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Öğe Evaluation of microbial and repellent insecticides for control of migratory grasshopper, Melanoplus sanguinipes (Fabricius), in Colorado(2006) Demirel, N.; Cranshaw, W.The migratory grasshopper, Melanoplus sanguinipes (Fabricius) (Orthoptera: Acrididae), is one of the most important grasshoppers in western North America rangelands in Fort Collins, CO (USA). The laboratory bioassay trials were conducted to determine the specific effect of microbial insecticides and repellents for control of migratory grasshopper in Fort Collins, Colorado. In an initial trial, both Beauveria bassiana and spinosad treated foliage produced significant mortality to grasshoppers at 120 h post-exposure, with some more rapid mortality within 24 h when spinosad was used at a higher rate. Significant mortality from B. bassiana was first observed after 72 h, with the high rate (1 lb/100 gal concentration). In a second trial treatment with Bioneem, Trilogy (neem oil), and Garlic Barrier were also included all treatments caused significant mortality at 96 h, with significantly most mortality with B. bassiana and spinosad. At 192 h, B. bassiana and spinosad produced 100% mortality. In conclusion, Beauveria bassiana and Spinosad were effective microbial insecticide for reducing population density of migratory grasshopper in both laboratory bioassays trials. In addition, Bioneem had significant repellent effects on migratory grasshoppers. © 2006 Academic Journals Inc.Öğe Evaluation of plant yield responses to artificial infestations of Lygus elisus (Van Duzee) and Nysius raphanus (Howard) on spring canola(Asian Network for Scientific Information, 2007) Demirel, N.; Cranshaw, W.A two-year study was conducted to evaluate the relationship of plant yield responses to artificial infestations of the Pale Legume Bug (PLB) and False Chinch Bug (FCB) on spring canola in Colorado, USA. Yield losses with both insect species were greater at early flower stages infestations than at early pod stages infestations. A significant yield reductions were caused by 8 PLB/head at early flower stages and 16 PLB/head both stages of IMC204 and 16 PLB/ head at early flower stages of IMC205. Significant yield losses in 2001 were resulted in 40 FCB/head at early pod stages of IMC204. However, yield losses in 2002 were significantly higher at early flower stages than early pod stages. A 20 and 40 FCB/head resulted in 72 and 85% yield losses comparing with 0FCB/head on the cultivar IMC204. In addition, the cultivar IMC205 had 79% yield losses by 40 FCB/head. In conclusion, the spring canola yield responses varied among PLB and FCB/head and their stages. © 2007 Academic Journals.Öğe Evaluation of relative host plant preferences of Western Black Flea Beetle, Phyllotreta pusilla Horn (Coleoptera: Chrysomelidae), for various canolas and mustards in greenhouse and field in Colorado(2006) Demirel, N.; Cranshaw, W.All trials were conducted in 2000, 2001 and 2002 with different canola (Brassica napus L.) and mustard (Brassica juncea (L.) plants to evaluate the relative host plant preferences of Western Black Flea Beetle (WBFB) Phyllotreta pusilla Horn (Coleoptera: Chrysomelidae) in greenhouse and field conditions in Colorado (USA). The spring mustard (ZEM1) and winter mustard (Debut) were significantly attractive and more susceptible for the WBFB. However, the spring mustard (W1-23) was less susceptibility to WBFB and suggests a possible source of reduced susceptibility in oilseed mustards. Most of currently registered varieties of canola were susceptible to WBFB feeding. The spring canola (CO1) was significantly more attractive and susceptible for the WBFB. In addition, spring canola (Helios) sustained relatively high plant injury with WBFB and plant had low population density and suggesting in tolerance to WBFB injury. © 2006 Asian Network for Scientific Information.Öğe Permethrin treatment of pollination bags as a protecting from false chinch bug, Nysius raphanus (Howard) (Hemiptera: Lygaeidae), injury to canola in Colorado(Elsevier Sci Ltd, 2006) Demirel, N.; Cranshaw, W.The false chinch bug (FCB), Nysius raphanus (Howard) (Hemiptera: Lygaeidae), is one of the most important pests on the Brassicaceae plants in Colorado (USA), commonly in large numbers on developing canola, particularly after flowering. Aggregations occur in breeding trials on bags used to control pollination. Sprays of permethrin, but not pyrethrins, applied to the bags significantly reduced numbers of FCB for at least 12 days after application. This reduction resulted in a 25-79% increase in yields compared with untreated bags. (c) 2006 Elsevier Ltd. All rights reserved.Öğe Plant yield response to artificial infestation of the false chinch bug, Nysius raphanus, confined on spring canola(Priel Publ, 2006) Demirel, N.; Cranshaw, W.A 2-year study was conducted to evaluate the relationship of plant yield responses to artificial infestations of the false chinch bug (FCB) Nysius raphanus (Howard) on spring canola in Colorado, USA. Yield losses were greater when infestation occurred at the early flowering stage (EFS) than at the early pod stage (EPS), in both 2001 and 2002. In the first trial in 2001, with infestations of 10, 20 and 40 FCB/head, the respective average yield losses over all cultivars were 43%, 68% and 69%, respectively, compared with the non-infested control at the EFS, but 11%, 26% and 23% at the EPS. In the second trial in 2001, with infestations of 10, 20 and 40 FCB/head, the respective average yield losses over all cultivars were 26%, 58% and 55% at the early EFS, but 35%, 20% and 35% at the EPS. Yield reductions from FCB infestation were lower in 2002 than in 2001. In the first trial in 2002, with infestations of 10, 20 and 40 FCB/head, the respective average yield losses of all cultivars combined were 31%, 51% and 68% at the EFS, and 13%, 32% and 18% at the EPS. However, in the second trial in 2002, with the same numbers of FCB per head, no yield reductions were observed at either EFS or EPS. The number of FCB causing 10% yield loss in the four trials ranged from 6.1 to 39.4 FCB/head (avg. 14.8) following infestation at the EFS and 15.4-109.8 (avg. 41.8) following infestation at the EPS. Cultivar responses to FCB may also influence FCB yield reductions. However, in these studies all eight tested cultivars sustained yield loss in at least one trial at some FCB infestation level. Variation between trials was substantial but a significant level of resistance to FCB injury did not occur among the tested cultivars.Öğe Relative attraction of color traps to western black flea beetle, Phyllotreta pusilla horn (Chrysomelidae: Coleoptera), on spring canola in Colorado(2006) Demirel, N.; Cranshaw, W.The Western Black Flea Beetle (WBFB), Phyllotreta pusilla Horn (Chrysomelidae: Coleoptera), is one of the most significant pests on the spring canola in Colorado (USA). Different color traps were tested to learn of attraction to WBFB. Yellow, neon yellow, neon green and neon orange sticky color traps were the most attractive for WBFB. However, the blue and silver sticky color traps were less attractive to WBFB. © 2006 Asian Network for Scientific Information.Öğe Relative effect of color mulches to potato/tomato psyllid, Paratrioza cockerelli (Sulc) (Homoptera:Psyllidae), on garden tomato plants(2006) Demirel, N.; Cranshaw, W.A 2-year study was conducted to evaluate relative effect of color mulches to potato/tomato psyllid, Paratrioza cockerelli (Sulc.) (Homoptera: Psyllidae), on tomato plant in Fort Collins, Colorado (USA). In the first year, an aluminum mulch and white plastic mulch resulted in significant reduction on potato/tomato psyllids on tomatoes (c.v. 'Celebrity') comparing with the black plastic mulch and untreated check. The white plastic mulches continued to suppress psyllids in the second evaluation. In the second year, an aluminum mulch significantly decreased number of psyllid on tomato plants (c.v. 'Roma') comparing with other treatments (straw, black plastic, bare ground control). In conclusion, the aluminum and white plastic mulch can be used as an alternative cultural control to the chemical control for controlling potato/tomato psyllid in home garden tomato plants in Colorado. © 2006 Academic Journals Inc.Öğe Surveys of false chinch bug, Nysius raphanus (Howard) (Hemiptera: Lygaeidae) and their movement on cultivated crops and non-cultivated habitats throughout growing season in Colorado(2006) Demirel, N.; Cranshaw, W.A three-year survey was conducted to evaluate population density of False Chinch Bug (FCB), Nysius raphanus (Howard) (Hemiptera: Lygaeidae) and their movement on cultivated crops and non-cultivated habitats throughout the growing season in Colorado (USA). The first population of the FCB appeared winter mustard such as Flixweed, Descurainia spp., in Larimer and western weld County in Colorado. Within a wide host range, they moved from alfalfa after cutting to adjacent crops, i.e. canola and caused significant injury during early flower and pod stages. They also moved to canola from wild mustards, flixweed, D. sophia L. and tansy mustard, D. pinnata (Walt.), which were present in both non-cultivated areas and cultivated crops. Furthermore, the dry weather condition might be increased the activity and outbreak of FCB on the cultivated crops and non-cultivated habitats, whereas the heavy rain was decreased the population density of FCB. Knowing the population density of FCB and their movement on cultivated crops and non-cultivated habitats is important to predict their injury to canola plants and for developing new control strategies. © 2006 Academic Journals Inc.Öğe Surveys of Lygus spp. and their movement on cultivated crops and non-cultivated habitats throughout growing season in Colorado(2006) Demirel, N.; Cranshaw, W.A three-year survey was conducted to evaluate population density and movement of Lygus species on cultivated crops and non-cultivated habitats throughout the growing season in Colorado. Three Lygus species, L. elisus, L. hesperus, L. lineolaris, were commonly found in cultivated crops and non-cultivated habitats based on concurrent adult collections in Colorado. Lygus species were found from early April to late in August, having multiple generations in each year in Colorado. Lygus species had wide host range in Colorado. Alfalfa was a significant host plant for Lygus species. However, after cutting alfalfa, Lygus species moved to adjacent crops, i.e. canola and caused significant injury during early flower and pod stages. The wild mustards, flixweed, D. sophia L. and tansy mustard, D. pinnata (Walt.), were significantly important host plants in non-cultivated areas and within cultivated crops. Removing wild mustard in sampling area resulted in the movement of Lygus species to canola crop. In conclusion, it might be important to know population density of Lygus species and their movement on cultivated crops and non-cultivated habitats to predict their injury to canola plants to develop control strategies. © 2006 Asian Network for Scientific Information.Öğe Yield responses of pale legume bug, Lygus elisus (Van Duzee) (Heteroptera: Miridae), on spring canola(Asian Network for Scientific Information, 2007) Demirel, N.; Cranshaw, W.The pale legume bug (PLB), Lygus elisus (Van Duzee), is one of the most important pests on canola plant in Colorado. A two-year study at early flower and pod stages of spring canola was conducted to evaluate plant yield responses for PLB in 2001-2002. Artificial infesting of number of PLB per head at early flower stages resulted in high yield losses than infestations at early pod stages in both years. In 2001, averaged yield losses for seven canola cultivars at early flower stages were 66, 63 and 72% and for five canola cultivars were 54, 66 and 63% with infested at 2, 8 and 16 PLB per head, respectively, compared to the non-infested control. However, such significant effects on yield following PLB infestation at early flowering were not repeated at both trials in 2002. In 2001, averaged yield losses for seven canola cultivars at early pod stages were 22, 34 and 50% with infested at 2, 8 and 16 PLB per head and for five canola cultivars was 49% with infested 16 PLB per head. In addition, significant yield losses at early pod stages occurred on cultivar 46A65 when infested at the highest level at second trials in 2002. The comparisons of 10% yield loss occurred with infestations of 3.1-5.6 PLB per head (avg. 3.7) at early flowering stage and 3.4-19.0 PLB per head (avg. 9.6) at early pod stage infestations in both years. In conclusion, the proposal of economic injury levels for infested different number of PLB might be changed between 3.1-5.6 PLB per head at early flower stages and 3.4-19.0 PLB per head at early pod stages. © 2007 Academic Journals.
