Search

Pests that attack the corn crop are cob borers (Helicoverpa armigera Hubner). The pest control can be done using tubal root botanical insecticide (Derris elliptica Benth.). This study aims to obtain the best concentration of tuba root powder extract in controlling the corn cob borer pests H. armigera. Research has been carried out at the Plant Pest Laboratory of Agriculture Faculty, University of Riau. This study used a completely randomized design (CRD) with 6 treatments and 4 replications. The treatments given were several concentrations of tuba root powder extract, namely 0 gr.l−1 of water, 20 gr.l−1 of water, 40 gr.l−1 of water, 60 gr.l−1 of water, 80 gr.l−1 of water and 100 gr.l−1 of water. The parameters observed were initial death, lethal time 50, lethal concentration 50 and 95, daily mortality and total mortality. Daily mortality data obtained from the results of the study were analyzed descriptively and displayed in graphical form, data lethal concentration (LC50 and LC95) were probit analyzed using the POLO-PC program, while other data such as initial death, total mortality, lethal time (LT50), statistically analyzed using a variance. Data from analysis of variance will be continued using the smallest significant difference (LSD) test at the 5% level. The application concentration of tuba root extract with 100 g.l-1 of water is the best concentration to control larvae of H. armigera with an initial time of death 26.50 hours, 67.50 hours of LT50, highest daily mortality on the fourth day by 40% and total larval mortality by 87.5%.

Derris elliptica (Wall.) Benth is a wild plant or weed in agricultural fields that was traditionally used for poisoning fish and plant pests. Several studies showed the low lethal concentration of Derris elliptica root extract to control the laboratory strain Aedes aegypti larvae. This study aimed to evaluate the effectiveness of Derris elliptica root extract against the temephos-resistant Aedes aegypti larvae from the Dengue endemic areas. This experimental study used post-test only control group design with five different concentrations of methanolic Derris elliptica root extract, namely 0.09%, 0.13%, 0.17%, 0.21%, and 0.25%, respectively. Twenty-five of F1 temephos-resistant of wild-caught Aedes aegypti larvae were subjected to each group of the five different concentrations, and two control groups with aquadest. The temephos-resistant strain of Aedes aegypti larvae was determined by bioassay test with temephos -0.02 ppm compound. Mortality rate and lethal concentration (LC50 and LC90) of the larvae were calculated after 24-h contact. Average of mortality rate in each concentration after 24-h contact with Derris elliptica root extract were 32.8%, 49.6%, 72.0%, 95.2%, and 100% with LC50 and LC90 were 1,600 and 2,040 ppm, respectively. The methanolic Derris elliptica root extract have larvacidal potential to control the temephos-resistant Aedes aegypti larvae. Further research to obtain secondary metabolites is needed.

Tuba (Derris elliptica) is one of the insecticide-producing plant which can reduce the pest population due to its active compound, rotenone (C23H2206). The rotenone is deposit in all parts of tuba plant, as such as roots, stems, and leaves. The aim of this research aims was to evaluate the effectiveness of tuba bark extract against subterranean termite Coptotermes sp. The powder of tuba bark extract with 40-60 mesh size macerated with the ethanol by solvent obtains the extract. The extract was made into varions concentration namely 0,5%, 1%, and 1,5%, and applied to the paper disc. There are two types of termite test in this study, namely toxicity test and respiratory test. The mortality of termite and the weight loss of the paper disc were used as indicators of extract activity. The result showed that the concentration of 1,5% indicated the highest mortality from both of two types of test. This study was similar for the lowest weight loss of sample which was also given by concentration 1,5%.