Espécies vegetais de importância agrícola como fonte alimentar para Coptotermes gestroi Wasmann e outros térmitas (Insecta: Blattodea) nas condições edafoclimáticas do município de Seropédica, RJ

Abstract

Most species of termites, including Coptotermes gestroi, are xylophagous and feed on living or dead wood, in various stages of decay. However, some species exhibit polyphagous feeding habits, also feeding on different parts of living plants such as roots, stems, stalks, etc. C. gestroi is an exotic species from the Indo-Malayan region, and has adapted well to the environmental conditions of Brazil. It is considered a major plague of urban areas, quickly colonizing cities and reaching the border areas between urban and rural places, like the campus of UFRRJ located in Seropédica, RJ. On the other hand, when we see the destruction of natural areas, the trend is for most native termites become relevant plagues as it is happening with Heterotermes and Nasutitermes. In this study we evaluated the attractiveness (frequency) and the feeding preferences (consumption) of termites for plant species of agricultural importance in boundary areas between the urban and the rural places. Nine locations in the city of Seropédica were selected for verification of termite activity, according to records made in previous studies and personal accounts. Around each site of termite activity, baits made of manioc stems and cassava root (Manihot esculenta), pieces of sugar cane (Saccharum officinarum), roots of sweet potato (Ipomoea batatas) and stems of papaya (Carica papaya) were simultaneously placed for 30 days. The chosen position on the ground had an average depth of 15-20 cm; the bait were placed inside PVC pipes with 7.5 cm of diameter, and total height of 15 cm, all equally spaced. The results obtained in the experiment revealed the occurrence of three termites: Coptotermes gestroi Wasmann (Rhinotermitidae), Heterotermes longiceps Snyder (Rhinotermitidae), and Nasutitermes jaraguae Holmgren (Termitidae). C. gestroi occurred on all baits. H. longiceps was only absent in the stem of papaya, and N. jaraguae exhibited activity on the cassava root, sweet potatoes and sugar cane. Consumption of papaya stems, sugar cane and cassava root by C. gestroi was higher than consumption of the root of sweet potato and cassava seed.