Toxicity of extracts of Cyperus rotundus on Diabrotica speciosa

Abstract

ABSTRACT. The objective of this work was to evaluate the insecticidal effect or repellency of Cyperus rotundus, an important weed plant, through alternative methods of extraction, on Diabrotica speciosa, a pest that affects several plant species. The experimental design was completely casual, and consisted of five repetitions. The C. rotundus extracts were prepared using leaves and roots by alcoholic extraction, aqueous (hot water) extraction and aqueous (cold water) extraction and diluted to four different concentrations (0, 5, 10, and 15% of the volume of each extract). These dilutions were then tested and compared with a control. The higher mortality of D. speciosa adults as well as a smaller leaf consumption area were observed after treatments with increasing dosages of different C. rotundus extracts generated by alcoholic extraction (55% of mortality and 28% leaf consumption). Therefore, the alcoholic extract of the C. rotundus foliage is an option for the control of D. speciosa in agroecologic systems.Keywords: rootworm, nutgrass, Chrysomelidae, alternative control. RESUMO. Toxicidade de extratos de Cyperus rotundus sobre Diabrotica speciosa.O objetivo deste trabalho foi avaliar o efeito inseticida ou repelência de Cyperus rotundus, importante planta infestante, por meio de métodos alternativos de extração sobre Diabrotica speciosa. O delineamento experimental foi inteiramente casualizado, com cinco repetições. Os extratos foram elaborados utilizando raízes e folhas de C. rotundus mediante extração alcoólica, aquosa (água quente) e aquosa (água fria) diluindo-se em quatro diferentes concentrações (0, 5, 10 e 15%) em comparação com o controle (água). A maior mortalidade de adultos de D. speciosa, bem como, menor consumo de área foliar foram observadas com o aumento da dose nos diferentes extratos das folhas e das raízes de C. rotundus, destacando-se a extração alcoólica das folhas (55% da mortalidade e de 28% do consumo de folha). Portanto, o extrato alcoólico de folhas de C. rotundus é uma opção para o controle de D. speciosa em sistemas agroecológicos.

Insecticidal potential of some indigenous weeds extracts of Bahawalpur Pakistan againstdusky cotton bug (Oxycarenus hyalinipennis) (Costa) (Hemiptera: Lygaidae) under laboratory conditions

“…Fresh weight (25 %) of the separately picked leaves, stems and roots (25gram) was mixed in 100 % distilled water (100 ml). The mixture was boiled at 100 o C then conditioned until it was cool (Barbosa et al, 2011). Afterwards five concentrations (1%, 5%, 10%, 15% and 20%) of each plant were prepared by dilution with distilled water and these were tested against O. hyalinipennis.…”

“…Leaves of cotton (Gossypium hirsutum) were immersed for 1 minute in each concentration [1%, 5%, 10%, 15% and 20% and control (water only)] of each extract. These leaves were maintained in the shade and under free air for two h until excess water evaporated (Barbosa et al, 2011). After this, 20 O. hyalinipennis freshly emerged adults were released in Petri dishes to check mortality.…”

Larvicidal Effect of Zingiber officinale and Cyperusrotundus Oils on The third Instar Larvae Cephalopinatitillator (L.)

“…Cyperusrotundus L. (Cyperaceae) is a weed that grows in fields and on the canal borders. Cyperus(known as Su'd) is consideredthe main weed species in cultivated soils in tropical areas [25,26]. C. rotundus is rich in alkaloids, nanthraquinone, coumarins, steroids, triterpenes, flavonoids, saponins, tannins, and resins.…”