Influence of Insecticides on Oviposition Behavior of Western Tarnished Plant Bug on Strawberry
Shimat Villanassery Joseph,
Mark Bolda
Issue:
Volume 2, Issue 4, December 2018
Pages:
36-41
Received:
5 November 2018
Accepted:
19 November 2018
Published:
10 December 2018
DOI:
10.11648/j.aje.20180204.11
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Abstract: Western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae), is a serious insect pest of strawberry in California. Several effective insecticides are applied to manage L. hesperus in strawberry. These insecticides can induce behavioral changes to L. hesperus oviposition such as deterrence and avoidance which are poorly understood in strawberry production. This information can improve integrated L. hesperus management. The objectives of this study were to determine oviposition behavior of adult L. hesperus under 1) no-choice experiment with no insecticide-treated strawberry plant, 2) no-choice experiment with sulfoxaflor, flonicamid and novaluron-treated strawberry plant; and 3) choice experiment with non-treated and sulfoxaflor, flonicamid and novaluron-treated strawberry leaf petioles in semi-field settings. When the distribution of L. hesperus eggs within the non-treated strawberry plants were evaluated at upper, middle and lower strata of the plant as well as at various leaf parts, eggs were uniformly distributed along all three strata of the plant and most of the eggs were found on leaf petiole than on leaf blade, mid-rib or veins. In no-choice experiment, number of the eggs laid by the L. hesperus was significantly lower in the sulfoxaflor-treated than in the non-treated plants. In the choice experiment, number of eggs was significantly greater on non-treated petioles than insecticide- treated when the insecticide was novaluron. There was no difference in L. hesperus egg density between sulfoxaflor or flonicamid-treated and non-treated petioles.
Abstract: Western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae), is a serious insect pest of strawberry in California. Several effective insecticides are applied to manage L. hesperus in strawberry. These insecticides can induce behavioral changes to L. hesperus oviposition such as deterrence and avoidance which are poorly understood in str...
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Diagnostic Study of Planting Time on Sorghum Stalk Borer Infestation and Damage in West Hararghe, Oromia Region, Ethiopia
Abdela Usmael,
Abubaker Terbush,
Gebeyehu Chala,
Kinde Lamessa
Issue:
Volume 2, Issue 4, December 2018
Pages:
42-47
Received:
30 October 2018
Accepted:
5 December 2018
Published:
22 January 2019
DOI:
10.11648/j.aje.20180204.12
Downloads:
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Abstract: Sorghum is the first most important cereal crop in West Hararghe. However, national figure of grain production still remains below than the world's average grain production per unit area due to different biotic and a biotic factor. Among the biotic factors, stalk borer was considered to be the most important insect pests of sorghum and maize in all areas of the country. As a management option different scholars were recommended sowing date. But there was conflicting report on the relationship between sowing time and borer infestation and damage. It was very crucial to identify the better days of sowing in the zone to reduce pest infestation and increase yield of the crop. Thus, this experiment was designed to evaluate the effect of sowing date on infestation of sorghum stalk borer. Chiro varieties was used for experimentation and sown at seven days interval for six weeks starting from 1st onset of rainfall. The treatments were arranged by RCBD design with three replications. Each treatment had a control plot that treated with insecticide chemicals such as carbaryle powders and Alpha cypermethrine. Based on combined analysis results, mean percent infestation was not shown significant variation (P<0.05) over location but highly significant at (P< 0.001) over years. The percent stalk borer incidence on untreated treatment was shown highly significant at (P< 0.001) on both over years and over location. Length of the feeding tunnel and exit holes in sorghum stem and leaves were significantly higher in earlier planted crop than delayed sorghum. As a general, chemicals treatment with early planting double the grain yield at Hirna sub site but, based on pest infestation status late planting was recommended at both location (Mechara and Hirna) to reduce pest infestation and damage.
Abstract: Sorghum is the first most important cereal crop in West Hararghe. However, national figure of grain production still remains below than the world's average grain production per unit area due to different biotic and a biotic factor. Among the biotic factors, stalk borer was considered to be the most important insect pests of sorghum and maize in all...
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