keep mosquito populations under control, and the proliferation of waste and lack of disposal in some areas which provide artificial habitat for breeding mosquitoes.<\/p>\n

Dr. Martins, who runs the Mpala Research Centre, a field station affiliated with Princeton, Smithsonian Institution, Kenya Wildlife Service and National Museums of Kenya, says, \u201cWe are basically fighting an arms race with mosquitoes rather than cleverly understanding its life cycle and solving the problem there. Resistance can never evolve to getting rid of the breeding sites. But resistance will always evolve to the use of pesticides.\u201d<\/p>\n

Dr. Martins believes that attention must be paid to eradicating mosquitoes at the larval stage of their life cycle. \u201cIt might seem easier to just to spray but pesticides will not work long term,\u201d he says. \u201cWe need to ask \u2014 what is the weakest point in the life cycle of this vector? For me, it is the larvae because they are fixed and findable. You can destroy them right there. Once the mosquitoes fly, it is far harder … We need more investment in mosquito control at early rather than late stages.\u201d<\/p>\n

Whether its Zika, Chikungunya, or West Nile virus, combating mosquito-borne infections should include good surveillance and scientific understanding for controlling mosquito populations. A large part of this, as Dr. Martins noted, has to do with understanding the life cycle of mosquitoes and their biology. Another large part of this has to do with the inability, especially in an urban environment, to hit target insects with typical ground spraying from trucks or by aerial application. The efficacy of adulticidal pesticide applications (aerial or ground spraying) has been called into question over the years. Usually, this is the least efficient mosquito control technique that only targets adult mosquitoes. Further, the drifting spray impacts other non-target organisms like pollinators<\/a>, birds, fish and amphibians. Commonly used mosquito pesticides like permethrin<\/a>, resmethrin<\/a>, naled<\/a> and malation<\/a> are all associated with some measure of human and ecological health risks, especially among people with compromised immune systems, chemically sensitized people, pregnant women, and children with respiratory problems, such as asthma.<\/p>\n

Most experts agree that an efficient mosquito management strategy emphasizes public awareness, prevention, and monitoring methods. However, if these methods are not used properly, in time, or are ineffective, communities must decide whether or not to use pesticides. They must determine if they should risk exposing vulnerable populations to potentially harmful diseases caused by mosquitoes or to chronic or deadly illnesses caused by pesticides.<\/p>\n

What you can do?<\/strong><\/p>\n

Beyond Pesticides says \u00a0the ideal \u00a0mosquito management strategy<\/strong><\/a> \u00a0comes from an integrated approach that emphasizes education, aggressive removal of standing water sources, larval control, monitoring, and surveillance for both mosquito-borne illness and pesticide-related illness. Control of disease-carrying mosquitoes can be successful when emphasis is placed on public education and preventive strategies.<\/p>\n

Individuals can take action by eliminating standing water, introducing mosquito-eating fish, encouraging predators, such as bats, birds, dragonflies and frogs, and using least-toxic larvacides like \u00a0bacillus thuringiensis israelensis<\/em> \u00a0(Bti). Community based programs should encourage residents to employ these effective techniques, focus on eliminating breeding sites on public lands, and promote monitoring and action levels in order to determine what, where, and when control measures might be needed. Through education of proper cultural controls, and least-toxic and cost effective biological alternatives, the use of hazardous \u00a0control methods, such as toxic pesticides, can be eliminated.<\/p>\n