Potential of using phorbol esters as an insecticide against Spodoptera frugiperda

Jatropha curcas oil is a promising candidate for biodiesel production. The oil is also rich in bioactive diterpenoids (phorbol esters, PEs). In the present study, the extracted PEs (PEs enriched fraction, PEEF) from Jatropha oil was evaluated for insecticidal activity against Spodoptera frugiperda (third instar larvae), which is a common pest in corn field across the tropical and subtropical areas. The PEEP exhibited contact toxicity with an LC50 of 0.83 mg ml(-1) (w/v). The corn leaves treated with PEEP also declined the food consumption (33%), relative growth (42%) and food conversion efficiency (38%) at a concentration of 0.25 mg ml(-1) (w/v). Higher reduction (39 and 45%) in the relative consumption rate was observed at 0.625 and 0.125 mg PEs ml(-1) (w/v) of PEEF. Considering the rapid growth in Jatropha biodiesel industry, large amount of PEs can be harnessed, which can be further utilized as a biocontrol agent. (C) 2012 Elsevier B.V. All rights reserved.