C-banding characterization of centric fusion and heterochromatin polymorphisms in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae).

This article focuses on the cytogenetic characterization of the water-hyacinth grasshopper, Cornops aquaticum, specifically analyzing the distribution of constitutive heterochromatin to improve identification of chromosomes involved in three polymorphic Robertsonian translocations (centric fusions) and to detect polymorphisms of supernumerary C-positive segments (SS). Cornops aquaticum is a Neotropical semiaquatic grasshopper that exclusively inhabits floating plants of the Pontederiaceae family, including the invasive water-hyacinth Pontederia crassipes, and is considered a potential biological control agent. The study of two Argentinean populations revealed distinctive C-banding patterns that serve as reliable markers for distinguishing the three centric fusions (1/6, 2/5, and 3/4) and identified polymorphic supernumerary heterochromatic segments on several autosomes. These findings contribute to understanding chromosomal variation and evolution in C. aquaticum and provide tools for further ecological and evolutionary research on this species.