Entomology Commons^™

Factors Affecting Insecticide-Induced Resurgence Of The Brown Planthopper, Nilaparvata Lugens On Rice, S. Chelliah, E. A. Heinrichs

Department of Entomology: Faculty Publications

Resurgence of the brown planthopper, Nilaparvata lugens (Stål) on rice was induced by applications of decamethrin, methyl parathion, and diazinon. Differential mortality of predators and hoppers did not appear to be the primary factor for resurgence. Hoppers appeared to be attracted to methyl parathion and decamethrin treated plants because of plant growth. Improved plant growth, however, did not compensate for the increased feeding of the insecticide-treated hopper population, and plants treated with resurgence-causing insecticides succumbed to feeding injury earlier than untreated plants. Population increases were due in part to stimulation of reproduction of the hopper, either by contact action of …

A Technique For Physiologically Age-Grading Female Stable Flies, Stomoxys Calcitrans (L.), P. J. Scholl

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

A method of dissection followed by staining was initiated to allow physiological age- grading based on ovarian development in order to more completely describe the physiological development of adult female stable flies [Stomoxys calcitrans (L. )]. The gonotrophic developmental continuum from a non-differentiated cell in teneral females to mature eggs at the time of oviposition was first arbitrarily divided into six stages by using distinct landmarks within the developing oocyte . Then, nulliparous, uniparous, and biparous+ females were differentiated on the basis of the presence or absence of stained follicular relics in the ovariole sheaths. The combination of the …

Alfalfa Insect Management Studies 1971-77, G. R. Manglitz, W. R. Kehr, D. L. Keith, J. M. Mueke, J. B. Campbell, R. L. Ogden, T. P. Miller

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Three tests in southwestern Nebraska during 1971 and 1972 evaluated insecticides against the army cutworm. Adult alfalfa weevils did not damage new second growth alfalfa in a small plot study during a 3-year period (1973-1975) at Gothenburg, NE. However, excellent control of larval alfalfa weevils was obtained. These results indicated a need to establish economic threshold levels for the alfalfa weevil in Nebraska to prevent unnecessary use of insecticides. Four tests to control the alfalfa weevil with registered insecticides verified the efficacy of these materials under Nebraska conditions. A series of tests conducted during 1975 at the Mead Field Laboratory …

Blueberry Progress Reports, Amr A. Ismail, David E. Yarborough, Delmont C. Emerson, Eric Hanson, John M. Smagula, Edward Mclaughlin, John Frett, G R. Benoit, W J. Grant, F L. Caruso, M G. Zuck, Steven B. Johnson, Simeon S. Leach, Howard Y. Forsythe Jr

Wild Blueberry Research Reports

The 1979 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Life Sciences and Agriculture Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include:

1. Cooperative Extension Activities

2. Plan of Work - FY 1980

3. Weed Control in Lowbush Blueberry Fields

4. Pruning of Blueberries

5. Integrated Management of Blueberry Fields

6. Physiology and Culture of the Lowbush Blueberry

7. Effect of Plant-Water Stress on "Lowbush" Blueberry Growth, Yield and Quality

8. Blueberry …

Honeydew Excretion Measurement Techniques For Determining Differential Feeding Activity Of Biotypes Of Nilaparvata Lugens On Rice Varieties, P. Paguia, M. D. Pathak, E. A. Heinrichs

Department of Entomology: Faculty Publications

Techniques to quantify the feeding activity of Nilaparvata lugens (Stål) on rice varieties as based on honeydew excretion are described, and their potential as a bioassay for biotype identification are discussed. Honeydew, excreted on filter paper, was stained with ninhydrin and quantified by measuring the area (mm²) or by weighing. Results were satisfactory but the methods were extremely tedious. Volumetric measurement of honeydew with micropipettes was less sensitive. The color intensity of one μliter honeydew streaked on filter paper and treated with 0.001% ninhydrin was determined with a Fujiox Densitometer. The method was relatively simple and rapid …