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Agriculture

Department of Entomology: Faculty Publications

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Full-Text Articles in Entomology

Insecticide-Induced Resurgence Of The Brown Planthopper, Nilaparvata Lugens, On Rice Varieties With Different Levels Of Resistance, W. H. Reissig, E. A. Heinrichs, S. L. Valencia Feb 1982

Insecticide-Induced Resurgence Of The Brown Planthopper, Nilaparvata Lugens, On Rice Varieties With Different Levels Of Resistance, W. H. Reissig, E. A. Heinrichs, S. L. Valencia

Department of Entomology: Faculty Publications

Three rice varieties, IR29, IR40, and IR42, which are, respectively, susceptible, moderately resistant, and resistant to Nilaparvata lugens Stål in the Philippines, were treated in the field with decamethrin, an insecticide known to cause resurgence. N. lugens populations increased to a significantly higher level in the treated plots than in untreated checks, but the degree of resurgence varied among varieties. The maximum population increases in the treated plots compared with the checks were ca. 74-, 50-, and 5-fold, respectively, for IR29, IR40, and IR42. Decamethrin was toxic to predators, and this reduction of natural enemies of N. lugens may …

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Ovicidal Activity Of Insecticides Against Planthoppers On Rice, E. A. Heinrichs, S. L. Valencia Jan 1981

Ovicidal Activity Of Insecticides Against Planthoppers On Rice, E. A. Heinrichs, S. L. Valencia

Department of Entomology: Faculty Publications

Insecticides were evaluated to determine their ovicidal activity against rice-feeding planthoppers, Nilaparvata lugens (Stål) and Sogatella furcifera Horvath. Carbofuran, methyl parathion, and triazophos were ovicidal as foliar sprays, and carbofuran, diazinon, metalkamate, and triazophos were ovicidal as paddy-water applications of granules in insectary studies. In a field study, only triazophos as a foliar spray provided significant ovicidal activity against N. lugens. Eggs of S. furcifera were more susceptible to insecticides than those of N. lugens. Ovicidal activity was dependent on age of egg at the time of insecticide application and on insecticide concentration.

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Factors Affecting Insecticide-Induced Resurgence Of The Brown Planthopper, Nilaparvata Lugens On Rice, S. Chelliah, E. A. Heinrichs Dec 1980

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 …

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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 Jan 1980

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 …

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Danos Causados À Soja Em Diferentes Níveis E Épocas De Infestação, Durante O Crescimento, Maria Helena M. Galileo, Elvis A. Heinrichs Jul 1979

Danos Causados À Soja Em Diferentes Níveis E Épocas De Infestação, Durante O Crescimento, Maria Helena M. Galileo, Elvis A. Heinrichs

Department of Entomology: Faculty Publications

Foram avaliados os danos causados à soja (Glycine max (L.) Merrill) por Edessa meditabunda (Fabricius, 1794), em diferentes níveis e épocas de infestação, usando-se gaiolas de campo, no ano agrícola 1973/74. Os níveis de dois, quatro, seis e dez insetos por gaiola, atuando do florescimento pleno até iniciar-se o enchimento da semente, bem como as infestações desde o florescimento pleno até o final da maturação fisiológica da semente, não reduziram o rendimento, o número de vagens e de sementes, o número de sementes por vagens e o peso médio da semente. Igualmente, a percentagem de sementes danificadas, em diferentes …

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Inseticidas Sistémicos E Endrin Aplicados No Controle De Elasmopalpus Lignosellus, E Seus Efeitos Sobre A Soja, Elvis A. Heinrichs Jan 1977

Inseticidas Sistémicos E Endrin Aplicados No Controle De Elasmopalpus Lignosellus, E Seus Efeitos Sobre A Soja, Elvis A. Heinrichs

Department of Entomology: Faculty Publications

Foi conduzido um experimento a campo, na Estação Experimental Agronômica da UFRGS, em Guaíba, RS, com o objetivo de determinar o efeito de vários inseticidas no controle da “broca-do-colo,” Elasmopalpus lignosellus (Zeller, 1848). Os tratamentos aplicados foram: 2 dosagens de Carbofuran no tratamento de sementes; 2 dosagens de Carbofuran, Aldicarb e Disulfoton granulado, aplicado no sulco na época do plantio; e 2 tratamentos de Endrin de 1 e 3 pulverizações no período de pós-emergência. Os resultados indicaram que apenas dois tratamentos com Endrin controlaram a broca. Rendimentos altos nos tratamentos com Endrin e Carbofuran granulado foram atribuídos ao controle da …

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A D-Vac Calibration Technique, K. P. Pruess, R. W. Whitmore Feb 1976

A D-Vac Calibration Technique, K. P. Pruess, R. W. Whitmore

Department of Entomology: Faculty Publications

Removal samples from an irrigated pasture were used as a calibration technique for the D-Vac. Plots 4 m2 were enclosed with a frame, and 1 initial and 3 removal samples were taken. Equations are given for computing the population and probability of collecting an insect. For leafhopper adults, leafhopper nymphs, Orius insidiosus (Say), and corn flea beetle, Chaetocnema pulicaria Melsheimer, calibrations (m2/linear m) were 0.405, 0.328, 0.272, and 0.490, respectively.

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Population Suppression Of Western Corn Rootworm By Adult Control With Ulv Malathion, K. P. Pruess, John F. Witkowski, Earle S. Raun Oct 1974

Population Suppression Of Western Corn Rootworm By Adult Control With Ulv Malathion, K. P. Pruess, John F. Witkowski, Earle S. Raun

Department of Entomology: Faculty Publications

ULV malathion (9.7 oz AI/acre) was applied by air to a 16 square-mile area during August of 1968, 1969, and 1970. Adult Diabrotica virgifera LeConte populations were reduced the following season by 39, 54, and 72%. No economic infestations occurred in the treated area the year following any application. Postspray migration of beetles was very limited, but adult migration during the peak emergence period the following season contributed to repopulation of the treated area. Migration and fecundity appear to be density-dependent factors which favor increases under low populations. Area suppression does not appear economically feasible, but adult control in individual …

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Tarnished And Alfalfa Plant Bugs In Alfalfa: Population Suppression With Ulv Malathion, K. P. Pruess Aug 1974

Tarnished And Alfalfa Plant Bugs In Alfalfa: Population Suppression With Ulv Malathion, K. P. Pruess

Department of Entomology: Faculty Publications

ULV malathion (9.7 oz AI/acre) was applied to a 16 mi2 area in August 1968, 1969, and 1970 for western corn rootworm, Diabrotica virgifera LeConte, adult control. Nontarget insects in alfalfa, also treated, were monitored. Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), was reduced 89–98%. Survival of eggs and adult migration resulted in rapid reinfestation of the treated area in 1969 and 1970; adult migration alone was important in 1968. Alfalfa plant bug, Adelphocoris lineolatus (Goeze), was reduced 96–98%. Repopulation following the 1969 and 1970 treatments was by development from eggs surviving the treatment. The 1969 treatment resulted …

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Response Of Soybean Insects To Foliar Applications Of A Chitin Synthesis Inhibitor Th 6040, S. G. Turnipseed, E. A. Heinrichs, R. F. P. Da Silva, J. W. Todd Jan 1974

Response Of Soybean Insects To Foliar Applications Of A Chitin Synthesis Inhibitor Th 6040, S. G. Turnipseed, E. A. Heinrichs, R. F. P. Da Silva, J. W. Todd

Department of Entomology: Faculty Publications

The activity of TH 6040, a chitin synthesis inhibitor, was determined against velvetbean caterpillar, Anticarsia gemmatalis Hübner, and other soybean defoliators in field tests in Georgia, South Carolina, and Brazil. Single applications at rates as low as 75 g AI/ha afforded adequate initial and excellent residual control of A. gemmatalis and some suppression of low populations of Plusia spp. Two applications at higher rates gave significant control of soybean looper, Pseudoplusia includens (Walker), and showed promise against green cloverworm, Plathypena scabra (F.), and Mexican bean beetle, Epilachna varivestis Mulsant. Populations of geocorids and nabids were lower in 1 test, possibly …

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Drift Of Terrestrial Arthropods In An Irrigation Canal Following A Wide-Area Application Of Ulv Malathion, Dewey Urbauer, K. P. Pruess Jan 1973

Drift Of Terrestrial Arthropods In An Irrigation Canal Following A Wide-Area Application Of Ulv Malathion, Dewey Urbauer, K. P. Pruess

Department of Entomology: Faculty Publications

Numbers of arthropods drifting in an irrigation canal were recorded at 30-min intervals during and after an upstream application of ULV malathion. Flower-visiting and parasitic Hymenoptera were the first insects to increase; a bimodal drift pattern resulted from an interruption in the spray application. Diptera exhibited a delayed response but the numbers collected, especially Paracantha culta (Wiedemann), suggest high susceptibility. Ants occurred in large numbers over a long period, but mortality was probably low. Miridae and Cicadellidae were probably more susceptible than Orthoptera and adult Odonata but had similar delayed drift patterns. Tetragnathidae were the most, and Thomiscidae the least, …

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Western Corn Rootworm Egg Distribution And Adult Emergence Under Two Corn Tillage Systems, K. P. Pruess, G. T. Weekman, B. R. Somerhalder Oct 1968

Western Corn Rootworm Egg Distribution And Adult Emergence Under Two Corn Tillage Systems, K. P. Pruess, G. T. Weekman, B. R. Somerhalder

Department of Entomology: Faculty Publications

Under a conventional plowing system, eggs of Diabrotica virgifera LeConte were more uniformly deposited in the top 6 inches of the soil profile than under a reduced strip-tillage system which resulted in heaviest egg deposition in the furrow or ridge. Equal numbers of eggs were deposited in both systems. After corn was planted, more eggs occurred in the seedling zone in conventionally planted corn; in till-plant corn, eggs were removed from the seed row, and eggs concentrated in the furrow were covered with additional soil. Adult emergence was 5–10 days later in till-plant corn than in the conventional tillage system.

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Distribution Of Army Cutworm Larvae In Wheat And Barley Fields, K. P. Pruess Apr 1961

Distribution Of Army Cutworm Larvae In Wheat And Barley Fields, K. P. Pruess

Department of Entomology: Faculty Publications

Populations of the army cutworm, Chorizagrotis auxiliaris (Grote), tended to be higher in winter barley than winter wheat planted side by side in the same field. Highest populations occurred in barley within 30 feet of the adjoining wheat. Distribution of larvae in linear 1-foot samples agreed closely with the Poisson. Practical application of these results are discussed.

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Effects Of Moisture On The Clover Root Borer And Red Clover Yields, K. P. Pruess, C. R. Weaver Dec 1959

Effects Of Moisture On The Clover Root Borer And Red Clover Yields, K. P. Pruess, C. R. Weaver

Department of Entomology: Faculty Publications

Rainfall and populations of the clover root borer, Hylastinus obscurus (Marsham), were artificially controlled in pots of red clover grown under shelters in the field. Populations of clover root borer were higher under dry conditions. Although yield losses were high in borer-infested pots, yield reductions were no greater under dry than under wet conditions.

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Effect Of Host Condition On The Clover Root Borer, K. P. Pruess Dec 1958

Effect Of Host Condition On The Clover Root Borer, K. P. Pruess

Department of Entomology: Faculty Publications

Oviposition by the clover root borer, Hylastinus obscurus (Marsham), is completed earlier in weakened than in vigorous plants, but development is more rapid in vigorous or lightly infested roots. High populations occurring early in the season result in plant mortality with subsequently slowed borer development.

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Further Tests Of Band Placement Of Insecticides For Clover Root Borer Control, C. R. Weaver, K. P. Pruess, J. L. Parsons Jun 1957

Further Tests Of Band Placement Of Insecticides For Clover Root Borer Control, C. R. Weaver, K. P. Pruess, J. L. Parsons

Department of Entomology: Faculty Publications

Weaver & Haynes (1955) described a method of placement of insecticides in bands under red clover seed that achieved control of the clover root borer, Hylastinus obscurus (Marsh.). Band placement was as effective at 0.75 pound of toxicant per acre as broadcast treatments at 1 pound or more as reported by Gyrisco et al. (1954) and App & Everly (1950). Since the 1951–53 tests were carried out in one location on small plots and applied by a farm crew experienced in experimental procedures, it was desired to test the band placement method more extensively. Tests in 1954–56 were conducted at …

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New Elementary Agriculture For Rural And Graded Schools, Charles E. Bessey, Lawrence Bruner, G. D. Swezey Jan 1903

New Elementary Agriculture For Rural And Graded Schools, Charles E. Bessey, Lawrence Bruner, G. D. Swezey

Department of Entomology: Faculty Publications

Nebraska is an agricultural state. The products of her soil are the basis of her industries and her prosperity. The children of our great state of Nebraska should be familiar with our crops, our grains and grasses, our flowers and fruits, our trees and shrubs and weeds, our domestic animals and birds and insects. Our children should have a practical knowledge of the management of a farm, of the composition of the soil, and of the adaptability of the farm and its soil for the cultivation of certain plants and the counter effect of such plant growth upon the soil. …

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A Preliminary Introduction To The Study Of Entomology, Lawrence Bruner Jan 1894

A Preliminary Introduction To The Study Of Entomology, Lawrence Bruner

Department of Entomology: Faculty Publications

This book has been prepared for the purpose of partially supplying a demand that seems to exist here in the West for an elementary work on entomology such as can be used in the public schools and on the farm. It is not an original production, but comprises notes from many sources as they have been gathered by the writer and presented from time to time in talks to his classes in the University of Nebraska and before audiences at farmers' institutes throughout the state. The chapters on remedies and on apple and small grain insects have been compiled and …

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Insect Enemies Of The Small Grains, Lawrence Bruner Jan 1893

Insect Enemies Of The Small Grains, Lawrence Bruner

Department of Entomology: Faculty Publications

Although "corn is king" in Nebraska, our crops of small grains are not insignificant. The insect enemies of wheat, oats, barley, and rye therefore demand our attention nearly or quite as much as do those which attack corn. Accordingly, during the past year much time has been given to the study of this class of insect pests. While many of the species are identical for the different crops, the nature of the plants themselves being unlike, it necessarily follows that the mode of attack among these enemies must vary somewhat in each case. This being true, some pains has been …

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