Relationship Between Body Mass and Forewing Length in Neotropical Ichneumonidae (Insecta: Hymenoptera).

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.

Potential Spatial Distribution of the Newly Introduced Long-horned Tick, Haemaphysalis longicornis in North America.

The North American distributional potential of the recently invaded tick, Haemaphysalis longicornis, was estimated using occurrence data from its geographic range in other parts of the world and relevant climatic data sets. Several hundred candidate models were built using a correlative maximum entropy approach, and best-fitting models were selected based on statistical significance, predictive ability, and complexity. The median of the best-fitting models indicates a broad potential distribution for this species, but restricted to three sectors-the southeastern United States, the Pacific Northwest, and central and southern Mexico.