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Department of Entomology: Faculty Publications

Series

1982

Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

Damage Potential Of Adult And Larval Southern Corn Billbugs (Coleoptera: Curculionidae) On Field Corn In Eastern North Carolina, Robert J. Wright, J. W. Van Duyn, J. R. Bradley Jr. Oct 1982

Damage Potential Of Adult And Larval Southern Corn Billbugs (Coleoptera: Curculionidae) On Field Corn In Eastern North Carolina, Robert J. Wright, J. W. Van Duyn, J. R. Bradley Jr.

Department of Entomology: Faculty Publications

Adult and larval damage potential of the southern corn billbug (SCB), Sphenophorus callosus (Olivier), was studied in small-plot enclosures and in commercial cornfields in eastern North Carolina from 1978 to 1980. In small-plot studies, corn at the two- and four-leaf stages showed damage by adult SCB at several insect densities, but more mature corn was not visibly damaged. Female SCB caused more damage than male SCB on three- to four-leaf stage corn. Damage by females tended to result in dead terminals, whereas feeding by males more often resulted in holes in the leaves. In small-plot studies, average plant height per …

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Host Range Of Southern Corn Billbug (Coleoptera: Curculionidae) Adults And Larvae, Robert J. Wright, J. W. Van Duyn, J. R. Bradley Jr. Aug 1982

Host Range Of Southern Corn Billbug (Coleoptera: Curculionidae) Adults And Larvae, Robert J. Wright, J. W. Van Duyn, J. R. Bradley Jr.

Department of Entomology: Faculty Publications

Host range of the southern corn billbug, (SCB), Sphenophorus callosus (Olivier) (Coleoptera: Curculionidae), was tested with 14 crop and weed species by artificially infesting plants with SCB adults and eggs; field observations were also made. Of 14 species tested, only corn, Zea mays L., and yellow nutsedge, Cyperus esculentus L., allowed completion of larval development, although adults fed on a wider variety of plants. Scirpus cyperinusI, (L.) Kunth (Cyperaceae) was found to be a new SCB larval host from field observations. Overwintered SCB adults were fed sections of greenhouse-grown corn and four weed species in the laboratory. Survival was highest …

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Tolerance Of The Rice Variety Triveni To The Brown Planthopper, Nilaparvata Lugens, D. T. Ho, E. A. Heinrichs, F. Medrano Jun 1982

Tolerance Of The Rice Variety Triveni To The Brown Planthopper, Nilaparvata Lugens, D. T. Ho, E. A. Heinrichs, F. Medrano

Department of Entomology: Faculty Publications

Seedling screening and survival and population growth studies on 30-day-old plants indicated similar degrees of susceptibility on Taichung Native 1 (TN1) and Triveni rice to Nilaparvata lugens (Homoptera: Dilphacidae). However, studies in the screenhouse and field indicated that at both the vegetative and mature stage, Triveni possesses tolerance to insect damage, expressed as the ability to survive and produce a higher percentage of productive tillers than TN1 at similar N. lugens populations. Yield reduction caused by feeding of N. lugens was ca. 40% when infested with 400 N. lugens on 35-, 50-, or 75-day-old plants, whereas it was almost 100% …

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Effects Of Insecticides On Nilaparvata Lugens And Its Predators: Spiders, Microvelia Atrolineata, And Cyrtorhinus Lividipennis, W. H. Reissig, E. A. Heinrichs, S. L. Valencia Feb 1982

Effects Of Insecticides On Nilaparvata Lugens And Its Predators: Spiders, Microvelia Atrolineata, And Cyrtorhinus Lividipennis, W. H. Reissig, E. A. Heinrichs, S. L. Valencia

Department of Entomology: Faculty Publications

Thirty-five insecticides used on rice in Asia were tested in the field against Nilaparvata lugens. The most important predators of the pest, Cyrtorhinus lividipennis, Microvelia atrolineata, and predacious spiders, Lycosa pseudoannulata, Tetragnatha, and Araneus species, were also monitored in the test plots. Ten insecticides significantly reduced numbers of N. lugens, but propoxur and ethylan gave the most consistent and effective control. Most insecticides did not significantly reduce populations of spiders and M. atrolineata compared with untreated checks, but they did reduce numbers of C. lividipennis. Fifteen treatments caused resurgence of N. lugens, …

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Resurgence Of Nilaparvata Lugens (Stål) Populations As Influenced By Method And Timing Of Insecticide Applications In Lowland Rice, E. A. Heinrichs, G. B. Aquino, S. Chelliah, S. L. Valencia, W. H. Reissig Feb 1982

Resurgence Of Nilaparvata Lugens (Stål) Populations As Influenced By Method And Timing Of Insecticide Applications In Lowland Rice, E. A. Heinrichs, G. B. Aquino, S. Chelliah, S. L. Valencia, W. H. Reissig

Department of Entomology: Faculty Publications

Resurgence of Nilaparvata lugens (Stål) after insecticide application is a common phenomenon in rice in South and Southeast Asia. Among other insecticides inducing resurgence, carbofuran, decamethrin, and methyl parathion were selected for this study. Of the various methods of carbofuran application tested, foliar sprays were most active in inducing resurgence. Extent of resurgence was highly influenced by time of insecticide application. Sprays of methyl parathion and decamethrin applied 50 and 65 days after transplanting (DT) induced resurgence in the third generation of N. lugens at ca. 90 DT, whereas earlier applications had little effect. The cause(s) for resurgence was not …

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Selection Of Biotype Populations 2 And 3 Of Nilaparvata Lugens By Exposure To Resistant Rice Varieties, P. K. Pathak, E. A. Heinrichs Feb 1982

Selection Of Biotype Populations 2 And 3 Of Nilaparvata Lugens By Exposure To Resistant Rice Varieties, P. K. Pathak, E. A. Heinrichs

Department of Entomology: Faculty Publications

The release of an insect pest-resistant variety and subsequent adaptation of the insect species to that variety through the process of biotype selection has occurred on many cultivated crops. The present study was designed to obtain detailed information on some of the processes involved in the selection of biotypes of Nilaparvata lugens (Stål) on two rice varieties with different major genes for resistance. The N. lugens population selected for the study, which had originally been collected in the field and reared on a susceptible variety for 12 years (ca. 140 generations), initially had a low survival on the resistant rice …

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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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Resistance To The Rice Gall Midge Orseolia Oryzae In Rice, E. A. Heinrichs Jan 1982

Resistance To The Rice Gall Midge Orseolia Oryzae In Rice, E. A. Heinrichs

Department of Entomology: Faculty Publications

Orseolia oryzae, the rice gall midge is a major pest of rice in many areas of tropical Asia and is becoming an important pest in Africa. A chronological review of the progress made in various national programs on varietal resistance, sources of resistance and breeding for resistance is given. Many resistant varieties have been identified and have been utilized in breeding programs to develop high yielding varieties with multiple resistance to the gall midge and other insect pests and diseases. Mechanisms and inheritance of resistance in rice varieties are discussed. Rice varieties resistant in various countries and sources of resistance …

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A Bibliography Of Varietal Resistance To The Rice Gall Midge, Orseolia Oryzae (Wood-Mason), P. K. Pathak, E. A. Heinrichs Jan 1982

A Bibliography Of Varietal Resistance To The Rice Gall Midge, Orseolia Oryzae (Wood-Mason), P. K. Pathak, E. A. Heinrichs

Department of Entomology: Faculty Publications

This bibliography contains 330 published and unpublished references for the period 1881-1981. References are arranged alphabetically by author and are also classified by country and by subjects (mass rearing, screening, evaluation and utilization of resistant varieties, breeding for and inheritance of resistance, and biotype variation). Tables list resistant varieties identified, varietal sources used in breeding programs, varieties which have been released for cultivation by farmers and biotype classification.

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