Embrapa Recursos Genéticos e Biotecnologia, PqEB, W5 Norte, P.O. Box 02372, Postal Code 70770-917, Brasília, DF, Brazil.
J Econ Entomol. 2013 Feb;106(1):86-96. doi: 10.1603/ec12092.
The boll weevil (Anthonomus grandis Boheman) (Coleoptera: Curculionidae) is an introduced pest in Brazil, which in 30 yr has successfully expanded to various eco-regions and became the most important pest of cotton (Gossypium hirsutum, Malvaceae). Given the limited knowledge about the adaptive mechanisms that allowed successful establishment of the pest population in a tropical region, in this work we studied the potential of the Midwest population of boll weevils to enter a reproductive dormancy and identified the importance of the feeding source for induction of dormancy. We investigated morphological and physiological characters as indicators of the dormancy. We also investigated the occurrence of reproductive dormancy in boll weevils populations from cotton farms of the Midwestern region of Brazil during the cotton and noncotton seasons of 2009 and 2010. The studies revealed that boll weevils entered facultative reproductive dormancy; however, unlike what has been observed for boll weevils from temperate and subtropical regions, the hypertrophy of fat body and hexamerin levels did not straightly correlated to reproductive dormancy. The food source and field conditions during early adult development were decisive factor for the induction of reproductive dormancy. The incidence of reproductive dormancy increased progressively as the phenology of cotton plant advanced, reaching approximately 90% at the end of the crop season. During the noncotton season, the boll weevil was predominantly found in reproductive dormancy, especially females; however, there is evidence of use of multiple adaptive strategies to colonize the next harvest.
棉铃象鼻虫（Anthonomus grandis Boheman）（鞘翅目：象甲科）是巴西引进的一种害虫，在 30 年内已成功扩展到各个生态区，并成为棉花（棉属，锦葵科）最重要的害虫。鉴于对允许该害虫种群在热带地区成功建立的适应机制的了解有限，在这项工作中，我们研究了中西部棉铃象鼻虫种群进入生殖休眠的潜力，并确定了饲养源对诱导休眠的重要性。我们研究了形态和生理特征作为休眠的指标。我们还调查了巴西中西部地区棉花农场的棉铃象鼻虫种群在 2009 年和 2010 年棉花和非棉花季节中生殖休眠的发生情况。研究表明，棉铃象鼻虫进入了兼性生殖休眠；然而，与温带和亚热带地区的棉铃象鼻虫观察到的情况不同，脂肪体肥大和六倍体蛋白水平与生殖休眠并没有直接相关。食物源和早期成虫发育期间的田间条件是诱导生殖休眠的决定性因素。随着棉株物候的发展，生殖休眠的发生率逐渐增加，在作物季节结束时达到约 90％。在非棉花季节，棉铃象鼻虫主要处于生殖休眠状态，尤其是雌性；然而，有证据表明使用多种适应性策略来定植下一个收获期。
