CONICET | Buscador de Institutos y Recursos Humanos

Grasshoppers are one of the most representative groups of herbivorous insects in the steppe wetlands of northern Patagonia. These environments are important because of their environmental and ecological functions, including the provision of food resources for domestic livestock. Consequently, it is important to evaluate the effects caused by grasshoppers during outbreaks on crops and vegetation in natural areas, as well as the feeding behaviour that they present. In order to evaluate the diet of two grasshopper species from northern Patagonia, their host plant consumption was compared using the two most abundant species known to be included in their diet in the field (Juncus balticus and Trifolium repens). Dichroplus elongatus and D. vittigerum were collected during the summer season of 2018, in the province of Río Negro. A total of 63 adults of D. elongatus and 74 of D. vittigerum were collected using an entomological net. They were transported to the laboratory where they were maintained under semi controlled conditions. To evaluate feeding behaviour, a series of no-choice experiments were performed. After 48 hs individuals were fed with the plants J. balticus and T. repens. The amount of plant consumed (response variable) was obtained using the difference in plant weight from the beginning and the end of the experiment. The results exhibit significant differences in plant consumption between both species of insects. The amount of consumption of J. balticus was higher than T. repens for D. elongatus, but for D. vittigerum the opposite was observed. These results suggest that both species present different feeding behaviour preferences under semi-controlled conditions. The study of the diet of native insects that inhabit steppe wetlands in northern Patagonia provides useful information for pest control programs and contributes to the conservation and preservation of these valuable environments.