Toxicity of ethyl acetate extract and ricinine from <i>Jatropha gossypifolia</i> senescent leaves against <i>Spodoptera exigua</i> H&uuml;bner (Lepidoptera: Noctuidae)

Abstract

The beet armyworm (Spodoptera exigua (Hübner)) is one of the most important vegetable pests in Thailand. After 24 hr of both dipping and sprayer bioassay, estimation of LC 50 of the ethyl acetate extract of Jatropha gossypifolia senescent leaves demonstrated toxicity to secondary instar S. exigua larvae because in this stage most armyworm start to move to other plants and it is also the first susceptible stage for toxicity tests. Ricinine, the main alkaloid separated from ethyl acetate crude extract, showed toxicity on secondary instar larvae by the sprayer method with an LC 50 of 3,215 ppm whereas the LC 50 value for ethyl acetate crude extract is 8,644 ppm. Thus, the ethyl acetate crude extract of Jatropha gossypifolia senescent leaves may have ricinine as the active ingredient and may be used as an alternative choice for the minimal application of chemical insecticides for Spodoptera exigua.

Antifeedant activity of Jatropha gossypifolia and Melia azedarach senescent leaf extracts on Spodoptera frugiperda (Lepidoptera: Noctuidae) and their potential use as synergists

“…Furthermore, the SLE seems to show a better control efficacy on another related insect species, Spodoptera litura (LC 50 = 6500 mg L −1 ) 7. In addition, J. gossypifolia SLE prepared in ethanol as described here is more potent than J. gossypifolia SLE prepared in ethyl acetate, or than the active ingredient ricinine on S. exigua (LC 50 ∼8644 and 3215 mg L −1 respectively) 34. Similarly, the toxicity of the M. azedarach SLE is higher on S. frugiperda than that observed on S. exigua (LC 50 ∼9800 mg L −1 )35 or on the nematode Haemonchus contorts (LC 50 ∼9200 mg L −1 ) 36.…”

Insecticidal activity of pogostone against Spodoptera litura and Spodoptera exigua (Lepidoptera: Noctuidae)

“…Futhermore, for contact toxicity, a similar result has been obtained by Bullangpoti et al , who found that Jatropha gossypifolia and Melia azedarach senescent leaf extracts exhibited contact toxicity against S. frugiperda . In addition, according to Bullangpoti et al , ethyl acetate extract and ricinine from Jatropha gossypifolia senescent leaves possess contact toxicity against S. exigua . PO in this study showed antifeedant activity and larvicidal activity against S. exigua and S. litura , which clearly revealed that S. exigua was more susceptible than S. litura .…”

“…Among this group, the family Noctuidae is the largest in the order Lepidoptera, which includes some of the most destructive insect pests of crops. In this family, the tobacco cutworm, Spodoptera litura (Fabricius), and the beet armyworm, Spodoptera exigua (Hübner), are two highly polyphagous insect pests of many important crops . Currently, the most common way to reduce worm populations is to apply insecticides, especially chemical insecticides.…”

EFFECT OF POTASSIUM NITRATE ON THE PRODUCTION OF RICININE BY Ricinus communis AND ITS INSECTICIDAL ACTIVITY AGAINST Spodoptera frugiperda

“…Castor bean (Ricinus communis L., Euphorbiaceae) has been investigated for its drying properties, medicinal and insecticidal effects (Rodríguez-Hernández, 2005). Ricinine (3-Cyano-4 methoxy-N-methyl-2-pyridone) is an alkaloid present in castor bean plants (Wang et al, 2009), which (Bigi et al, 2004;Bharadwaj and Sharma, 2007;Ramos-López et al, 2010;Bullangpoti et al, 2011), and whose production can be enhanced by nitrogen (Waller y Yang, 1965).…”