Browsing by Author "Cudjoe, A.R."
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Item Biological Effects of Neem Oil and Neemazal against the Larger Grain Borer, Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae) on Stored Maize(University of Ghana, 2001-07) Aidoo, I.E.; Obeng-Ofori, D.; Akuamoah, R.K.; Cudjoe, A.R.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)The biological activity of neem oil and neemazal against the larger grain borer, Prostephanus truncatus (Horn) was assessed in maize grain in the laboratory. The bioassays carried out were toxicity of the products against adults and immature stages, effect of the products on progeny production, damage assessment, repellent action and persistency of the products in grain and their effect on seed viability. Neemazal was highly toxic to P. truncatus than neem oil. The highest dosage of 0.8 ml killed 100 % adults of P. truncatus after 72 h exposure but the same dosage of neem oil evoked 70 % mortality after 96 h. The products were also active against the eggs and larvae causing a significant mortality. Neemazal provided greatest protection of maize grains with no noticeable feeding holes on grains treated with 0.6 and 0.8 ml/gm. Both products were moderately repellent to P. truncatus causing less than 50 % repellency. Activity of the two products significantly declined in treated grain after 24 h of storage following treatment. Neem oil and neemazal increased water absorption by maize seeds. Furthermore, seed germination was not affected by neem oil but neemazal significantly reduced seed germination. For the control of P. truncatus in stored maize, neemazal offers greatest protection against both the immature stages and adults. The non-toxicity of neem products to man and other beneficial organisms emphasize the potential use of these products as protectants of farm gate grain storage of small holdings in rural communities in Ghana and other parts of Africa where the neem is abundant.Item Biotype-Host Association and Distribution of Adult Bemisia Tabaci (Genn.) (Homoptera: Aleyrodidae) on Different Host Plants.(University of Ghana, 2000-08) Gadelseed, A.M.A.; Wilson, D.; Cudjoe, A.R.; Offei, K.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)Bemisia tabaci is an important agricultural pest worldwide, which used to be a minor, pest in Ghana but has become a major pest mainly due to the misuse of insecticides. The objectives of this thesis were to examine the occurrence of biotypes, within and between-plant distribution, dispersion and sampling methods for B. tabaci adults on cassava, tomato, okra, garden egg and coral plant. Using cross- infestation, population trends and random amplified polymorphic DNA - polymerase chain reaction (RAPD-PCR) two biotypes were identified. A cassava biotype found on cassava that could survive on cassava, garden egg and eggplant. A non-cassava biotype found on tomato, garden egg and coral plant that survived on all the host plants tested except cassava. The insecticide test did not reveal any differences in population characteristics. Majority of B. tabaci adults were found on upper leaves (1st and 2nd) and bottom leaves (leaves 7th - 9th) on cassava. They were also found on the upper half of the tomato plant and on young and middle aged leaves on garden egg and okra. The insects were aggregated within-plants on tomato, garden egg and okra and between-plants on tomato and okra. The correlation coefficients for insect counts of different sampling units and whole plant counts and sample sizes at particular error levels are presented.Item The cocoa mirid (Hemiptera: Miridae) problem: Evidence to support new recommendations on the timing of insecticide application on cocoa in Ghana(International Journal of Tropical Insect Science, 2014) Adu-Acheampong, R.; Jiggins, J.; Van Huis, A.; Cudjoe, A.R.; Johnson, V.; Sakyi-Dawson, O.; Ofori-Frimpong, K.; Osei-Fosu, P.; Tei-Quartey, E.; Jonfia-Essien, W.; Owusu-Manu, M.; Nana Karikari Addo, M.S.; Afari-Mintah, C.; Amuzu, M.; Nyarko Eku-X, N.; Quarshie, E.T.N.The government's cocoa spraying gangs in Ghana treat about two million hectares of the crop against black pod disease and mirids, the key insect pests of cocoa in West Africa, each August through to December, based on recommendations issued in the 1950s. A few cocoa farmers use additional pesticides. We studied the temporal distribution of two important mirid species, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl., in 1991, 1999, 2003 and 2012 to determine the appropriate timing for the application of control measures in current farming systems. There was a significant correlation between mirid abundance and pod availability on trees, as well as the number of basal shoots and the cocoa variety grown. Mirid populations peaked between January and April and from September to October. Surveys (interviews and focus group discussions involving over 300 farmers in 33 cocoa-growing districts) on pesticide use, sources of recommendations, and perceived successes and failures of current cocoa pest treatments suggested that the 1950 recommendations on the timing of insecticide application need revising. Copyright © ICIPE 2014.Item Damage and weight loss potential of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) on sorghum grain: implication to cereal grain storage in sub-Saharan Africa.(International Journal of Pure and Applied Sciences, 2008) Mailafiya, D.M.; Ayertey, J.N.; Cudjoe, A.R.Item The effect of processing method of cassava chips on the development of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)(African Journal of Agricultural Research Vol. 3 (8), pp. 537-541, 2008) Chijindu, E. N.; Boateng, B.A.; Ayertey, J.N.; Cudjoe, A.R.; Okonkwo, N.J.Susceptibility of processed cassava chips to infestation by the Larger Grain Borer, Prostephanus truncatus (Horn) was investigated in the laboratory (25 - 34°C, 61 - 92% r. h and 12 h: 12 h light: dark regime). Chips of two varieties were variously processed by fermentation, parboiling and sun-drying and stored for different periods. About 150, 200 and 300 g of processed cassava chips in Kilner jars were artificially infested with 15 pairs of P. truncatus adults and stored for 49, 59 and 69 days respectively. Significant differences (P < 0.05) were observed in the mean numbers of adults recorded on the processed chips after 49 days of storage. Across varieties, fermented chips recorded the highest number of adults (407.0 ± 53.9), followed by 395.9 ± 34.5 and 351.0 ± 42.1 adults found on plain and sundried chips, respectively. Parboiled chips however supported the lowest number of adults (89.0 ± 16.4). The number of P. truncatus adults increased with increasing storage period on all chips. The overall mean weight loss recorded on plain, sun-dried and fermented chips were 71.5 ± 7.7%, 71.2, 6.7% and 71.7± 8.8% respectively after 69 days of storage by which time most of the chips had disintegrated completely. The lowest amount of loss, 20.9 ± 5.0%, was recorded on parboiled chips. The study showed that the practice of parboiling confers greater protection to cassava chips against infestation and losses due to P. truncatus than the other traditional fermentation and sun-drying methods.Item Effects of processing, storage time and infestation of dry yam chips by Araecerus fasciculatus (Coleoptera: Anthribidae) on the biochemical components of the yam product in Ghana.(ICIPE PUBLICATIONS, NAIROBI, KENYA, 2008) Danjuma, S.; Ayertey, J.N.; Gbewonyo, W.S.K.; Cudjoe, A.R.Item Effects of Variety and Processed Forms of Cassava Chips on the Development Ofprostephanhs Truncates (Horn) (Coleoptera: Bostrchidae) and Araecerus Fasciculatus (Degeer) (Coleoptera Anthribidae)(University of Ghana, 2002-11) Chuindu, E.; Ayertey, J.N; Cudjoe, A.R.; Gbewonyo, W.S.K.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)Studies were earned out on the effects of variety and processed form of cassava chips on the development of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) and Araecerus fasciculatus (Degeer) (Coleoptera: Anthribidae). Additionally, changes in the nutrient composition of the chips due to infestation, and the influence of major nutrients on the population parameters of these insects were also studied Statistical analysis of insect preference to the processed chips in a choice test revealed that adults of A. fasciculatus significantly (P<0.05) preferred sun-dried and fermented chips to parboiled and plain chips. On the other hand, no significant difference (P> 0.05) was observed in the preference of these chips by P. truncatus adults, suggesting that P. truncatus selection of chips occurred mostly by chance. A susceptibility test and adult development at 25-34°C and 61 -92%r h were conducted to further understand the factors responsible for the differences in the processed chips P. truncatus density increased on fermented chips but this was not significantly different (P>0.05) from the densities recorded on plain and sun-dried chips. However, on parboiled chips low adult densities were recorded and this was significantly different (P< 0.05) from other processed forms Similar studies with A. fasciculatus also revealed the same trend This suggested that in parboiled chips, conditions are less favourable for higher oviposition, larval development and survival of adults and thus constitute a less susceptible form of cassava chips for storage Percentage weight loss due to the two pests in separate studies suggested that P. truncatus caused more damage to the chips compared to A. fasciculatus Weight loss and frass produced by both insects followed almost the same was similar on all the processed form, although A. fasciculatus development was slightly prolonged in sun-dried chips. Insect infestation caused noticeable changes in the nutrient composition of the cassava chips Starch content decreased in both P. truncatus and A. fasciculatus infested samples. There was an increase in the sugar content of parboiled chips infested by the two insects whereas sugars in plain, sun-dried and fermented chips were reduced Correlation analysis revealed relationships between the nutrient composition of the chips and the population parameters of the insects Significant positive association (r=0.71, P<0.05) was found between starch content and P. truncatus density Alternatively, A. fasciculatus density showed a significantly positive association (r=0.77, P<0.05) with non-reducing sugar and negative association with reducing sugar (r= -0 70, P<0.05). The study has shown the importance of parboiling of cassava as opposed to other processing forms and its effectiveness in conferring protection to chips as a management strategy against losses due to P truncatus and A. fasciculatus Changes in the nutrient contents of cassava due to infestation and the relevance of the significant association of the nutrients and population parameters of the insects are also discussed.Item Efficacy of Neem oil and Neemazal against the Larger Grain Borer, Prostephanus truncatus (Horn) in stored maize(Journal of Ghana Science Association, 2009) Boateng, B.A.; Aidoo, I.E.; Obeng-Ofori, D.; Cudjoe, A.R.; Akuamoah, R.K.The biological activity of neem oil and Neemazalon adult and immature stages of the larger grain borer, Prostephanus truncatus, as well as on its F1 progeny was assessed in stored maize in the laboratory. Repellency and persistency effects of the treatments in grain as well as the effect of the treatments on grain damage were also determined. Neemazal was more toxicto P. truncatus than neem oil. The highest dosage of 0.8ml/200g grain killed 100% adult P. maculatus after 72 h exposure but the same dosage of neem oil resulted in 70% mortality after 96h. The products also caused significant (p<0.05) mortality in P. truncates eggs and larvae, Neemazal provided greater protection to maize grains with no noticeable boreholes on grains' treatedwith 0.6 and 0.8ml/200g grain. All treatments repelled less that 50% P. truncatus adults. Activity of the two product significantly declined (0<0.05) in treated grain after 24 hour of storage following treatment. Neemaza loffered greater protection against both immature stages and adults of P. truncatusin stored maize.Item Studies on Damage by Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae) And Araecerus Fasciculatus (Degeer) (Coleoptera: Anthribidae) to Dried Yam Chips(University of Ghana, 2002-11) Danjuma, S.; Ayertey, J.N.; Cudjoe, A.R.; Gbewonyo, W.S.K.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)In West Africa, especially Nigeria, Benin Republic, Togo and Ghana, dried yam chips constitute an important food material. The recent introduction of the larger grain borer into Africa and its devastating effect on cassava chips necessitated a study of the biology and damage caused by Prostephanus truncatus (Horn) (Coleoptera: Bostrichidea) and Araecerus fasciculatus (Degeer) (Coleoptera: Anthribidea) on dried yam chips in Ghana. Three yam varieties were investigated in the studies; these were: “Asaana” and “Pona” (Dioscorea rotundata Poir) and “Afasie” (Dioscorea alata L.). The dried yam chips were obtained following different treatments as follows: Parboiled oven-dried, Non-parboiled oven-dried, Parboiled sun-dried and Non-parboiled sun-dried. Two hundred grammes of each treatment of dried yam chips were placed in a glass jar and ten insects of P. truncatus and A. fasciculatus were placed in each separately as single cultures. Mixed cultures with a starting population of twenty insects: ten insects from each species of P truncatus and A. fasciculatus and a control were also set up. The studies were carried out for three durations: one month, two months and three months at 30 } 3°c and 70 - 92% R.H. The proximate compositions of dried yam chips were also investigated before and after infestation by P truncatus and A. fasciculatus. P. truncatus survived and established on all the treatments processed from the three varieties of yams. However, A. fasciculatus did not survive on oven-dried yam chips, but survived and established on sun-dried yam chips. Ten adults of P. truncatus (age 0-7days) produced 578 progeny and ten adults of A. fasciculatus (age 0-14 days) produced 328 progeny after three months of storage. The mixed culture with a starting population of twenty insects produced 501 progeny (322 of P. trucatus and 179 of A. fasciculatus) after three months of storage. Based on varietal differences, “Afasie” dried yam chips supported the highest progeny of P. truncatus and A, fasciculatus which was significantly more than that supported by “Asaana” and “Pona”. There was no significant difference between the number of progeny supported by “Asaana” and “Pona”. Therefore, “Afasie” dried yam chips were the most susceptible to infestation by P. truncatus and A. fasciculatus. P truncatus survived and established more significantly on dried yam chips processed from the three varieties than A. fasciculatus. Consequently, the percentage damage and weight loss produced by P. truncatus was high. The highest percentage weight loss produced by P. truncatus was 94.91% while A. fasciculatus produced 91.51% after three months of storage. Parboiled sun-dried yam chips and non-parboiled sun-dried yam chips in all the varieties used recorded the highest weight loss by P. truncatus and A fasciculatus. P truncatus produced significant weight loss on parboiled oven-dried yam chips and non-parboiled oven-dried yam chips for all the varieties of yam used for the studies, while A. fasciculatus did not, as it was unable to survive and breed on these chips. Based on varietal differences, P. truncatus and A. fasciculatus produced the highest weight loss on Afasie dried yam chips which was significantly more than those produced on “Asaana” and “Pona”. There was no significant difference in weight loss produced between “Asaana” and “Pona”. The proximate composition of the varieties of yam used for the studies showed slight differences after infestation by P. truncatus and A. fasciculatus. moisture increased significantly, while fat, ash, protein and fibre show no significant difference after infestation, carbohydrate, decreased significantly. Reducing and non-reducing sugars decreases drastically after infestation. Decreases in proximate compositions may be due to degradation and use by the insects for their biological activities. Based on these studies, P. truncatus was found to multiply rapidly and was more destructive than A. fasciculatus. Parboiled oven-dried yam chips and non-parboiled oven-dried yam chips were less damaged by P. truncatus but were not damaged by A. fasciculatus. P. truncatus and A. fasciculatus significantly damaged the parboiled sun-dried yam chips and non-parboiled sun-dried yam chips. Also the presence of insects on dried yam chips leds to increases or decreases in some proximate compositions. It can be concluded therefore that, “Asaana” and “Pona” are significantly better than “Afasie” for the production of yam chips that can be stored for longer periods.Item Suitability of sorghum grain for the development of the Larger Grain Borer Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)(Science World Journal, 2007) Mailafiya, D.M.; Ayertey, J.N.; Cudjoe, A.R.