The development, survival, and reproduction of ectothermic organisms such as insects are strongly influenced by temperature. Because insects respond to temperature by accelerating or reducing their development rate, population growth is directly associated with temperature variations. Here, daily minimum and maximum temperatures and degree-day model approaches were used to estimate the number generation per year (voltinism) of Mythimna sequax Franclemont, Neoleucinodes elegantalis (Guenée), Spodoptera cosmioides (Walker), and Spodoptera eridania (Cramer) over a 34-year period in southern Brazil. Additionally, we assessed the effects of El Niño Southern Oscillation (ENSO) events on voltinism. While an increased number of generations were estimated in warmer regions, comprising mainly northwestern Paraná, fewer generations were estimated in the colder regions of Santa Catarina and Rio Grande do Sul. For all species, the location was the factor that explained most of the variation observed in voltinism (average of 76.9%). Inter-annual changes in voltinism also varied depending on location, and differences of up to five generations among years were obtained in colder regions. On the other hand, ENSO events had a minor influence on the species voltinism. Our findings provide an important contribution to the understanding of spatio-temporal variations in voltinism of insects, and how temperature changes may increase their population growth.

昆虫等变温生物的发育、生存和繁殖受到温度的强烈影响。由于昆虫通过加速或降低其发育速度来响应温度，因此种群增长与温度变化直接相关。在这里，每日最低和最高温度以及度-日模型方法用于估计Mythimna sequax Franclemont、Neoleucinodes egalalis (Guenée)、Spodoptera cosmioides (Walker) 和Spodoptera eridania 每年的数量（voltinism）(Cramer) 在巴西南部超过 34 年的时间。此外，我们还评估了厄尔尼诺南方涛动 (ENSO) 事件对伏廷作用的影响。虽然估计在较温暖的地区（主要包括巴拉那西北部）的世代数有所增加，但在较冷的圣卡塔琳娜州和南里奥格兰德州，估计的世代数较少。对于所有物种，位置是解释在伏定作用中观察到的大部分变化的因素（平均为 76.9%）。伏廷作用的年际变化也因地点而异，在较冷的地区，年间差异可达五代。另一方面，ENSO 事件对物种伏定作用的影响较小。我们的发现为理解昆虫伏廷作用的时空变化做出了重要贡献，