The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a major pest of commercial cotton (Gossypium hirsutum) in the southern United States and throughout Central and South America. Efforts are underway to develop a PCR-based diagnostic tool that can be used to rapidly and accurately differentiate boll weevils from other weevil species that are commonly captured in pheromone traps. However, the quantity and integrity of weevil DNA must be sufficient for a successful PCR assay. Currently, active eradication programs service traps weekly, but post-eradication programs service traps at 2- or 3-wk intervals. Consequently, captured weevils may be dead, dismembered, and exposed to environmental conditions for prolonged periods which may adversely affect the quantity and quality of weevil DNA. We documented DNA quantity and integrity in boll weevils and weevil body parts aged in traps over a 3-wk period under field conditions. The quantity of DNA extracted from whole weevils, heads, abdomens, and legs generally remained sufficient (> 1 ng/μl) for successful PCR amplification throughout the 21-d period. The integrity (fragment length) of extracted DNA declined over time but generally was sufficient (> 700 bp) for successful amplification. PCR amplification of three marker genes validated that the quality and integrity of DNA extracted from dead weevils and individual weevil body parts aged in traps up to 21 d remained at sufficient levels for the PCR-based assay. However, our data also suggested that rain events may accelerate degradation of weevil DNA.

中文翻译：

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评估捕获的棉铃象鼻虫（鞘翅目：Curculionidae）的 DNA 完整性，用于新的基于 PCR 的诊断工具

棉铃象鼻虫 Anhonomus grandis grandis Boheman (Coleoptera: Curculionidae) 是美国南部和整个中美洲和南美洲商业棉花 (Gossypium hirsutum) 的主要害虫。正在努力开发一种基于 PCR 的诊断工具，该工具可用于快速准确地将棉铃象鼻虫与通常在信息素陷阱中捕获的其他象鼻虫物种区分开来。然而，象鼻虫 DNA 的数量和完整性必须足以进行成功的 PCR 检测。目前，主动根除计划每周为陷阱提供服务，但根除后计划以 2 或 3 周为间隔提供陷阱服务。因此，捕获的象鼻虫可能会死亡、肢解并长时间暴露在环境条件下，这可能会对象鼻虫 DNA 的数量和质量产生不利影响。我们记录了田间条件下在陷阱中老化 3 周的棉铃象鼻虫和象鼻虫身体部位的 DNA 数量和完整性。从整个象鼻虫、头部、腹部和腿中提取的 DNA 量通常保持足够 (＞1 ng/μl) 以在整个 21 天期间成功进行 PCR 扩增。提取的 DNA 的完整性（片段长度）随时间下降，但通常足以成功扩增（＞700 bp）。三个标记基因的 PCR 扩增验证了从死象鼻虫和在陷阱中老化长达 21 天的单个象鼻虫身体部位提取的 DNA 的质量和完整性保持在基于 PCR 的测定的足够水平。然而，我们的数据还表明，降雨事件可能会加速象鼻虫 DNA 的降解。