Impact of Limited Dispersion Capacity and Natural Barriers on the Population Structure of the Grasshopper Ommexecha virens (Orthoptera: Ommexechidae)

• Published in: Neotropical entomology 2021-10, Vol.50 (5), p.706-715
• Main Authors: de Souza, Tyago Eufrásio, Cruz, Geyner Alves dos Santos, de Moura, Rita de Cássia
• Format: Article
• Language: English
• Subjects: Agriculture; Behavior and Bionomics; Biomedical and Life Sciences; Ecology; Entomology; Life Sciences
• ISSN: 1519-566X; 1678-8052
• DOI: 10.1007/s13744-021-00878-y

The grasshopper Ommexecha virens  Serville has low dispersion capacity, and it is regarded as a specialist, only being found in sandy, dry environments with high incidence of sunlight. Considering these aspects, we evaluated the diversity and genetic structure of O . virens natural populations using ISSR (Inter Simple Sequence Repeat) markers. The data pointed to low expected heterozygosity for some populations ( H E = 0.06–0.09), probably a consequence of positive inbreeding, which is typical of species showing low or null dispersion indices. Moreover, significant genetic differentiation was observed ( F ST = 0.50 and G ST = 0.51), as well as low number of migrants ( N m = 0.47), indicating that the populations are genetically differentiated. This is likely related to the limitation in dispersing and fragmentation of suitable environment localities colonized by O. virens . The populations of O. virens were structured in three genetic groups associated to different landscapes, revealing the presence of a secondary contact zone, possibly arisen from isolation followed by genetic divergence among populations and subsequent gene flow of divergent individuals of O. virens . At last, we found positive isolation by distance (IBD; r : 0.427; P : 0.025) which is an important factor, since it may be adding to the emergence of reproductive barriers among individuals of O. virens that have been experiencing isolation.