1. Thrips are considered a secondary pest of soybean in Brazil, but high densities have been noticed since the last harvests (2017/18 and 2018/19), yet no study has provided an initial hypothesis regarding the causes of such events.
2. We aimed to identify some of the factors related to Frankliniella schultzei Trybom (Thysanoptera: Thripidae) temporal dynamics in commercial soybean crops located in Tocantins (Northern Brazil).
3. We undertook evaluations during soybean vegetative, flowering, and fruiting stages on 200 plants per field in each sampling date (n = 22). Our results indicated that the densities of F. schultzei were similar among fields and soybean phenological stages.
4. The density of thrips showed a significant negative relationship with rainfall, but it was not related to either air temperature, photoperiod, relative humidity, or wind speed.
5. The predators' density was less than 170 individuals (summing all assessments), and it was not associated with thrips density.
6. This study indicates rainfall as the leading factor associated with the temporal dynamics of F. schultzei in commercial soybean crops.

中文翻译：

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评估巴西北部商品大豆作物中富兰克林氏菌 (Thysanoptera: Thripidae) 的时间动态

1. 蓟马在巴西被认为是大豆的次生害虫，但自上次收获（2017/18 和 2018/19）以来已注意到高密度，但没有研究提供有关此类事件原因的初步假设。
2. 我们的目的是确定位于 Tocantins（巴西北部）的商业大豆作物中与Frankliniella schultzei Trybom（缨翅目：蓟马科）时间动态相关的一些因素。
3. 我们在每个采样日期（n  = 22）对每块田的 200 株大豆在营养、开花和结果阶段进行了评估。我们的结果表明，F. schultzei的密度在田间和大豆物候阶段之间是相似的。
4. 蓟马的密度与降雨量呈显着负相关，但与气温、光周期、相对湿度或风速均无关。
5. 捕食者的密度少于 170 个人（所有评估的总和），并且与蓟马密度无关。
6. 这项研究表明，降雨是与商品大豆作物中F. schultzei时间动态相关的主要因素。