30
Nov
(Beyond Pesticides, November 30, 2023) Scientists at Minami Kyushu University in Japan have made a groundbreaking discovery of a new biological control for a target insect. They have identified a virus in tobacco cutworms that kills males, creating all-female generations. The discovery was described in a recent issue of the Proceedings of the National Academies of Sciences and The New York Times as evidence that multiple viruses have evolved to kill male insects. This “male-killing” virus could be added to the growing attempts to control unwanted insects with biological, as distinguished from genetically engineered (GE) solutions. Efforts range from the introduction of natural predators, to radiation-based sterilization of insects, CRISPR-based genetic mutations, and other techniques. While the GE approach has run into controversy because of unanswered questions associated with their release into natural ecosystems, some approaches have also run into resistance problems. Nearly a decade ago, researchers found armyworm resistance to Bacillus thuringiensis (Bt)-incorporated genetically engineered (GE) maize in the southeastern region of the U.S., calling this evolution of insect resistance to a naturally occurring soil bacterium engineered into crops “a serious threat to the sustainability of this technology.” The general population knows to avoid eating raw eggs because the bacteria salmonella, […]
Posted in Agriculture, Alternatives/Organics, Biological Control, Climate Change, Ecosystem Services, Malaria, Mosquitoes, Pesticide Efficacy, Pests, Uncategorized | No Comments »
10
Oct
(Beyond Pesticides, October 10, 2023) In recent years, the effects of climate change have become more frequent and more severe, from extreme weather events to rising sea levels. But perhaps one of the most insidious consequences of a warming planet is the way it influences the spread of diseases, often hitting marginalized communities the hardest. This is no more evident than in the case of malaria, where the disease transmission through the Anopheles stephensi mosquito serves as a dire warning of the challenges caused by a changing climate. As this deadly vector of disease expands its territory, it is clear that pesticide-intensive approaches are poorly equipped to cope with the threat as insect resistance to chemical controls steadily grows. Native to South Asia, the Anopheles stephensi mosquito has been on a relentless journey, crossing continents from the Arabian Peninsula to East Africa and deeper into the African continent. The mosquito’s ability to quickly adapt to new environments, bolstered by shifting climate patterns, illustrates how global warming affects disease vectors. Matthew Thomas, PhD, emphasizes, “Anopheles stephensi has higher thermal tolerance and a capacity to transmit at higher temperatures than Anopheles gambiae [another malaria-spreading mosquito]. This is significant when considering climate change […]
Posted in Malaria, Mosquitoes, pyrethroids, Synthetic Pyrethroids, Uncategorized | No Comments »
02
Aug
(Beyond Pesticides, August 2, 2023) A study published in Pest Management Science finds resistance to insecticides like pyrethroids are challenging attempts to control the mosquito Aedes aegypti (Ae. aegypti), the primary transmitter (vector) of dengue fever. While this study takes place in Bangladesh, resistance to biocides—whether to antibiotics, antimicrobials, or pesticides—is growing globally. Prevention of disease outbreaks is threatened by reliance on chemical biocides to which pathogens and their vectors develop resistance. In fact, resistance is predicted by elementary population genetics, and the speed of its evolution is directly related to the toxicity—that is, the strength of selection pressure—and inversely related to the generation length of the organism. (See PAY articles here and here, a PBS article here.) Insecticide resistance has been an issue since the introduction of DDT (dichlorodiphenyltrichloroethane) in the 1940s. Although most countries currently ban DDT use, the compound is not the only chemical pesticide promoting pest resistance. Several current-use insecticides pose the same threat. Areawide, indiscriminate spraying of insecticides is causing resistance to develop among many pests. Mosquitoes have become increasingly resistant to synthetic pyrethroids, in addition to other classes of insecticides, such as carbamates and organophosphates. Thus, this study demonstrates the need for sustainable and practical strategies […]
Posted in Infectious Disease, Malaria, Mosquitoes, Resistance | 1 Comment »
08
Jul
(Beyond Pesticides, July 8, 2020) Efforts to control the transmission of malaria are encountering a big, though predictable, problem: the mosquitoes that transmit malaria are developing resistance to at least five of the insecticides that have been central to limiting transmission of the disease. A study released in late June reveals a dramatic increase in resistance to pyrethroid insecticides and DDT across sub-Saharan Africa. This signals the failure of a mainstay chemical approach to the spread of malarial mosquitoes; this same problem — resistance — is happening with chemical management of agricultural pests and weeds, and with antibiotics to treat human bacterial infections. This study underscores a point Beyond Pesticides has made repeatedly: resistance to pesticides (whether insecticides, herbicides, biocides, fungicides, or medical antibiotics) is nearly inevitable. The solution to containing the spread of malaria lies not in the use of more and different chemicals, but in nontoxic approaches that respect nature and ecological balance. Malaria is a sometimes deadly disease caused by female Anopheles mosquitoes infected with any of four varieties of the Plasmodium parasite. The disease kills roughly 400,000 people annually, with half that mortality in sub-Saharan Africa. The U.S. sees approximately 2,000 cases of malaria annually, primarily in […]
Posted in DDT, Deltamethrin, International, Malaria, Mosquitoes, Resistance, Synthetic Pyrethroid, Synthetic Pyrethroids, Uncategorized, World Health Organization | No Comments »
31
May
(Beyond Pesticides, May 31, 2018) Deforestation in tropical regions helps spread malaria, concludes a recent research study of the Amazon Rainforest. Published in Nature’s open-access journal, Scientific Reports, the study details researchers’ work, from 2009–2015, comparing patterns of deforestation to rates of malaria in nine states in the Brazilian rainforest. Investigators found that the highest malaria incidence concentrated in impacted patches of forest — areas deforested or otherwise degraded from an unmanaged or more-natural state. These medium-sized patches (from .1 to 5 sq. km. in size) seem to be the “sweet spots” at which wood extraction activity (logging, charcoal production, et al.) correlate most strongly with malarial infection rates. The researchers suggest that the finding is perhaps related to the habitat preferences of the primary malaria vector in the region, Anopheles (Nyssorhynchus) darlingi, which breed most happily in shady, watery, edges of forest habitat. Sixty of the 380 mosquitoes in the genus Anopheles can transmit the malaria parasites. Deforestation fragments the forest landscape, creating more forest “edges,” which means more places for mosquitoes to breed. This fragmentation may also help malaria-carrying mosquitoes spread to other areas as adults: “The new [fragmented] landscape delineated by the pattern of deforestation and soil occupation may favor […]
Posted in DDT, Malaria, Mosquitoes, Uncategorized | No Comments »
22
May
(Beyond Pesticides, May 22, 2012) The Spanish-based Inesfly company announced recently its plans to release commercially pesticide encapsulated paint, Inesfly 5A IGR, containing two neurotoxic organophosphates (OPs), chlorpyrifos and diazinon, and the insect growth regulator (IGR), pyriproxyfen, which it hopes will combat malaria in sub-Saharan Africa. The company’s owner Pilar Mateo, PhD, calls her product “a vaccine for houses and buildings” and explains that because the insecticides are released slowly from the paint, it remains effective for two to four years. This formulation of Dr. Mateo’s paint could not be registered for use in the U.S. because both indoor residential uses of chlorpyrifos and diazinon have been banned because of risks posed to children’s health, although the company has another formulation that substitutes pyrethroids for the organophosphates. Though probably well-intentioned —Dr. Mateo has already invested $6 million of her family’s money and $12 million in grants from nonprofits, on research, creating educational programs about hygiene, and donating paint to more than 8,000 homes in Latin America and Africa””the product puts the people it is supposed to protect from disease at risk for other health problems. Organophosphate insecticides have been linked to a host of neurodevelopmental problems, especially in children. Because […]
Posted in Chlorpyrifos, Diazinon, Disease/Health Effects, Malaria, Mosquitoes | No Comments »
17
May
(Beyond Pesticides, May 17, 2012) Rather than investing in safe, long-term solutions to prevent malaria mortality, the World Health Organization (WHO) has issued a strategic plan that calls for multiple toxic pesticides to combat mosquito resistance to insecticides that is showing up in sub-Saharan Africa. Insecticide resistance, according to the WHO report, is already rampant in 64 malaria-ridden countries and may result in as many as 26 million more cases of malaria a year, which could end up costing between $30 and $60 million annually for tests and medication. Mosquitoes in sub-Saharan African countries are becoming resistant to pyrethroid insecticides, which are used extensively for household spraying and treating bed nets, as well as to the organochloride compound DDT -which is still used in many parts of the world to control mosquitoes. In Somalia, Sudan and Turkey, resistance has spread to carbamates and organophosphates in addition to pyrethroids and organochloride pesticides. Rather than reducing the reliance on these products, WHO is recommending rotating classes of pesticides used to spray inside homes and developing a new non-pyrethroid insecticide to treat bed nets. Implementation for these suggestions are estimated to cost around $200 million, which is in addition to the $6 billion […]
Posted in International, Malaria | No Comments »
01
Mar
(Beyond Pesticides, March 1, 2011) As insect resistance to pesticides steadily increases, and the underlying conditions of poverty, poor water management, and indecent living conditions contribute to the spread of malaria, the search for silver bullet solutions escalates. Researchers are exploring genetic engineering as the next frontier for a product-based approach to fighting malaria, which annually kills nearly one million people worldwide. While releasing genetically engineered organisms into the environment raises serious concerns that must be fully studied, some in the public health community believe this could help slow the spread of malaria as part of an integrated campaign. At the same time, the long-term underlying causes that support the spread of malaria must be addressed. The new research indicates that a genetically engineered fungus carrying genes for a human anti-malarial antibody or a scorpion anti-malarial toxin could be an effective tool for combating malaria, at a time when the effectiveness of current pesticides against malaria mosquitoes is declining. The researchers also say that this general approach could be used for controlling other devastating insect and tick bug-borne diseases, such as or dengue fever and Lyme disease. “Though applied here to combat malaria, our transgenic fungal approach is a very […]
Posted in Alternatives/Organics, Disease/Health Effects, Genetic Engineering, Malaria | No Comments »
16
Apr
(Beyond Pesticides, April 16, 2010) Every day, children still die of malaria, a devastating disease that is both preventable and curable. In 2009, the United Nations Environment Program (UNEP) and the World Health Organization (WHO) announced a renewed international effort to combat malaria with an incremental reduction of the reliance on the synthetic pesticide DDT. However, efforts to invest in real solutions are often derailed by those promoting DDT as a “silver bullet” for malaria prevention. Tell President Obama that the President’s Malaria Initiative must invest in safe solutions to malaria, not increase reliance on DDT. Sign by April 22nd and you will be included in the petition to mark World Malaria Day. Sign the petition here. DDT, or dichloro diphenyl trichloroethane, while highly persistent in the environment, was initially found to be effective against mosquitoes and the diseases they carry, such as malaria. However, insect resistance to the chemical has been documented since 1946. DDT was banned in the U.S. in 1972 after it was linked to the decline of the bald eagle and other raptors, and it continues to be linked to health problems. A 2007 study finds that women who were exposed to DDT before the age […]
Posted in Chemicals, DDT, Disease/Health Effects, Malaria | 3 Comments »
08
May
(Beyond Pesticides, May 8, 2009) The United Nations Environment Programme (UNEP) and the World Health Organization (WHO), in partnership with the Global Environment Facility, have announced a renewed international effort to combat malaria with an incremental reduction of reliance on the synthetic pesticide DDT. As recently as two years ago, WHO was criticized for promoting DDT as the answer for malaria control in Africa, leading activists to call for increased use of alternatives. DDT has been recognized as a significant human and environmental health risk, including increased risk of breast cancer a wealth of other health concerns, and have built up in waterways and, in particular, the arctic. Now, ten projects, all part of the global program “Demonstrating and Scaling-up of sustainable Alternatives to DDT in Vector Management,” involving some 40 countries in Africa, the Eastern Mediterranean and Central Asia, are set to test non-chemical methods ranging from eliminating potential mosquito breeding sites and securing homes with mesh screens to deploying mosquito-repellent trees and fish that eat mosquito larvae. The new projects follow a successful demonstration of alternatives to DDT in Mexico and Central America. There, pesticide-free techniques and management regimes have helped cut cases of malaria by over 60 […]
Posted in DDT, Insect-Borne Disease, International, Malaria, Resistance | No Comments »
