Antifeedant activity and toxicity of leaf extracts from Porteresia coarctata Takeoka and their effects on the physiology of Spodoptera litura (F.)

Abstract

Antifeeding and toxic eVects of chemical extracts from Porteresia coarctata Takeoka on the insect pest Spodoptera litura (F.) were investigated in the laboratory. Hexane extracts of P. coarctata leaves were re-dissolved in dimethyl sulfoxide and applied in water to leaves of Ricinus communis L. (castor). A concentration of 1,000 and 2,000 ppm extract exhibited signiWcant antifeeding and toxic eVects to third instar larvae when compared to the same concentration of dimethyl sulfoxide in water as control. One day after feeding on extract-treated castor leaves, the mortality of S. litura larvae was 50%. Mortality increased to 95% after 11 days at a dosage of 2,000 ppm. Compared to the control, third instar larvae fed on castor leaves treated with P. coarctata leaf extract at diVerent concentrations showed signiWcant reduction in protein and DNA content in the fat body and midgut tissues. Results demonstrate the insecticidal and antifeedant properties of P. coarctata leaf extract against the generalist pest S. litura leading to biochemical changes in the insect body. Thus, P. coarctata contains phytochemicals, and the extract, in crude and pure form, has potential as a botanical insecticide in alternative control strategies against Lepidoptera pests.

Fecundity and Survival of Grain Aphid at Various Growth Stages of Waxy and Waxless Triticale

“…Increased surface wax levels were correlated with resistance of cabbage (Brassica oleracea L.) to the aphid, Bravicoryne brassicae L., of sorghum (Sorghum bicolour L.) to the green bug Schizaphis graminum (Rondani), of winter wheat (Triticum aestivum L.) to the English grain aphid S. avenae (F.) [1]. Similarly, Ulrich et al [31] showed the insecticidal and antifeedant properties of Porteresia coarctata Takeoka leaf extract against the generalist pest Spodoptera litura (F.), leading to biochemical changes in the insect body. The chemicals have also been attributed with benefi cial properties as they necessarily represent the fi rst line of contact with organisms [3,11].…”

Antifeedant activity of different solvent extracts of Gliricidia sepium against third instar larvae of Helicoverpa armigera (Hubner) (Lepidoptera : Noctuidae)

“…Several authors have reported that plant extracts possess similar type of antifeedant activity against Helicoverpa armigera (Raja et al, 2005;Baskar et al, 2009;Akhtar and Isman, 2004). Some compounds present affect the feeding behaviour of the insects and inhibit feeding,while others disrupt hormonal balance (Ulrichs et al, 2008). Some plants have been reported as insect repellents, antifeedants, insecticides, ovicides and oviposition deterrents (Dubey et al, 2010 ).…”

Toxicity and physiological effects of some plant extracts on fruit fly infesting ash gourd

“…The active ingredients in neem have the ability to function at hormonal concentrations and produce ecdysone-type effects in susceptible insects (Govindachari et al, 2004). Ulrichs et al (2008) reported that the third instar larvae of Spodoptera litura fed on castor leaves treated with salt grass Porteresia coarctata (Roxb.) leaf extract at different concentrations showed significant reduction in protein and DNA content in the fat body and midgut tissues.…”