Oviposition deterrent and ovicidal properties of Calotropis gigantea (L.) leaf extract to Paraeucosmetus pallicornis (Dallas) in rice

Abstract

Paraeucosmetus pallicornis (Dallas) is a new pest in Indonesia which decreases rice production and quality. This pest causes the grains to become flat, hollow, brownish, break easily when milled, and bitter. This research represents the first study on Calotropis gigantea extract as an oviposition deterrent and ovicide against P. pallicornis. The study was conducted under laboratory conditions using four extract concentrations i.e. 0.5, 1.0, 1.5 and 2.0%. The oviposition deterrent effect was determined by counting the number of eggs laid and hatched. Percent reproductive control (PRC) and ovicidal activity was calculated using Tennyson’s formula. Results indicated that all concentrations of C. gigantea leaf extract reduced the number of eggs laid and hatched. The PRC also showed a gradual reduction of oviposition of the P. pallicornis and the ovicidal activity ranged between 86.5 and 100%. The extract concentration which showed the highest potential as an oviposition deterrent and ovicide against P. pallicornis was in the range of 1.0–2.0%. The overall results indicated that C. gigantea leaf extract has the potential to be used as an oviposition deterrent and ovicide against P. pallicornis.

Keywords

• Calotropis gigantea
• leaf extract
• ovicidal
• oviposition
• Paraeucosmetus pallicornis