An Investigation of the Genetic Variation between Blissus occiduus Barber and Blissus leucopterus leucopterus (Say)

摘要

In Nebraska, there are two chinch bug species that are of major economic importance: the common chinch bug, Blissus leucopterus leucopterus (Say) and the western chinch bug, B. occiduus Barber. The lack of key morphological characters to accurately differentiate between these two species in the immature stage and their extensive overlap of plant hosts and geographic distribution underscore the need to identify molecular markers to distinguish between these two chinch bugs. The objective of this research was to investigate the genetic diversity between B. l. leucopterus and B. occiduus using Amplified Fragment Length Polymorphism (AFLP). Five primer combinations were selected from 20 primer combinations to be used for testing 15 samples of each chinch bug species. The five primer combinations included a total of 151 AFLP markers. Of these, 148 AFLP markers (or 98.01%) were polymorphic between populations. Within B. occiduus, 133 AFLP markers (or 88.08%) were polymorphic and within B. l. leucopterus, 132 AFLP markers (or 87.42%) were polymorphic. Approximately 63% of the variation in the data set could be attributed to genetic variation within the populations according to the AMOVA analysis. Conversely, approximately 37% of the genetic variation occurred between populations. Several distinct molecular markers were identified that can be employed to distinguish between the two species when morphological characteristics show minimal, if any differences, during the immature stages. This research provides a genetic marker that can be used to differentiate between these two economically important chinch bug species. This new diagnostics tool will allow species-specific management options to be employed. In addition, this baseline data can advance future research on chinch bug genetics, including comparisons of additional species.