Mortality of Sitophilus granarius (L.) and Rhyzopertha dominica (F.) Adults Exposed to Different Concentrations of Filter Cake in Stored Wheat

Abstract

አህፅሮት
የሲልከን ውሁድ ያሊቸው ግዑዝ ብናኞች የተከዘነ እህልን ከጎተራ ነፍሳት ከመከሊከል አንጻር ከኬሚካሎች ይልቅ ሇአካባቢ ተስማሚ ሇጤናም ጉልህ ጉዳት የማያስከትለ አማራጮች እየሆኑ መጥተዋል፡፡ ከዚህ ጋር ተያይዞ አንድ የሲሉከን ውሁድ ያሇው የማጣሪያ ኬክ ብናኝ በጎተራ ነፍሳት ሊይ የሚኖረውን የመቆጣጠር አቅም ሇመፈተሽ በጎተራ ነቀዝ እና በትንሹ እህል ቦርቧሪ ጥንዚዛ ሊይ ጥናት ተደርጓል፡፡ ጥናቱ የተከናወነው 1ኪ.ግ.፣ 0.75ኪ.ግ.፣ 0.5ኪ.ግ.፣ እና 0.25ኪ.ግ. የማጣሪያ ኬክ ብናኝ በአንድ ኩንታል ስንዴ ሊይ በመጨመር ሲሆን የብናኙን ውጤታማነት ሇመቆጣጠር ምንም ብናኝ ያልተደረገበት ስንዴ ከጎን ተጠንቷል፡፡ ጥናቱ ባጠቃሊይ ሇ14ቀናት የተከናወነ ሲሆን ብናኝ ባሇው ስንዴ ውስጥ የገቡ ጉልምስ ነፍሳት የደረሰባቸው የሞት መጠን ተገምግሟል፡፡ በዚህም መሠረት በጎተራ ነቀዞች ሊይ በሶስት ቀናት ብቻ ከ41.3% እስከ 70.0% የጉልምሶች ሞት የተከሰተ ሲሆን ይህ በትንሹ እህል ቦርቧሪ ጥንዚዛ ጉልምሶች ሊይ ከ73.3% እስከ 93.3% ሞት አስከትሏል፡፡ ከ14 ቀናት በኋሊ ሲታይ በጎተራ ነቀዝ ጉልምሶች ሊይ እስከ 98.7% ሞት ያስከተሇ ሲሆን በትንሹ እህል ቦርቧሪ ጥንዚዛ ሊይ ግን እስከ 100% ሞትን አስከትሏል፡፡ ስሇዚህ በዚህ ጥናት ሊይ የተካተቱ የነፍሳት ዝሪያዎችን በማጣሪያ ኬክ ብናኝ ከሞሊጎደል መቆጣጠር እንደሚቻል መመልከት ይቻሊል፡፡

Abstract
Silica based inert dusts are eco-friendly alternatives to control stored grain insect pests due to environmental and health concerns associated with use of synthetic insecticides. A study was conducted to determine the efficacy of filter cake (a silica-based inert dust) on the granary weevil, Sitophilus granarius (L.) and lesser grain borer, Rhyzopertha dominica (F.) in stored wheat. Filter cake dust of ≤0.4 mm particle size was admixed with 500 g of wheat seed to provide nominal rates of 10000, 7500, 5000, and 2500 ppm (mg/kg), while the control treatment consisted of wheat seeds that were untreated. The bioassays were carried out using a liter-sized plastic jars in completely randomized design with three replications. Experiments were maintained at 23.1±1.7oC and 61.0±4.3% relative humidity. Mortality data were collected at 3, 7, and 14 d after treatment. Results indicated that mean mortality rate at 3 d after treatment ranged from 41.3 to 70.0% in S. granarius and 73.3 to 93.3% in R. dominica. Mean mortality of S. granarius adults at 14 d in filter cake treatments was 84.0 to 98.7%, whereas that of R. dominica was 98.3 to 100%. The present results show that filter cake dusts can be used to control these two species in stored wheat. Filter cake has potential in protection of wheat from S. granarius and R. dominica infestations in storage.