By applying pesticides to prevent a variety of insects,\nrodents and birds from damaging crops, farmers increased productivity by\nbetween 20 and 50 percent and maximized the benefits of other valuable\nagricultural tools, such as high-quality seeds, fertilizers and water\nresources.<\/p>\n\n\n\n
As pests evolved and developed resistance to pesticides, however,\nthey passed on these genetic factors to their offspring, which resulted in higher\nproportions of these populations becoming pesticide-resistant. The pest control\nindustry then developed stronger and more concentrated treatments, which led to\nfurther increases in pesticide resistance within the targeted populations. Although\nrepeating this cycle with higher and higher treatment concentrations may work\nin the short term, scientists agree it will ultimately lead to increasingly\nresistant populations, a process that threatens to make most pesticides\nobsolete.<\/p>\n\n\n\n
\u201cEvolved resistance to\npesticides is now recognized as one of the most significant problems of modern\ntimes,\u201d said Stephen Shuster, <\/strong>professor\nof invertebrate zoology in NAU\u2019s Department\nof Biological Sciences<\/a>.<\/p>\n\n\n\n Shuster conducted a new study\nfocused on genetic factors that contribute to pesticide resistance in rats, which\nproposes a different approach to pest control through the use of contraceptive\ntreatments. Shuster collaborated on the study, published in the journal Heliyon<\/em><\/a>, with scientists Cheryl Dyer<\/strong>, Loretta<\/strong> Mayer<\/strong> and Brandy Pyzyna<\/strong> of SenesTech<\/a>, a local Flagstaff firm with many\nties to NAU. Dyer was formerly a research professor in NAU\u2019s Department of\nBiology. Mayer is an alumna, earning both her master\u2019s and Ph.D. degrees in biology\nat the university. Pyzyna also earned her master\u2019s degree in biology at NAU.<\/p>\n\n\n\n \u201cOur results have significant implications for the\ndevelopment and application of treatments to manage pests, now and into the future,\u201d\nShuster said.<\/p>\n\n\n\n The team examined a number of pest control approaches,\nincluding three primary solutions already proposed to mitigate this growing\nproblem: withholding treatment altogether; selectively applying treatment; and\napplying treatments in combination. <\/p>\n\n\n\n After running extensive simulations on rat reproduction to\nunderstand the intense selection process that results in evolved pesticide\nresistance, the scientists found that because pesticides and sterilants rarely\neradicate an entire pest population, they impose powerful selection favoring\nthe evolution of resistance to pesticide treatment.<\/p>\n\n\n\n In contrast, contraceptives act to reduce pest population\nsize by targeting particular age classes. This process limits population growth\nand keeps genetic factors that confer resistance at such low frequency that\nthey can be lost from the population by chance. <\/p>\n\n\n\n \u201cOur overall conclusion is that we can mitigate the\nselection responsible for the evolution of pesticide resistance by changing the\nusual goal of pest control treatments. Instead of attempting, and ultimately\nfailing, to destroy or sterilize an entire pest population, we advocate the use\nof contraceptive treatments that primarily act to reduce these species\u2019 rates\nof reproduction, and that leaves as much of the pre-treatment population as\npossible intact,\u201d Shuster said. \u201cWe show that this approach dramatically\nreduces the opportunity for selection favoring the evolution of resistance and\nmay thereby permit the safe and long-term application of pest control measures.\u201d<\/p>\n\n\n\n Shuster\u2019s main research interests are mating system\nevolution, male and female reproductive strategies, community and ecosystem\ngenetics and population biology of marine organisms. In 2017, Shuster was named\nan American Association for the Advancement of Science (AAAS)\nFellow, recognized by his peers for \u201cdistinguished contributions to the\nfields of invertebrate zoology, mating system and sexual selection research,\nand for undergraduate science education and communicating science to the\npublic.\u201d<\/p>\n\n\n\nStudy finds\ncontraceptives have significant implications for pest management <\/strong><\/h4>\n\n\n\n
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