4 research outputs found
Control of the white mango scale Aulacaspis tubercularis (Hemiptera: Sternorrhyncha: Diaspididae) with systemic soil drenching insecticides and pruning in greater than ten years old mangos in western Ethiopia
No full textThe white mango scale insect (WMS), Aulacaspis tubercularis Newstead, 1906 is a key pest of mango in Ethiopia, which has been spreading throughout the country since its introduction in 2010. Evaluation of the efficacy of two systemic soil drenching insecticides (thiamethoxam 25 % WG and imidacloprid 35 % SC) independently, and in combination with tree management (pruning) for the control of the WMS was conducted under field conditions in western Ethiopia in two locations in 2018 and 2019. Randomized complete block designs with three replications were used for the experiments. In the first site, all treatments resulted in scale populations that were significantly lower than the control (1086 crawlers and females per leaf). Thiamethoxam 25 % WG at 12 g/tree + pruning resulted in the lowest number of the WMS after the second treatment (43.5 per leaf) followed by thiamethoxam 25 % WG at 18 g/tree + pruning, which was statistically similar. In the second site, imidacloprid 35 % SC + thiamethoxam 25 % WG at 18 g/tree + pruning, resulted in the lowest mean number of the WMS (31.1 per leaf) followed by thiamethoxam 25 % WG at 12 g/tree + pruning (61.4 per leaf). This treatment also gave the highest percentage reduction in number of the WMS compared to the WMS counting before treatment application. This study has shown that use of systemic insecticides and pruning are promising control tactics for the WMS. Cost implications and effects of the insecticides on the natural enemy complex and residual toxicity in fruits need to be evaluated.
To cite: Belay Habtegebriel, Dawit Melisie, Hunde Kidane, Teshale Daba & Ferdu Azerefegn. 2020. Control of the white mango scale Aulacaspis tubercularis (Hemiptera: Sternorrhyncha: Diaspididae) with systemic soil drenching insecticides and pruning in greater than ten years old mangos in western Ethiopia. Israel Journal of Entomology 50(1): 65–73.
http://doi.org/10.5281/zenodo.3987792http://zoobank.org/References/8FA7BF70-B678-420B-9E11-3D87C8F16C7
Virulence of Beauveria bassiana and Metarhizium anisopliae Isolates against the Oriental Fruit Fly Bactrocera dorsalis (Diptera: Tephritidae) Hendel under Laboratory Conditions
No full textአህፅሮት
ከኢትዮጵያ የተገኙ ሰባት የቢቬሪያ ባሲያና (Beauveria bassiana) እና ስድስት የሜታሪሂዚየም አኒሶፓሌ (Metarhizium anisopliae) የፈንገስ ዓይነቶች በቤተ ሙከራ ዉስጥ ሶስት ጊዜ በመደጋገም የፍራፍሬ ዝንብ (Bactrocera dorsalis) ትል እና ሙሽሬ ላይ የመግደል ችሎታ ተሞክሯል፡፡ የጥናቱ ዓላማ የፍራፍሬ ዝንብን በተፈጥሯዊ መንገድ ለመቆጣጠርና IPM ዘዴ ዉስጥ ማካተት ይቻል እንደሆነ ለመመልከት ነዉ፡፡ በዚሁም መሰረት ሁሉም የተሞከሩት የፈንገስ አይነቶች በ 1x108 conidia ml-1 መጠን የፍራፍሬ ዝንብ ትልና ሙሽሬን መግደል ችለዋል፡፡ ነገር ግን የመግደል አቅማቸዉ ከ 40.8% እስከ 96.0% ነበር፡፡ ከመግደል አቅማቸዉ በመነሳት S-39, 34- GM and S-46 የተባለት የሜታሪሂዚየም ዓይነቶች እና S-13 የተባለት የቢቬሪያ ዓይነቶች ከፍተኛ (81.7 to 96%) የመግደል አቅም ነበራቸው፡፡ KF-3 and PPCR-29 የተባሉት የሜታሪሂዚየም ዓይነቶች እና S-39 የቢቬሪያ ዓይነት መካከለኛ (60-80%) የመግደል አቅም ሲኖራቸዉ አንድ የሜታሪሂዚየም የፈንገስ አይነት, GF-3 ፤ እና አምስት የቢቬሪያ ዓይነቶች (9609, 9604, S-46, S-10H and DLCO-41) ደካማ የመግደል አቅም ነበራቸዉ (<60%)፡፡ የመግደል አቅማቸዉ 81.7% እስከ 96% የሆኑ ከፍተኛ ገዳይ በመባል ሲፈረጁ ይህን አቅማቸዉ በተለያዩ 6 መጠኖች (1×104, 1×105, 1×106, 1×107, 1×108, and 1×109ml-10) በተጨማሪ ተገምግሟል፡፡ በውጤቱም ከፍ ባለ መጠን (1×109 Conidia ml-1) የተሞከሩት የሜታሪሂዚየም ዝሪያ የመግደል አቅማቸዉ በትንሽ መጠን (1×104conidia ml-1) ከተሞከሩት በልጦ ታይቷል፡፡ በስድስት የተለያዩ መጠኖች በሙሽሬ ላይም የተሞከረ ሲሆን የሜታሪሂዚየም ዓይነቶች S-46 እና S-39 በከፍተኛ መጠን (1X 109) ግማሽ (50%) የገደሉ ሲሆን የቢቬሪያ ዓይነት S -13 እና የሜታሪሂዚየም ዓይነት 34-GM ከግማሽ በታች ገድለዋል፡፡ S-39 የተባለዉ የሜታሪሂዚየም ፈንገስ አይነት ከሁሉም አነስተኛ LC50 (1.2×104) ሲኖረው፤ 34-GM የተባለዉ ፈንገስ ሁለተኛወ ደረጃ ዝቅተኛ LC50 (በ1.6×104)ነበረው፡፡ በዚህም መሰረት S-39, 34-GM, S-46 የሜታሪሂዚየም ዓይነቶች እና S-13 ቢቬሪያ ፈንገስ ዓይነት የፍራፍሬ ዝንብን በተፈጥሯዊ መንገድ ለመቆጣጠር ተስፋ ሰጪ ሆነዉ ተገኝተዋል፡፡
Abstract
The Oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) Hendel, has become the major pest of fruits in tropical Africa. The objective of the study was to evaluate the virulence of Ethiopian origin entomopathogenic fungal isolates of Beauveria bassiana (Balsamo-Crivelli) Vuillemin and Metarhizium anisopliae (Metchnikoff) Sorokin against the larva and pupa of the oriental fruit fly. Thirteen isolates (seven B. bassiana and six M. anisopliae) were bio-assayed in the laboratory. All the tested isolates were pathogenic to the larvae of B. dorsalis at 1x108 conidia ml-1 concentration with a mortality range from 40.8% to 96%. Isolates S-39, 34-G, and S-46 of Metarhizium and S-13 of Beauveria were categorized as highly virulent (81.7% to 96% mortality), isolate KF-3 and PPCR-29 of Metarhizium and S-39 of Beauveria moderately virulent (61.7%- 78% mortality), and isolates GF-3 of Metarhizium and 9609, 9604, S-46, S-10H and DLCO-41 of Beauveria weakly virulent (40.8-53.3% mortality). Dose-response assay was undertaken on the four highly virulent isolates at six different doses (1×104, 1×105, 1×106, 1×107, 1×108, and 1×109ml-1) on larvae of the fruit fly. The isolates varied in virulence and showed a direct relationship between mortality and concentrations. Isolate S-39 showed the least LC50 (1.2×104) followed by GM-34 (1.6×104), S-46 (1.9x104), and S-13 (1.1x105). The bio-assay on pupae of the fruit fly showed that Metharizium isolates S-46 and S-39 caused about 50% pupal mortality at the highest concentration of 1x109, while the remaining two isolates, S-13 (Beauveria) and 34-GM (Metarhizium), caused below 50% pupal mortality at all concentrations. The four tested isolates are promising bio-agents against B. dorsalis and further field trials are recommended as a component of IPM program.
 
Insecticide resistance management against thrips (Thysanoptera: Thripidae) on onion in the central Rift Valley of Ethiopia
No full textIntegrated Control of the White Mango Scale Through Tree Management and Soil Drenching with a Systemic Insecticide in Western Ethiopia
No full textአህፅሮት
ነጭ የማንጎ ስኬል ሰይንሳዊ መጠሪያው Aulacaspis tubercularis (Hemiptera: Diaspididae) ሲሆን እ.ኤ.አ. በ2010 ዓ.ም. ተከስቶ ኢትዮጵያ ውስጥ የማንጎ ምርትን አደጋ ላይ የጣለ ተባይ ነው፡፡ በመላው አገሪቱ በአጭር ጊዜ ተሰራጭቶ የማንጎ ምርትና ጥራት እንዲቀንስ አድርጓል፡፡ ተባዩን ለመቆጣጠር ከሚወሰዱ ርምጃዎች ውስጥ፤ ፀረ-ተባይ መጠቀም፣የተክል አያያዝን ማሻሻልና በጥገኛ ነፍሳት በመጠቀም በሥነ-ሕይወታዊ መንገድ መቆጣጠር ይገኙበታል፡፡ በማንጎ ተክል ውስጥ ተሰራጭቶ የሚሰራ ፀረ-ተባይን በአንድ ሊትር ውሀ በጥብጦ በተክሉ ዙሪያ ማጠጣትና የማንጎን ቅርንጫፎች መግረዝ (የተክል አያያዝን መጠቀም) ነጭ የማንጎ ስኬል ተባይን ለመቆጣጠር ያለውን ፍቱንነት ለመመርመር እ.ኤ.አ. በ2018 እና 2019 ዓ.ም. በምዕራብ ኢትዮጵያ በሚገኙ ሁለት አካባቢዎች ለተከታታይ ሁለት ዓመታት የመስክ ሙከራ ተካሄዶ ነበር፡፡ ለሙከራው በሶስት ድግግሞሽ የተሰራ ራንደማይዝድ ኮምፕሊት ብሎክ የተባለ ዲዛይን ጥቅም ላይ ውሏል፡፡ በውጤቱም የተባዩ ድምር ቁጥር በሁለቱም ዓመታትና በሁለቱም አካባቢዎች ማለትም ኡኬ እና ባኮ ላይ ውጤታማ በሆነ መልኩ ሊቀንስ ችሏል፡፡ ኡኬ ላይ የማንጎ ተክል ቅርንጫፎችን መግረዝና ቲያሜቶክሳም 25በመቶ WG 18ግራም በአንድ የማንጎ ተክል ዙርያ በአንድ ሊትር ውኃ በጥብጦ መርጨት በመጀመሪያው ዓመት የመጀመሪያ ርጭት ወደ ዝቅተኛ የተባዩ ቁጥር (42.23 በቅጠል) ሲያወረደው በዚያው ዓመት ሁለተኛው ዙር ርጭት ወደ 27.83 በቅጠል አድርሶታል፡፡ ይህንኑ ፀረ-ተባይ በተመሳሳይ ሁኔታ በ12 ግራም መጠን መስጠት ደግሞ የተባዩን ቁጥር በመጀመሪያ ዙር ርጭት 86.83 በቅጠል እንዲሆን ሲያደርገው በሁለተኛው ዙር ርጭት ወደ 61.0 በቅጠል እንዲቀንስ አድርጎታል፡፡ ለማወዳደሪያ ምንም ርጭትም ሆነ መግረዝ ያልተደረገባቸው የማንጎ ተክሎች በመጀመሪያው ዙር ርጭት 334.32 ተባይ በቅጠል እንዲሁም በሁለተኛው ዙር ርጭት 591.29 ተባይ በቅጠል የሆነ ከፍተኛ ቁጥር ታይቶባቸዋል፡፡ ባኮ ላይም የተካሄደው ሙከራ ተመሳሳይ ውጤት አሳይቷል፡፡ይህ ምርምር ከላይ የተጠቀሰውን ዘዴ መጠቀም ተባዩን ለመቆጣጠር ተስፋ ሰጪ ውጤት ያስገኘ መሆኑን አመላክቷል፡፡ ይህንኑ ዘዴ ከሌሎች ማለትም ጥገኛ ነፍሳትን በመጠቀም በሥነ-ሕይወታዊ መንገድ መቆጣጠር ዘዴዎች ጋር ማቀናጀት ያለውን ጠቀሜታና ፀረ-ተባዩ በማንጎ ፍሬ ይዘት ላይ ያለውን ተፅዕኖ በቀጣይ ማጥናት ያስፈልጋል፡፡
Abstract
The white mango scale insect, Aulacaspis tubercularis (Hemiptera: Diaspididae) is a recent threat to mango production in Ethiopia which was introduced in 2010. It has spread to all mango producing areas of the country within a short period of time reducing the production and quality of mangos. Control measures taken against the white mango scale include the use of chemical insecticides, cultural practices and biological control using parasitoids and predators. Field experiments were conducted in western Ethiopia in two locations for two consecutive years in 2018 and 2019 to evaluate the efficacy of integrated application of a systemic soil drenching pesticide and tree management (pruning) for the control of the white mango scale. Randomized complete block designs with three replications were used for the experiments. The total number of WMS life stages varied significantly among the different treatments throughout the two years and application seasons at both Uke and Bako sites. At Uke Thiamethoxam 25% WG at 18g/tree + pruning treated trees showed the minimum mean number of WMS life stages per leaf (42.23) and (27.83) followed by Thiamethoxam 25% WG at 12g/tree + pruning treated trees (86.83) and (61.0) in the first and second application seasons respectively. Control trees showed the highest (334.33) and (591.29) number of WMS life stages in the first and second application seasons respectively. Similar trends were observed at Bako. The study has shown that the integrated use of the systemic soil drenching insecticide and tree management can significantly reduce the WMS life stages on infested mango trees indicating that it is a promising approach to the control of the WMS. Integration of these approaches with other management components such as biological control agents and the effect of the systemic insecticide on the content of the edible fruit deserves further study.
 
