Ovicidal and toxic effects of crude leaf extracts of Clerodendrum inerme, Clerodendrum splendens, Clerodendrum multiflorum, Vitex negundo and Argemone mexicana were evaluated against the castor semilooper, Achaea janata L. (Noctuidae: Lepidoptera) using different bioassay methods. Among the extracts tested, the highest ovicidal activity was observed in C. splendens as well as A. mexicana with LD50 values of 7.65 and 9.14 mg-1, respectively. Leaf extracts of A. mexicana and C. inerme were toxic to both third and fourth instar larvae of A. janata through topical application. However, the extracts of A. mexicana and C. inerme found to be more toxic to third instar larvae with 70 and 73 per cent mortality, respectively. The lowest LD50 value of 5.33 mg-1 was recorded by A. mexicana extract and was followed by C. inerme extract with LD50 value of 7.26 mg-1. Present results indicated that A. mexicana and C. inerme plants have potential to use in IPM programme. 
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Ovicidal and toxic effects of certain plant extracts to the castor semilooper, Achaea janata L. (Noctuidae: &nbsp;Lepidoptera)

Background: Although use of synthetic insecticides causes excellent control of insect pests, it leads to adverse effects on non-target organisms as well as the environment. The present study determining the chemical composition and insecticidal activities of essential oil extracted from the leaves of rough cocklebur, Xanthium strumarium and its bioefficacy against the castor semilooper, Achaea janata shall show a new dimension in formulating an ecofriendly management strategy towards castor crop. 
 
Methods: Xanthium strumarium leaf essential oil was isolated through hydro-distillation method using Clevenger apparatus and the chemical composition was analysed using GC-MS. The ovicidal and insecticidal activity of the essential oil was determined by dipping and topical application methods, respectively. Larval feeding deterrence and growth inhibitory properties of the essential oil was evaluated through the diet incorporation method.&nbsp; 
 
Result: GC-MS analysis of the X. strumarium essential oil revealed the presence of 14 chemical compounds, of which the majority are the terpenes (94.48%). The LC50 values in terms of ovicidal and insecticidal activities were recorded to be 69.70 &micro;L/mL and 0.30 &micro;L/larvae, respectively. The fifty per cent larval feeding deterrence (DC50) and growth inhibitory properties (EC50) were recorded to be 1.88 &micro;l/cm&sup2; and 213.94 &micro;L/mL, respectively.

Ovicidal and toxic effects of certain plant extracts to the castor semilooper, Achaea janata L. (Noctuidae: Lepidoptera)

Bio-efficacy of Xanthium strumarium L. Essential Oil against Castor Semilooper, Achaea janata L. (Lepidoptera: Noctuidae)