Browsing by Author "Hiruy, Berhanu"

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    Status, Species Composition and Management of Stored Maize Grain Insect Pests In Hadiya and Silte Zones of Southern Ethiopia
    (Addis Ababa University, 2018-06-02) Hiruy, Berhanu; Getu, Emana (PhD)
    . Status, Species Composition and Management of Stored Maize Grain Insect Pests in Southern Ethiopia Berhanu Hiruy, Addis Ababa University, 2018 Maize (Zea mays L.) is a major staple food and feed sources for millions of people in Ethiopia in general, and Shashogo and Sankura districts of Hadiya and Silte zones, in particular. However, insect pests, both in the field and in the storage seriously threatened its production and consequently, affect food security of the poor farmers. The most important of these have been proven to be Lepidopteran stalk borer and Coleopteran maize weevil. However, no or few studies were conducted on indigenous methods and practices used by farmers in storing and protecting maize grains, as well as the species composition and the status of insect pests of stored maize and the associated losses in the study area. Thus, the survey using face to face semi-structured interviews and farmer’s participatory discussions were conducted in six major maize growing localities of Hadiya and Silte zones of Southern Ethiopia for documenting various indigenous practices and methods used by farmers in protection of their grains from insect pests at different storage periods (3, 6 and 9 months) in 2013/2014 and 2015/2016, using a nested design. Moreover, level of infestation, distribution and the status of insect pests of stored maize, and the associated damage and loss in four farmer’s traditional storage methods were conducted in six localities or peasant-associations for three storage periods (3, 6 and 9 months) in the same year. Besides, laboratory studies were conducted on botanicals, inert dusts, varietal resistance and their integration in the management of maize weevil during the period/ year of 2016/2017. The survey result demonstrated that farmers harvested maize in between November and January. Hand picking was the most commonly used harvesting method. Maize harvesting was commonly done in December. Farmers used different traditional storage methods (facilities) and store their maize either shelled or unshelled. However, most farmers (≥ 82%) store their maize grain unshelled for 7-9 months. Most farmers (52.7%) used outdoor Gotera for storing their maize grain. Through the survey, over thirty arthropods were recorded in stored maize grains from the study area. Of these, nineteen were primary and secondary pests, seven were mold feeders and five were natural enemies. The 19 primary and secondary pests include Sitophilus zeamais (Motschulsky), Sitotroga cerealella (Olivier), Sitophilus oryzae (Linnaeus), Tribolium castaneum (Herbst), Tribolium confusum (Jacquelin duVal), Cryptolestes ferrugineus (Stephens), Cryptolestes pusillus (Schonherr), Rhyzopertha dominica (Fabricius) Oryzaephilus surinamensis (Linnaeus), Tribolium destructor (Uyttenb.), Palorus subdepressus (Wollaston), P. ratzeburgii (Wissmann), Ephestia cautella (Walker), Acarus siro (Linnaeus), Plodia interpunctella (Hubner), Gnatocerus cornutus (Fabricius), Tribolium audax (Halstead), C. iii pusilloides (Steel and Howe) and Prostephanus truncatus (Horn). Of these primary and secondary pests, S. zeamais, S. cerealella, S. oryzae, T. castaneum, T. confusum, C. ferrugineus, C. pusillus and R. dominica were found to be the most abundant, and frequently occurring and were found to be the major pests. Insects such as O. surinamensis, T. destructor, P. subdepressus, P. ratzeburgii, E. cautella, Acarus siro, P. interpunctella and G. cornutus were found to be the next abundant, and frequently appearing and were found to be intermediate pests. However, T. audax, C. pusilloides and P. truncates were found to be the least abundant, least frequently occurring and were minor pests. Besides, from seven species of mold feeders recorded, Carpophilus dimidiatus was the most commonly occurring and the most important, followed by Liposcelis sp. and L. entomophila. But, Typhaea stercorea, C. freeman, C. hemipterus and Brachypeplus sp. were found to be the least commonly appearing and the least important. Among the five species of natural enemies recorded, one species of predatory mite, Cheyletus sp., two species of hymenopteran parasitic wasps; Anisopteromalus calandrae and Cephalonomia tarsalis and coleopteran Staphylinidea were the most abundant and frequently occurring. However, Dactylosternum abdominale recorded rarely. Significantly (P < 0.05) higher level of insect pest infestation, grain damage and losses were recorded in all tested traditional storage methods, the highest being in polyethylene sac, followed by storage in the living house and store room, while the minimum was from in the Gotera out door. Hence, various traditional methods and practices used by farmers were found to be inefficient to provide sufficient protection of grain against insect pests. Thus, there is a need to look for alternative control methods such as varietal screening, botanical control and the integration of compatible control options are paramount importance which are the main focal areas of this PhD thesis. Accordingly, from varietal screening study involving twenty one maize grain varieties, 6 varieties such as Melkasa-6Q, MH-138Q, SPRH, BHQPY-545, AMH-760Q and Gibat (AMH-851) were found to be resistant. Hence, these resistance varieties could be used and adopted as ecologically sound and effective management method to reduce loss by S. zeamais under subsistence farmer’s storages. However, their mechanisms of resistance need further study. Besides, the laboratory studies also confirmed that all of the different traditional or bio-rational methods tested were significantly (P < 0.05) effective in protection stored maize grain against maize weevil. Of which, integration two botanicals (C. aurea and M. ferruginea) and two colored inert dusts (red and white) with the top three resistant varieties; Melkasa-6Q, MH-138Q and SPRH were the most effective, followed by botanicals and inert dusts, respectively at the rates of 5 and 10%. However, their evaluation regarding their effect on human being, natural enemies and cost effectiveness under subsistence farmer’s storage conditions is necessary before wide implementation of the outcomes these studies.
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    Studies on the Effect of Host Type and Textures on the Survival Of Tribolium Castaneum (Coleoptera: Tenbrionidae) Parental and Filial Generations
    (Addis Ababa University, 2010-06) Hiruy, Berhanu; Getu, Emana (PhD)
    The development of Tribolium castaneum (Herbst) was studied at two levels of grain breakage (10, 50%), milled (flour) and whole grain of 20 g different grains or hosts (maize, barely, wheat, sorghum, chick pea, faba bean, field pea and haricot bean) that were purchased from Markato. These 10 and 50% broken, whole flour, and whole grain (control) were kept in an oven at 40 C for four hours to disinfest from internal infestation. Then 20 g of each of the four distinct textures (including the control) of the grains were put in 32 one liter capacity glass jars each and adults (seven pairs), 1-3 days old T. castaneum were introduced in each jar containing 20 g of each of the three distinct textures of the grains. Following this, the different textures of the grains in each of the 32 glass jars were kept under laboratory condition (27±2 ºC and 60-65% relative humidity) and female beetles were allowed to lay eggs for 20 days after which all dead or live insects were removed. Thereafter, the treatments were left and checked daily until larva, pupa and adult emergence respectively. Larvae, pupae and adults’ emergence was recorded subsequently 12, 5 and 20 days in succession after the first larva, pupa and adult emergence in each treatment and replicate. The experiment was set up in a completely randomized design in three replications in Addis Ababa university of Ethiopia for two generations. The result obtained indicated that adults’ survival and progenies development of T. castaneum in whole and broken grains derived from eight local hosts or grains mentioned above were varied. Survival of parental adult beetles was significantly lower (P< 0.05) in whole than in broken grains and flour in all cereal grains. Significantly (P< 0.05) higher mean number of Larva, pupa and adult progenies emergence of T. castaneum was recorded in whole milled cereal grains than in whole grains of cereals and in both the control and all other forms of pulses (Chick Pea, Faba Bean, Field Pea and Haricot Bean) both in the 1st and 2nd generations. Significantly (P< 0.05) higher number of T. castaneum larvae, pupae and adults progenies were recorded in whole milled, 50% and 10% grain breakage of cereal grains, respectively than in whole grain (the control) of cereals and in both the control and all other forms of pulses. Besides, significantly less (P< 0.05) number of T. castaneum larvae, pupae and adults progenies were recorded in almost all forms of pulses than in all forms of the cereal grains, except the control. The results also showed that in damaged cereal grains more larvae, pupae and adults progenies were emerged during the first generation than in the second. Moreover, significantly less (P< 0.05) number of larvae, pupae and adults were emerged in whole grains in the 1st and 2nd generations when compared with the number of larvae, pupae and adults developed in broken and milled grains of cereals.