Spatial Distribution and Sampling Plans for Four Species of Cereal Aphids (Homoptera: Aphididae) Infesting Spring Wheat in Southwestern Idaho

1992 ◽  
Vol 85 (3) ◽  
pp. 830-837 ◽  
Author(s):  
Ming-Guang Feng ◽  
Robert M. Nowierski
Keyword(s):  
Spatial Distribution ◽  
Spring Wheat ◽  
Cereal Aphids ◽  
Sampling Plans

SPATIAL DISTRIBUTION AND SAMPLING PLANS WITH FIXED LEVELS OF PRECISION FOR CEREAL APHIDS (HOMOPTERA: APHIDIDAE) INFESTING SPRING WHEAT

1998 ◽  
Vol 130 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Philip J. Boeve ◽  
Michael Weiss
Keyword(s):  
Spatial Distribution ◽  
Power Law ◽  
Spring Wheat ◽  
Rhopalosiphum Padi ◽  
Aphid Population ◽  
Management Decision ◽  
Cereal Aphids ◽  
Sampling Plans ◽  
Taylor’S Power Law ◽  
Taylor's Power Law

AbstractThree cereal aphids, Rhopalosiphum padi (L.), Schizaphis graminum (Rondani), and Sitobion avenae (F.), invade wheat fields in the northern Great Plains each spring, and populations occasionally reach economic levels. The first objective of this study was to describe the spatial distribution of three species of cereal aphids infesting hard red spring wheat (Triticum aestivum L.). The second objective was to develop two sampling plans for cereal aphids using individual stems as the sampling unit, a sampling plan with fixed levels of precision and a sequential sampling decision plan based on total numbers of aphids present. Aphid population estimates were collected from 47 eastern North Dakota spring wheat fields during 1993–1995. The number of aphids per stem were counted on 100–350 stems per field. Taylor’s power law and Iwao’s patchiness regression were used to analyze the spatial distribution of the aphids. Rhopalosiphum padi and S. avenae exhibited an aggregated distribution, whereas S. graminum was distributed randomly in the field. Taylor’s power law provided a better fit to the data than Iwao’s patchiness regression. Sample size requirements for precision levels of 0.10, 0.15, and 0.25 were estimated with Taylor’s regression coefficients. Required sample sizes increased with decreased aphid populations and increased levels of precision. The two sampling plans presented should be useful for research on cereal aphid population dynamics and pest management decision making in spring wheat.

Spatial Distribution and Sampling Plans for Mesoplatys ochroptera (Coleoptera: Chrysomelidae) on Sesbania

2002 ◽  
Vol 95 (2) ◽  
pp. 499-506 ◽  
Author(s):  
G. SILESHI ◽  
J. BAUMGÄRTNER ◽  
S. SITHANANTHAM ◽  
C. K. P. O. OGOL
Keyword(s):  
Spatial Distribution ◽  
Sampling Plans ◽  
Mesoplatys Ochroptera

Trophic interactions between three species of cereal aphid (Hemiptera: Aphididae) and spring wheat (Poaceae): implications for pest management

2007 ◽  
Vol 139 (6) ◽  
pp. 850-863 ◽  
Author(s):  
Samuel M. Migui ◽  
Robert J. Lamb
Keyword(s):  
Spring Wheat ◽  
Trophic Interactions ◽  
Plant Biomass ◽  
Rhopalosiphum Padi ◽  
Aphid Species ◽  
Economic Damage ◽  
Cereal Aphids ◽  
Cereal Aphid ◽  
Economic Thresholds ◽  
Specific Impact

AbstractThe susceptibilities of genetically diverse Canadian spring wheats, Triticum aestivum L. and Triticum durum Desf., to three aphid species, Rhopalosiphum padi (L.), Sitobion avenae (Fabricius), and Schizaphis graminum (Rondani), were investigated. Trophic interactions measured as changes in biomass of aphids and wheat plants were used to quantify levels of resistance, components of resistance, and impact of aphids on yield. Plants in field cages were infested with small numbers of aphids for 21 days at heading. These plants were usually more suitable for the development of S. avenae and S. graminum than of R. padi. Partial resistance, measured as seed production by infested plants as a proportion of that by a control, varied from 11% to 59% for different aphid species and wheat classes when all wheat plants were infested at the same stage. Cultivars within wheat classes responded similarly to each of the aphid species. None of the wheat cultivars showed agriculturally effective levels of antibiosis. The specific impact of each aphid species and wheat class varied from 5 to 15 mg of plant biomass lost for each milligram of biomass gained by the aphids. Canadian Western Red Spring wheat had a lower specific impact and therefore was more tolerant to aphids than the other two classes, but not tolerant enough to avoid economic damage at the aphid densities observed. Plants did not compensate for feeding damage after aphid feeding ceased, based on the higher specific impacts observed for mature plants than for plants that were heading. The interactions between aphids and plants show that current economic thresholds probably underestimate the damage caused by cereal aphids to Canadian spring wheat.

scholarly journals Spatial distribution pattern and sequential sampling plans for Bactrocera oleae (Gmelin) (Dip: Tephritidae) in olive orchards

2016 ◽  
Vol 48 (1) ◽  
pp. 23
Author(s):  
A. Arbab ◽  
F. Mirphakhar
Keyword(s):  
Spatial Distribution ◽  
Sample Size ◽  
Sequential Sampling ◽  
Bactrocera Oleae ◽  
Sampling Plans ◽  
Optimum Sample Size ◽  
Precision Level ◽  
The Individual ◽  
Optimum Sample ◽  
Basic Distribution

The distribution of adult and larvae <em>Bactrocera oleae</em> (Diptera: Tephritidae), a key pest of olive, was studied in olive orchards. The first objective was to analyze the dispersion of this insect on olive and the second was to develop sampling plans based on fixed levels of precision for estimating <em>B. oleae</em> populations. The Taylor’s power law and Iwao’s patchiness regression models were used to analyze the data. Our results document that Iwao’s patchiness provided a better description between variance and mean density. Taylor’s <em>b</em> and Iwao’s <em>β</em> were both significantly more than 1, indicating that adults and larvae had aggregated spatial distribution. This result was further supported by the calculated common <em>k</em> of 2.17 and 4.76 for adult and larvae, respectively. Iwao’s a for larvae was significantly less than 0, indicating that the basic distribution component of <em>B. oleae</em> is the individual insect. Optimal sample sizes for fixed precision levels of 0.10 and 0.25 were estimated with Iwao’s patchiness coefficients. The optimum sample size for adult and larvae fluctuated throughout the seasons and depended upon the fly density and desired level of precision. For adult, this generally ranged from 2 to 11 and 7 to 15 traps to achieve precision levels of 0.25 and 0.10, respectively. With respect to optimum sample size, the developed fixed-precision sequential sampling plans was suitable for estimating flies density at a precision level of D=0.25. Sampling plans, presented here, should be a tool for research on pest management decisions of <em>B. oleae</em>.

MONITORING OF ENTOMOСOMPLEXES OF SOFT SPRING WHEAT IN THE FOREST-STEPPE OF SAMARA AREA

2016 ◽  
Vol 1 (4) ◽  
pp. 3-9
Author(s):  
Каплин ◽  
Vladimir Kaplin
Keyword(s):  
Seedling Growth ◽  
Spring Wheat ◽  
Negative Impact ◽  
Stem Elongation ◽  
High Density ◽  
Forest Steppe ◽  
Cereal Aphids ◽  
Competitive Relations ◽  
Hippodamia Variegata ◽  
Pre Treatment

The purpose of research is creation of conditions for the formation of self-regulating entomocomplexes in agrocenoses with a significant competitive relations in the cultivation of spring wheat in the non-use of insecticides against pests. Insects was collected with an entomological net for 25-50 flaps in triple repeated in period of vegetation of wheat. In the conditions of the non-use of insecticides of entomokomplexes included insects-phytophagous which are potential vectors of viruses, phytoplasmas; suctorial and gnawing phytofagous; insects are developing inwardly wheat stems; entomophagous. Entomophagous regulating the density of phytophagous were represented by predators and parasites. In 2013-2016 Phyllotreta vittula, Oscinella pusilla, O. frit had a high density in the stage of seedling growth, Haplothrips tritici – in the stage of stem elongation of spring wheat. Against pests of seedlings in terms of their high density recommended for pre-treatment of seeds of spring wheat before sowing by system insecticide Cruiser, KC, without a negative impact on useful entomofauna of the agro-ecosystems. To the head emergence stage of spring wheat and the beginning of oviposition of Haplothrips tritici, its population was effectively reduced by Aeolothrips pascidutus. Development of cereal aphids was annualy kept Hippodamia variegata (Coccinellidae).

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