Avaliação da repelência de extratos vegetais sobre a barata Periplaneta americana (L.) visando controle alternativo de pragas e a redução de impactos ambientais

Abstract

This study aimed to evaluate the repellent effect of plant extracts on Periplaneta americana (L.). For testing aqueous 10% laurel (Laurus nobilis Linn. 1753), eucalyptus extracts were used (Corymbia citriodora Hook. 1995), chinaberry (Melia azedarach Linn. 1753), castor bean (Ricinus communis L.), blemish (Myrcia cauliflora Berg.) and jambolan (Syzygium cumini Lam) and neem (Azadirachta indica A. Juss). We used a PVC pipe ring with a petri dish lined with filter paper containing 1 ml of extract and more 3g substrate. 10 nymphs were released and the evaluations done in times of 5 minutes and 1, 4, 8, 12 and 24 h, and counted the number of insects on contact with the extract for 5 repetitions. Based on the repellency index (RI), neem extracts (IR = 0.65), castor (IR = 0.67), Blonde (IR = 0.72), eucalyptus (IR = 0.89) and jambolan (IR = 0.90) were repellent as extracts blemish (IR = 1.12) and cinnamon (IR = 1.43) were attractive by index. The results provide relevant data regarding alternative control Periplaneta americana, which further studies may lead to the development of repellents thereby minimizing the usage of chemicals.