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Integrated Pest Management—Stalk Borer Ecology And Pest Management Options In Corn And Soybean, Marlin E. Rice, Larry P. Pedigo Mar 1997

Integrated Pest Management—Stalk Borer Ecology And Pest Management Options In Corn And Soybean, Marlin E. Rice, Larry P. Pedigo

Agriculture and Environment Extension Publications

Stalk borers can heavily infest crops that are adjacent to grass terraces, fence lines, or grass waterways and cornfields. Cultural and chemical management techniques are discussed.


Evaluation Of Natural Enemies Of The European Corn Borer, Ostrinia Nubilalis (Lepidoptera: Pyralidae) , Mpho Wycliffe Phoofolo Jan 1997

Evaluation Of Natural Enemies Of The European Corn Borer, Ostrinia Nubilalis (Lepidoptera: Pyralidae) , Mpho Wycliffe Phoofolo

Retrospective Theses and Dissertations

The overall objective of this dissertation was to evaluate, both directly and indirectly, the natural enemies of the European corn borer (ECB). The direct evaluation component consisted of two parts: (1) Assessment of the level of naturally occurring mortality of the ECB and evaluation of the impact of biotic and abiotic factors that cause this mortality, and (2) Quantitative evaluation of the impact of augmentative releases of Trichogramma brassicae, a parasitoid of the ECB eggs, on reducing larval densities and damage on corn plants. The indirect laboratory-based evaluation, addressed two factors that affect the efficacy of natural enemies: prey suitability ...


Population Dynamics And Management Of Potato Leafhopper And Other Insect Pests In Forage Systems , Todd Allen Degooyer Jan 1997

Population Dynamics And Management Of Potato Leafhopper And Other Insect Pests In Forage Systems , Todd Allen Degooyer

Retrospective Theses and Dissertations

The potato leafhopper, Empoasca fabae (Harris) (Homoptera: Cicadellidae) is a major insect pest of alfalfa in the north central and northeastern United States. Studies were conducted from 1994 through 1996 to better understand the population dynamics of potato leafhopper in Iowa, as well as improve sampling and management of this and other alfalfa pests. The specific objectives of this dissertation were to (1) understand the population dynamics and diurnal activity of potato leafhopper in Iowa forage systems; (2) determine the effect of alfalfa-forage grass intercrops on potato leafhopper, as well as other alfalfa insect pests and predators; (3) assess the ...


Insecticidal Properties Of Monoterpenoids And Their Derivatives As A New Natural Means Of Crop Protection , Sang Kyun Lee Jan 1997

Insecticidal Properties Of Monoterpenoids And Their Derivatives As A New Natural Means Of Crop Protection , Sang Kyun Lee

Retrospective Theses and Dissertations

The overall objectives are to determine the feasibility of using natural monoterpenoids as alternatives to the conventional insecticides and to investigate the biological properties of monoterpenoids and derivatives. The evaluations for biological properties of monoterpenoid compounds were undertaken against economically important pest species with several systematic bioassays and parameters showing biological activities;A wide range of monoterpenoids showed acute topical toxicity against insects tested and most monoterpenoids were lethal to the mite at high concentrations. Soil bioassays revealed that monoterpenoids had larvicidal activity against the corn rootworm. Several monoterpenoids also effectively protected corn plants from corn rootworm attack under greenhouse ...


Relationship Between Poplar Leaf Chemicals And Cottonwood Leaf Beetle Adult Feeding Preferences , Sisi Lin Jan 1997

Relationship Between Poplar Leaf Chemicals And Cottonwood Leaf Beetle Adult Feeding Preferences , Sisi Lin

Retrospective Theses and Dissertations

The cottonwood leaf beetle, Chrysomela scripta F. (Coleoptera: Chrysomelidae), is considered to be one of the most serious defoliators of Populus plantations in North America. This research was conducted to understand the relationship between poplar leaf secondary chemicals and adult beetle feeding preferences;Leaf surface chemicals from a cottonwood leaf beetle-preferred poplar clone, 'Eugenei' (Populus deltoides x Populus nigra), was found to induce feeding in the adult cottonwood leaf beetle. The feeding stimulants were isolated and identified as n-beheryl alcohol (C22), n-lignoceryl alcohol (C24), n-hexacosanol (C26), n-octacosanol (C28), n-triacontanol (C30), and [alpha]-tocopherylquinone ([alpha]-TQ), (2-(3-hydroxy-3,7,11,15-tetramethyl-hexadecyl ...


The Colonization Of Corn, Zea Mays L., By The Entomopathogenic Fungus, Beauveria Bassiana (Balsamo) Vuillemin , Bruce Lamoine Wagner Jan 1997

The Colonization Of Corn, Zea Mays L., By The Entomopathogenic Fungus, Beauveria Bassiana (Balsamo) Vuillemin , Bruce Lamoine Wagner

Retrospective Theses and Dissertations

The ubiquitous entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina: Hyphomycetes) has been extensively investigated to suppress populations of several insect species worldwide. In studies investigating the response of inbred maize lines to plant pathogenic fungi, B. bassiana was isolated from the pith of plants. Subsequent field studies have shown that B. bassiana placed in or on maize plants formed an endophytic relationship, persisted for greater than 90 days and remained virulent to insects throughout the growing season. Even though these field studies demonstrated the potential insecticidal use of this relationship, the manner in which B. bassiana colonizes Zea mays L ...


Sample Distance And Observer Characteristic Effects On Corn Rootworm Beetles Counts In Corn And Resource Allocation Optimization In Corn Rootworm Insecticide Trials , James Joel Mcnutt Jan 1997

Sample Distance And Observer Characteristic Effects On Corn Rootworm Beetles Counts In Corn And Resource Allocation Optimization In Corn Rootworm Insecticide Trials , James Joel Mcnutt

Retrospective Theses and Dissertations

Counting adult rootworms has not yet met with widespread adoption by Iowa growers. It is more economical to always treat with an insecticide than to scout and treat when the rootworm population reaches economic levels. However, it is estimated that the majority of insecticide applications are not warranted. This inconsistency results from the cost and variability of scouting resulting in unrealistic thresholds;Establishing the existence or non-existence of an edge effect can reduce the error and/or cost of scouting. If there are differences at the edges, then the establishment of the sample boundaries will reduce sampling error. Sampling as ...


Biological Control Of The Tarnished Plant Bug In Iowa, John J. Obrycki, Gail R. Nonnecke Jan 1997

Biological Control Of The Tarnished Plant Bug In Iowa, John J. Obrycki, Gail R. Nonnecke

Leopold Center Completed Grant Reports

TPB, the tarnished plant bug (Lygus lineolarisj, attacks strawberries in Iowa and the Midwest. The egg parasitoid (Anaphes \o\e) has been observed to parasitize TPB in several crops in the western United States, but its activities have not been studied in strawberries in the Midwest. Under laboratory conditions, it was determined that A. iole will parasitize TPB eggs in strawberry stems. Releases of A. iole females in large field cages containing low densities of TPB eggs did not result in successful parasitization.


Natural Enemies Of The Cottonwood Leaf Beetle In Central Iowa, Jennifer Ann Jarrard Jan 1997

Natural Enemies Of The Cottonwood Leaf Beetle In Central Iowa, Jennifer Ann Jarrard

Retrospective Theses and Dissertations

No abstract provided.


Building In Integrated Pest Management Network In Cooperation With Iowa Fruit And Vegetable Growers, Mark L. Gleason, Donald R. Lewis, Forrest W. Nutter Jr., Gail R. Nonnecke, Paul Lasley, Steven C. Padgitt, Eldon R. Everhart, Gary Peterson, Naomi Maahs Jan 1997

Building In Integrated Pest Management Network In Cooperation With Iowa Fruit And Vegetable Growers, Mark L. Gleason, Donald R. Lewis, Forrest W. Nutter Jr., Gail R. Nonnecke, Paul Lasley, Steven C. Padgitt, Eldon R. Everhart, Gary Peterson, Naomi Maahs

Leopold Center Completed Grant Reports

Fifty-one commercial growers of apples, strawberries, tomatoes, and/or watermelons cooperated with Iowa State University (ISU) Extension specialists in a three-year program to evaluate IPM control techniques. Scouts and growers monitored pest infestations and diseases such as codling moth on apples, tarnished plant bugs on strawberries, and anthracnose on tomatoes and melons. Growers sprayed only when pest populations or disease risk values reached levels capable of doing crop damage. Weather conditions were monitored for periods favorable to pest outbreaks. On average, ISU researchers estimate that growers applied from 25 to 55 percent fewer insecticide and fungicide sprays (depending on the ...


The Cereal Leaf Beetle In Iowa Oats: Research And Education Program For Biological Control And Sustainable Management Practices, John J. Obrycki, Marlin E. Rice Jan 1997

The Cereal Leaf Beetle In Iowa Oats: Research And Education Program For Biological Control And Sustainable Management Practices, John J. Obrycki, Marlin E. Rice

Leopold Center Completed Grant Reports

The cereal leaf beetle, (Oulema melanopusj, a serious insect pest of small grains, including oats, was detected in the eastern half of Iowa in the early 1990s. Iowa's five leading counties for oat production are located in northeastern Iowa, and field surveys were conducted in this area to document Entomology the levels of cereal leaf beetle infestations, potential impact on production, and the presence of natural enemies. Findings showed that current cereal leaf beetle numbers are too low to cause economic damage and no compelling need exists to establish a management program aimed against this particular pest


Effects On Transgenic Thuringiensis On European Corn Borer Natural Enemies And Non-Target Lepidopteran Pests, Marlin E. Rice, John J. Obrycki, Leslie C. Lewis, Clinton D. Pilcher Jan 1997

Effects On Transgenic Thuringiensis On European Corn Borer Natural Enemies And Non-Target Lepidopteran Pests, Marlin E. Rice, John J. Obrycki, Leslie C. Lewis, Clinton D. Pilcher

Leopold Center Completed Grant Reports

Field corn, genetically engineered to produce a protein derived from Bacillus thuringiensis, was evaluated for its effects on larvae of black cutworm, stalk borer, armyworm, and corn earworm. No Btcorn effects were observed on larval survival, pupal weight, or days to adult emergence for black cutworm or stalk borer. Armyworms reared on Bt leaf extract were lighter-weight, delayed in development, and showed diminished survival rates. Corn earworm showed reduced survival and delays in development. In field tests of Bt and non-Bt corn, there were no differences between the two varieties in damage from black cutworm. Stalk borer caused less leaf ...