Universidade Estadual da Paraíba - UEPB, Programa de Pós-graduação em Ciências Agrárias, Campina Grande, PB, Brasil.
Empresa Brasileira de Pesquisa Agropecuária, Laboratório de Entomologia, Centro Nacional de Pesquisa de Algodão, Campina Grande, PB, Brasil.
Braz J Biol. 2021 Sep 22;83:e248154. doi: 10.1590/1519-6984.248154. eCollection 2021.
The cotton boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a key cotton crop pest in Brazil. Adverse climatic factors, such as high temperatures and low soil moisture, dehydrate oviposited cotton squares (bud flowers) on the ground and cause high mortality of its offspring within these plant structures. The objective of this research was to evaluate the mortality of the cotton boll weevil in drip and sprinkler irrigated cotton crops. The experimental design was in randomized blocks with two treatments: drip (T1) and sprinkler (T2, control) irrigated cotton crops with sixteen replications. Each parcel had one emergence cage, installed between two cotton rows per irrigation system, with 37 cotton squares with opened oviposition punctures and yellowish bracts, to capture adult cotton boll weevils. The average number of boll weevils that emerged from the cotton squares and the causes of mortality at different development stages were determined per treatment. Third-generation life tables of the boll weevil were prepared using the natural mortality data in drip and sprinkler irrigation treatments and plus actual, apparent and indispensable mortality rates and the lethality of each mortality cause. We conclude that the application of water directly to the root zone of the plants in a targeted manner, using the drip irrigation system, can cause high mortality of the cotton boll weevil immature stages inside cotton squares fallen on the ground. This is because the cotton squares fallen on the drier and hotter soil between the rows of drip-irrigated cotton dehydrates causing the boll weevils to die. This is important because it can reduce its population density of the pest and, consequently, the number of applications of chemical insecticides for its control. Thus, contributing to increase the viability of cotton production, mainly in areas of the Brazilian semiarid region where the cotton is cultivated in organic system.
棉铃象甲，Anthonomus grandis grandis Boheman（鞘翅目：象甲科），是巴西棉花作物的主要害虫。不利的气候因素，如高温和低土壤水分，会使地上的已产卵棉铃（花蕾）脱水，并导致其后代在这些植物结构内死亡率升高。本研究的目的是评估滴灌和喷灌棉花作物中棉铃象甲的死亡率。采用随机区组设计，设两个处理：滴灌（T1）和喷灌（T2，对照）棉花作物，每个处理有 16 个重复。每个小区安装一个成虫笼，每个灌溉系统的两排棉花之间安装一个，每个笼子里有 37 个有产卵孔和黄色苞片的已开放棉铃，以捕获成虫棉铃象甲。每个处理的死亡率确定方法是计算从棉铃中出现的象甲的平均数量和不同发育阶段的死亡原因。使用滴灌和喷灌处理的自然死亡率数据，以及实际死亡率、表观死亡率和不可避免死亡率和每个死亡率原因的致死率，编制了三代棉铃象甲生命表。我们得出结论，使用滴灌系统将水直接定向施用于植物的根区，可以导致掉落在滴灌棉花行间干燥和炎热土壤上的地上棉铃中棉铃象甲未成熟阶段的高死亡率。这是因为滴灌棉花行间的土壤更干燥、温度更高，掉落的棉铃会脱水，导致象甲死亡。这一点很重要，因为它可以降低害虫的种群密度，从而减少控制害虫所需的化学杀虫剂的使用次数。因此，这有助于提高棉花生产的活力，特别是在巴西半干旱地区，那里的棉花是在有机系统中种植的。
