Browsing by Author "Osae, M."
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Item Assessment of Bacillus thuringiensis and emamectin benzoate on the fall armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) severity on maize under farmers’ fields in Ghana(Springer, 2021) Koffi, D.; Kyerematen, R.; Osae, M.; Amouzou, K.; Eziah, V.Y.The introduction of fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae) into Ghana is a threat to maize production. This study determined the severity of this pest on maize production subjected to Bacillus thuringiensis (Bt), emamectin benzoate (Eb) sprayed and unsprayed farms under farmers’ practices in Ghana. At least one farm per treatment was selected in each Agro-Ecological Zone (AEZ) for data collection throughout the maize phenology during three production seasons. Percent damaged plants and ears were determined, the proportion of feeding damage on leaves and ears was scored, and yields measured on each farm. Ear damage was most severe in the Guinea Savannah Agroecological Zone with a correspondingly lower yield. The highest yield was recorded from the Tropical Rain Forest zone. The damage levels decreased when plants aged, but the scoring of damage level on attacked ears was greater than that on leaves. Maize plant damage was highest with corresponding lowest yields on unsprayed farms compared to sprayed farms which recorded similar results for both insecticides. Bt and Eb based insecticides (applied at 50g/15L H2O/ha and 75mL H2O/ha, respectively) are efective on FAW larvae and are therefore recommended for FAW management in Ghana.Item Assessment of impacts of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) on maize production in Ghana(Oxford University Press, 2021) Koff, D.; Kyerematen, R.; Eziah, V.Y.; Osei-Mensah, Y.O.; Afreh-Nuamah, K.; Aboagye, E.; Osae, M.; Meagher, R.L.Spodoptera frugiperda was considered an insect pest only in the Americas until its first report in African countries in 2016. In this study, farmers and agricultural officials in Ghana were interviewed on their perceptions and knowledge of the pest, on infestation and maize yield variations across years, and on management practices. Farms were inspected to determine the infestation level of 100 plants per hectare. Interviews revealed that farmers were familiar with the larval stages of this pest and noticed that the pest occurred throughout the year, but populations of S. frugiperda increased only during cropping seasons. Infestation levels reported by farmers in surveys were much lower in 2018 (30.38%) than in 2017 (80.92%). Farm inspections confirmed that infestation levels were much lower in 2018 (20.90%) than 2017 (73.70%). The belt formed by Guinea Savannah, Transitional Zone, and Semi Deciduous Forest Agro-Ecological Zones (AEZs) recorded the highest infestations while the lowest were observed from the Sudan Savannah and Tropical Rain Forest AEZs. Insecticides were the most commonly used tactic to manage populations of this new pest. Maize yields increased across Ghana between 2013 and 2015 from 1.52 to 1.73 t/ha, decreased between 2015 and 2017 to 1.55 t/ha, and increased to 1.69 t/ha in 2018. The impact of fall armyworm injury to maize production is discussed.Item Basic Developmental Characteristics of the Fall Armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), Reared under Laboratory Conditions(Psyche: A Journal of Entomology, 2023) Marri, D.; Mensah, S.A.; Kotey, D.A.; Abraham, J.; Billah, M.K.; Osae, M.Te life cycle of the invasive alien insect pest, fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), was studied using a colony established from feld-collected larvae. Eggs, neonate larvae, and newly emerged adult moths were used in experiments to investigate the basic biology of the FAW. Adult females laid up to 1184 eggs with a mean of 469 ± 22 eggs per female. Te incubation period of eggs and percentage hatchability were 2-3 days and 80–87%, respectively. Te mean larval lengths from the frst to the sixth instar were 4.63, 6.60, 9.76, 15.86, 25.13, and 27.81 mm, respectively. Te mean larval weights were 0.003, 0.019, 0.045, 0.050, 0.060, and 0.067 g, respectively, for the six instars. Te mean width of the head capsule of the sixth instar larva was 2.76 mm. Te total larval duration throughout the six instar stages was 16–18 days, while the mean pupal weight was 0.25 ± 0.001 g and 0.35 ± 0.011 g for males and females, respectively. Te mean pupal length was 14.3 ± 0.16 mm for males and 17.2 ± 0.14 mm for females. Pupal duration ranged from 8 to 14 days, with a mean of 10.35 ± 0.26 days, while the pupal emergence rate ranged from 60 to 94%, with a mean of 80.25 ± 1.28%. Te life cycle of males lasted 33–44 days and that of females lasted 36–49 days under laboratory conditions. Adult copulation occurred between 8 and 11 pm, with the peak occurring at 9 pm. Tis study provides baseline information about the biology of the FAW. Apart from being an important reference point for future research on the FAW, the data provided would aid FAW management decision-making.Item Evaluation of the efficacy of a commercial formulation of beauveria bassiana for the control of the invasive fruit fly bactrocera dorsalis (Diptera: Tephritidae)(Koul Research Foundation, 2016) Marri, D.; Gomez, D.A.M.A.; Wilson, D.D.; Billah, M.; Yeboah, S.; Osae, M.Evaluation of the efficacy of a commercial formulation of Beauveria bassiana (Botanigard® ES) for the control of the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) was carried out on three developmental stages. Botanigard® ES containing 11.3% Beauveria bassiana GHA strain was applied to larvae, pupae and adults at concentrations of 106, 53.0, 26.5, 13.3 and 6.65 (× 106 spores/mL). The effect of B. bassiana on B. dorsalis was dose dependent, increasing with fungal spore concentration. The results showed that an optimum dose of 26.5 × 106 spores/mL killed 50% of adult flies within 4-5 days and 99% within 8-9 days. The same dose reduced adult emergence from infected pupae from 97% in the control to 46% in the treated groups. Fungal treatment at 26.5 × 106 spores/mL also killed almost all adults emerging from pupae and adults treated directly. Comparing methods of fungal application in the field, the result indicated that applying the fungus in fruit fly traps in mango canopies is a better method for fruit fly control in the field as compared to soil surface spray method. However, both methods could be used simultaneously for better results. © 2016 (KRF).Item Maize Infestation of Fall Armyworm (Lepidoptera: Noctuidae) Within Agro-Ecological Zones of Togo and Ghana in West Africa 3 Yr After Its Invasion(Environmental Entomology, 2020-04-29) Koffi, D.; Agboka, K.; Adenka, D.K.; Osae, M.; Tounou, A.K.; Adjevi, M.K.A.; Fening, K.O.; Meagher, R.L.J.The fall armyworm Spodoptera frugiperda (J. E. Smith) invaded several West African countries in 2016 causing severe injury to maize plants and economic damage. This study assesses variations in the occurrence of this species in different Agro-Ecological Zones (AEZs) in Togo and Ghana during the 3 yr following its discovery. The surveys were conducted on 120 farms in Togo and 94 farms in Ghana by collecting larvae from 200 maize plants per hectare. Infestation levels were 68.46% in 2016, 55.82% in 2017, and 17.76% in 2018. The number of larvae recorded per hectare and infestation levels were higher in Togo than in Ghana. The lowest number of collected larvae and infestation levels of S. frugiperda were in 2018, compared to the other 2 yr. Larvae per hectare and the infestation level varied regionally inside the two countries. The southern part of Togo (AEZ five) contained higher numbers of larvae and higher infestation levels during the 2 yr following the invasion of the pest. We concluded that infestation levels of S. frugiperda are much lower in 2018 than the two previous years and it is therefore necessary to determine the factors that affect the population dynamics of S. frugiperda in the field, which is a perquisite for developing management interventions.Item Trapping Spodoptera frugiperda (Lepidoptera: Noctuidae) Moths in Different Crop Habitats in Togo and Ghana(Oxford, 2021) Koff, D.; Agboka, K.; Adjevi, A.K.M.; Assogba, K.; Fening, K.O.; Osae, M.; Aboagye, E.; Meagher, R.L.; Nagoshi, R.N.The economic impact of the invasion of Spodoptera frugiperda (J.E. Smith, Lepidoptera: Noctuidae) into Africa has so far been limited to maize agriculture but could potentially impact many other crops. Trapping based on pheromone lures provides a cost-effective method for detecting this important pest (commonly known as fall armyworm) and will be essential for large-scale monitoring of populations to determine its geographical distribution and migration behavior as the species equilibrates to its new environment. However, the effective use of pheromone trapping requires optimization for a given location. An earlier report demonstrated that two commercial lures (one 3-component and the other 4-component) that were effective for trapping S. frugiperda in maize fields in Togo, Africa. The current study extends these findings to agricultural areas that differ in plant host composition (maize, pasture grasses, rice, and sorghum) in multiple locations in Ghana and Togo. In two seasons, significantly higher numbers of moths were found in maize, and in one season, higher numbers were found in rice than in sorghum and pasture grass systems. The results confirm the effectiveness of pheromone trapping and identify pheromone lures and trapping methods best suited for the different agroecosystems common to West Africa and that are at risk of infestation by S. frugiperda.