Effect of extracts of two Amazonian Fabaceae on Cryptotermes brevis (Walker) (Isoptera: Kalotermitidae)

Abstract

In urban centers, the most important genera of termite pests are Cryptotermes (Kalotermitidae), Coptotermes (Rhinotermitidae) and Nasutitermes (Termitidae). Results obtained with plant extracts for termites control show that they may be a potential cheap control method. In Brazil, the phytopharmacological collection is still understudied, more investigations on the biological proprieties of forests species that present toxicity to xylophagous insects are needed. The goal of this paper is to test the antifeedant and repellent potential of Tachigali paniculata and Peltogyne venosa (Fabaceae) against Cryptotermes brevis (Walker) (Isoptera: Kalotermitidae). Ethanolic tested extracts were obtained from P. venosa and T. paniculata bark. The experiment was performed in Petri dishes containing filter paper impregnated with 0.1; 1; 2; 5 and 10% concentrations of cited extracts. Each Petri dish was considered as an experimental unit, containing ten pseudo-workers and a soldier. The experiment was observed during 30 days. Bark extracts from P. venosa and T. paniculata presented antifeedant activity (p < 0.0001) for C. brevis, however, only P. venosa showed an increase in mortality when compared to other treatments (P < 0.001, F_3.76 = 27.296). Tests with extracts from other parts of the plants in question are recommended for future studies. Furthermore, we suggest the use of solvents with different polarities for new mortality tests, since the preliminary studies identified potential insecticide compounds, like alkaloids and saponins.