Antitermite Activities of C. decidua Extracts and Pure Compounds against Indian White Termite Odontotermes obesus (Isoptera: Odontotermitidae)

Abstract

In the present investigation, we have tested antitermite responses of Capparis decidua stem, root, flower, and fruit extracts and pure compounds to Odontotermes obesus in various bioassays. Crude stem extract has shown very high susceptibility and very low LD50 values, that is, 14.171 μg/mg in worker termites. From stem extract, three pure compounds were isolated in pure form namely, heneicosylhexadecanoate (CDS2), triacontanol (CDS3), and 2-carboxy-1, 1-dimethylpyrrolidine (CDS8) which have shown very low LD50 value in a range of 5.537–10.083 μg/mg. Similarly, one novel compound 6-(1-hydroxy-non-3-enyl)-tetrahydropyran-2-one (CDF1) was isolated from flower extract that has shown an LD50 8.08 μg/gm. Repellent action of compounds was tested in a Y-shaped glass olfactometer in which CDF1 compounds have significantly repelled termites to the opposite arm. Besides this, C. decidua extracts have shown significant reduction (P<0.05 and 0.01) in termite infestation in garden saplings when it was coated on cotton tags and employed over tree trunks. Further, C. deciduas stem extract was used for wood seasoning, which gave very good results as test wood sticks have shown significantly (P<0.05 and 0.01) very low termite infestation.