Biomass is an important indicator of various ecological factors in insect populations and communities. Although the utility of this variable is proven, it is usually dismissed in ecological studies, generally, because of the difficulty of measuring it. Considering that insect biomass is apparently declining worldwide, here, we aimed to test the accuracy of forewing length as an estimator of body mass in Neotropical Ichneumonidae to help in monitoring insect biomass. Forewing length and dry body mass were measured in 728 individuals from distinct localities in Venezuela and Ecuador. A clear log-linear relationship existed between the two variables, and a log-linear regression had significant and strong predictive power of mass based on wing length. To derive the final values of mass from predictions made using our equation, we used an exponential transformation. We present an R function for predicting mass from wing length. We consider our findings applicable to many Neotropical species of Ichneumonidae, and helpful especially when specimens are measured in dry collections.

生物量是昆虫种群和群落中各种生态因素的重要指标。尽管该变量的效用得到了证明，但由于测量困难，通常在生态学研究中通常会忽略它。考虑到昆虫的生物量在全球范围内明显下降，因此，我们的目标是测试前向长度作为估计新嗜鱼纲的体重的准确性，以帮助监测昆虫的生物量。对委内瑞拉和厄瓜多尔不同地区的728个人进行了前躯长度和干体重的测量。两个变量之间存在清晰的对数线性关系，对数线性回归具有显着且强大的基于机翼长度的质量预测能力。为了从使用我们的方程式进行的预测中得出质量的最终值，我们使用了指数变换。我们提出一种R函数，用于根据机翼长度预测质量。我们认为我们的发现适用于许多新嗜鱼纲的物种，特别是在干燥收集物中测量标本时特别有用。