A Comment: Functional Feeding Groups as a Taxonomic Surrogate for a Grassland Arthropod Assemblage

Abstract

M. Mlambo (2011) raises very valid points in his commentary on our paper (Buschke & Seaman 2011). Although much can be said about the merits (or lack thereof) of our study, we limit our rebuttal to the four points specifically raised by Mlambo. The first point, that assigning functional feeding groups (FFG) is simpler than assigning family level, is rightfully contested by Mlambo and our paper did not provide quantitative evidence of this. Certain FFG cannot be assigned without traditional taxonomic efforts but many others can. For example, although large families such as Scarabaeidae and Muscidae cannot easily be assigned to FFG without further identification, many orders, such as adult Odonata, Neuroptera and Orthoptera, and superfamilies, such as parasitoid Ichneumonoidea and the piercing/sucking Pentatomoidea, share broad feeding styles. Based on our experience, we believe that on average it is simpler to assign FFG than other taxonomic levels. Mlambo's assertion that Kaiser et al. (2009) provide empirical evidence against the use of FFG is unfounded: their study also lacked quantitative evidence of taxonomic difficulties and their judgements were as subjective as ours.