Insecticidal and antifungal activities of saline extract from Abarema cochliocarpos bark against pests with relevance to human health and agronomy

During the last decades, there has been an increasing interest in natural compounds for the control of insect pest. The present study evaluated the insecticidal activity of a saline extract of Abarema cochliocarpos bark against Aedes aegypti, Sitophilus zeamais, Nasutitermes corniger, and Fusarium spp. Thin layer chromatography revealed the presence of anthraquinones, saponins, and hydrolyzable and condensed tannins in the extract. High-performance liquid chromatography with a diode-array detector confirmed the presence of gallic acid, catechin, ellagic acid, and catechin derivatives. The presence of lectins and trypsin inhibitor was also confirmed. The extract exhibited insecticidal activity against the fourth-stage larvae of A. aegypti (LC50 - 8.22 mu g/mL). Furthermore, the extract did not exhibit insecticidal activity against the adults of S. zeamais even 7 d after treatment. However, a strong deterrent effect was observed. The extract promoted the mortality of N. corniger workers and soldiers (LC50: 1.89 and 1.83 mg/mL, respectively). The extract (0.2-0.8 mg/mL) inhibited the mycelial growth of F. oxysporum (69.0%-83.1% inhibition) and F. lateritium (23.0%-59.0% inhibition). These results indicate that the bark of A. cochliocarpos is a source of bioactive agents that are effective against insect and fungal pests.