Os Gomphocerinae (Orthoptera: Acrididae) da Região Metropolitana de Belém, Pará

Abstract

The most common grasshoppers known belong to the subfamily "Gomphocerinae, which also has species that are pests of cultivated plants. They are orthopterans with a Neotropical distribution, which can be found from the south of the United States to Argentina. This work is a contribution to the knowledge of the group in the metropolitan region of Belém, Pará, through inventories carried out in the municipalities of Belém, Ananindeua, Marituba, Benevides and Santa Bárbara. The collections were based on active search with an entomological net during 60 minutes in selected localities in the aforementioned municipalities, considering open environments (pastures or meadows) and closed areas (primary forest or old stands). The collected material was treated and identified using dichotomous keys and comparison with previously identified specimens. Four field trips were conducted (Nov-Dec./2005; Feb-Mar/2006), where a total of 212 specimens of Gornphocerinae were obtained (94.4% from open areas and 5.6% from closed areas). Of the total collected, 36.4% are from Belém/Ananindeua; 34.4% from Marituba; 16.9% from Benevides and 12.3% from Santa Bárbara. In Belém/Ananindeua, the occurrence of 5 species was recorded and 4 for the other municipalities studied. The species recorded in the metropolitan region of Belém were: Compsacris pulcher, Orphulella concinnula, Orphulella pelidna, Orpbulella punctata and Amblytropidia sp, where the species O. punctata was more abundant (105 specimens) and Amblytropidia sp was less abundant (7 specimens). As for the occurrence of the species, we observed that Amblytropidia sp was only recorded in Belém/Ananindeua and Marituba, while C. pulcher did not occur in this city, possibly due to the type of vegetation in the selected collection area. In the first two excursions the species had fewer specimens collected and Amblytropidia sp was not observed. The Gomphocerinae in the metropolitan region of Belém are less abundant compared to other subfamilies of grasshoppers. The diversity of species found is relatively satisfactory, considering that only seven species of this subfamily are known to occur in the Amazon region.