Article

Persistence and Inheritance of Costs of Resistance to Imidacloprid in Colorado Potato Beetle

Biology Department, Queens College of CUNY, 65-30 Kissena Boulevard, Flushing, NY 11367, USA.
Journal of Economic Entomology (Impact Factor: 1.51). 01/2008; 100(6):1871-9. DOI: 10.1603/0022-0493(2007)100[1871:PAIOCO]2.0.CO;2
Source: PubMed

ABSTRACT

Reduced fitness among resistant versus susceptible individuals slows resistance evolution and makes it easier to manage. A loss of resistance costs could indicate novel adaptations or mutations contributing to resistance. We measured costs of resistance to imidacloprid in a Massachusetts resistant population compared with a Massachusetts susceptible population in 1999 in terms of fecundity, hatching success, egg development time, and sprint speed. Resistance was additive and seemed to be polygenic with high heritability. The fecundity cost appeared overdominant in 1999, and the hatch rate cost was partly recessive in 1999, but neither was significantly different from dominant or recessive. In 2004, we repeated our measures of resistance costs in Massachusetts in terms of fecundity and hatching success, and we added a new resistant population from Maine. In 2005, we compared development time of Maine resistant and the laboratory susceptible colony eggs. Significant fecundity costs of resistance were found in both population in both 1999 and 2004, and significant egg developmental time costs were found in 1999 and 2005. However, the hatching success costs of resistance were significant in 1999 and not apparent in 2004, suggesting some modification or replacement of the resistance genes in the intervening time.

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Available from: Mitchell B Baker, Jul 24, 2014
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    • "Инсектициды остаются наиболее эффективным средством контроля численности насекомых. Но эффективность их применения снижается из-за формирования резистентности (Stankovic et al., 2004; Рославцева, 2005, 2009; Сухорученко, 2005; Baker et al., 2007; Alyokhin et al., 2008, 2009; Беньковская и др., 2008а; Benkovskaya et al., 2009). Имеющиеся в арсенале агрономов средства защиты картофеля от колорадского жука так же потенциально могут стать факторами формирования новых резистентных популяций и утратить свои изначально ценные хозяйственные свойства (Сухорученко и др., 2006). "
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    DESCRIPTION: Основным способом контроля численности вредителей остается обработка химическими инсектицидами. Эффективность применения инсектицидов снижается из-за формирования резистентности в популяциях вредителей. Это особенно актуальная проблема при борьбе с колорадским жуком. Для замедления развития устойчивости предлагаются разные стратегии применения инсектицидов. На основе данных комплексного многолетнего исследования нами была предложена гипотеза замедления развития устойчивости за счет применения пониженных доз инсектицидов. Мы построили прогностическую дискретную генетическую модель развития устойчивости в популяциях колорадского жука для проверки нашей гипотезы. Модель, основанная на классических уравнениях популяционной генетики, была дополнена действием различных факторов. Расчеты коэффициентов выживаемости особей колорадского жука велись с учетом статистических закономерностей распределения дозы токсического вещества после обработок инсектицидами. Используя логнормальное распределение, мы рассчитали коэффициенты выживаемости разных генотипов при изменении дозы обработки инсектицидами в два и более раз. Дополнительно ввели в модель фактор дифференцированной смертности во время зимовки. Использование фенетических маркеров неспецифической устойчивости к факторам среды позволило провести расчёты модели с опосредованными межгенными взаимодействиями. С использованием данной модели были проверены различные гипотезы в разработке стратегии преодоления резистентности. Расчёты показали, что применение минимально эффективных доз инсектицидов (пониженных доз) приводит к замедлению увеличения доли резистентных особей в популяциях колорадского жука на пару сезонов. При чередовании применения инсектицидов из разных химических классов устойчивость развивается гораздо медленнее. Наиболее оптимальной стратегией является межсезонное чередование применения инсектицидов разных химических классов и обработка пониженными дозами.
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    • "After the designated time periods, the larvae were transferred to the 25 ± 1 °C chamber for 1 h to recover from a possible heat-induced coma (Huang et al., 2009). Following the recovery period, the larvae were taken out of the chamber, and their mortality was recorded at room temperature as failure to move at least one leg after being placed on their backs for 10 sec (Baker et al., 2007). After that, all the larvae were transferred in liquid nitrogen to the -80 °C freezer for the future RNA extraction. "
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    ABSTRACT: The Colorado potato beetle is an important pest of solanaceous plants in the Northern Hemisphere. Better understanding of its physiological responses to temperature stress and their interactions with still-prevalent chemical control has important implications for the management of this insect. We measured mortality and expression of the Hsp70 heat shock proteins in the Colorado potato beetle larvae exposed to sublethal concentration of the commonly used insecticide imidacloprid, and to supraoptimal temperatures. Both turned out to be significant stress factors, although induction of Hsp70 by imidacloprid observed in the present study was low compared to its induction by the heat. The two factors also interacted with each other. At an extreme temperature of 43 °C, exposure to a sublethal dose of imidacloprid resulted in a significant rise in larval mortality, which was not observed at an optimal temperature of 25 °C. Heat-stressed larvae also failed to respond to imidacloprid by producing more Hsp70. These findings suggest that when field rates of insecticides become insufficient for killing the exposed beetles under optimal temperature conditions due to the evolution of resistance in beetle populations, they may still reduce the probability of resistant beetles surviving the heat shock created by using propane flamers as a rescue treatment.
    Full-text · Article · May 2014 · Insect Science
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    • "After receiving the applications, the larvae were placed on excised potato leaßets inside plastic petri dishes. Larval mortality was recorded as the failure to move at least one leg after being prodded by the forceps for 10 s after 24 h of feeding on untreated excised potato foliage (Baker et al. 2007). LD 50 (lethal dose killing half of the exposed larvae) were analyzed in Polo Plus program (LeOra Software 2012). "
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    Full-text · Article · Jan 2014 · Annals of the Entomological Society of America
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