| abstract | Presented here are results of a survey conducted from 1967-1970 to determine the species of eriophyid mites in South Dakota.
Eriophyids are vectors of several plant viruses and are known to produce other types of damage to their hosts, such as galls, blisters, rusting, witchesʼ-broom, proliferation of tissues and leaf rolling. Therefore, attention was focused on collecting plants showing these obvious abnormalities. Many other plants not showing these symptoms were examined for free living eriophyid species.
Specimens were prepared and preserved following Keiferʼs method as well as other preservation techniques. Species discussed are illustrated with line drawings, photomicrographs and some scanning electron micrographs.
Taxonomic status of the different species was determined by comparison and correlation with the previously reported eriophyids. Problems were encountered in correlating these species with those recorded by European workers because of the loss of type materials and inadequate description available in the literature. Keiferʼs and those of others re-descriptions of the European and North American species were utilized in this study, as well as the records of host specificity. The use of host specificity, however, has its own limitation because of cases were a species of eriophyids had been reported on a number of not only closely related hosts, but also on plants of different families, such is the case of Eriophyes douglasiana (Wilson and Oldfield) found in South Dakota, where it was collected on two host plants belonging to two different families.
Most of the previous workers gave little attention to variation or morphological features in the development of eriophyid classification. In the course of this study it was most interesting to note the variation of characters within a given population known to be a single species. Variations observed are discussed separately under each particular species. Also included are the interpretations of attributes of certain complex groups and a discussion of the probable conspecificity of some previously described species.
It is evident that biological studies are needed to clarify these morphological variations in many species. Perhaps emphasis should be placed on the biosystematic approach in treating the taxonomy of Eriophyoidea. There are still many aspects unkonwn in the life histories of this group of Acarines that need to be learned.
The present study records 48 different species of eriophyid mites from South Dakota; six of these are described and named as new species.
A conspectus of the species reported in this paper is listed in each of the main families. |