Study On The Potential Of Some Botanical Powders And Nimbecidine For The Management Of Sesame Seed Bug (elasmolomus Sordidus Fab.) (hemiptera Lygaeidae) In Humera Northwest Ethiopia
Sesamum indicum is one of the oldest oil seed crop grown for its high oil content in manyrncountries. Elasmolomus sordidus is the major pest of sesame seeds both in field and storagerncondition. This experiment was done to evaluate the efficacy of Pyrethrum (Chrysanthemumrncinaraefolium), neem (Azadirachta indica), birbira (Milletia ferruginea) and nimbecidine oilrnfor the management of the series sesame seed pest, E. sordidus as alternative managementrnoptions of synthetic pesticides. The bug was reared in the field on sesame seeds as a feed andrnthe other test in the laboratory at 32±20C and 50 to 60% RH. Powder of pyrethrum, neem,rnbirbira, and nimbecidine oil were tested under laboratory condition for its ability to protectrnsesame seeds against E. sordidus with respect to adult and nymph mortality, egg inhibitionrnand seed weight and oil loss. For comparison standard check malathoin and untreated sesamernseeds were included. Moreover treated sesame seeds and bagging materials were provided tornevaluate the efficacy of treated seeds against weight loss due to E. sordidus. In additionrntreated sesame seeds in open plastic buckets were also provided in highly infested area tornevaluate the efficacy of the botanicals against uncontrolled visitors of sesame seed bug bothrnin weight loss and mean mortality. Hundred percent mortality of adult and nymph of E.rnsordidus were obtained with Pyrethrum powder at all levels of concentrations after 24 hourrnexposure time. About 100% mortality was also obtained in all concentrations of neem andrnbirbira after 48hrs after treatment application. Nimbecidine also achieves >90% nymph andrn>70% adult mortality 48 hrs after treatment application. Sesame seeds treated with thernbotanicals also achieved excellent egg inhibition up to >70% in pyrethrum. Sesame seedsrntreated with neem and nimbecidine showed low weight loss than Malathion treated seedsrnafter 50th day storage in the shade area due to the E. sordidus. In the treated sacks neem andrnnimbecidine showed lower weight loss than the others but there was no difference fromrnMalathion. In open bucket lowest weight loss, oil loss and highest mortality of uncontrolledrnvisiting seed bug was recorded in pyrethrum than the other treatments with no recorded oilrnloss in the closed control. Accordingly, these results indicated that the use of powders of therntested plants and nimbecidine can give effective control of the most important pest of storedrnsesame seed E. sordidus.rnKeywords: Elasmolomus sordidus, sack treatment, seed treatment, uncontrolled visitors,rnshade, plant powders, weight loss