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Suppression Of Colorado Potato Beetle, Leptinotarsa Decemlineata (Say), (Coleoptera: Chrysomelidae) Populations With Antifeedant Fungicides, J. Daniel Hare, Patrick A. Logan, Robert Wright
Suppression Of Colorado Potato Beetle, Leptinotarsa Decemlineata (Say), (Coleoptera: Chrysomelidae) Populations With Antifeedant Fungicides, J. Daniel Hare, Patrick A. Logan, Robert Wright
Department of Entomology: Faculty Publications
Laboratory, small-field plot, and commercial-scale experiments were completed, using Connecticut, Rhode Island, and New York Colorado potato beetle, (CPB) Leptinotarsa decemlineata (Say), populations to determine if "antifeedant fungicides" might reduce the suitability of potato for CPB while simultaneously protecting potato from early and late blight. In the laboratory. fungicides formulated from triphenyltin hydroxide (TPTH) or Cu(OH), reduced CPB feeding 95 and 61%. In small-field plots, CPB larval densities were significantly reduced where TPTH and Cu(OH)2 were used regularly. In commercial-scale experiments, L. decemlineata populations were significantly reduced and required fewer insecticide applications for acceptable control where TPTH was used …
Factors Influencing Adult Emergence From Diapausing Sorghum Midge, Contarinia Sorghicola (Diptera: Cecidomyiidae, Frederick P. Baxendale, G. L. Teetes
Factors Influencing Adult Emergence From Diapausing Sorghum Midge, Contarinia Sorghicola (Diptera: Cecidomyiidae, Frederick P. Baxendale, G. L. Teetes
Department of Entomology: Faculty Publications
Sorghum midge, Contarinia sorghicola (Coquillett) diapause was terminated in the laboratory, and factors affecting adult emergence from diapausing larvae were investigated. Temperatures in the range from 20 to 30°C were optimum for diapause termination and adult emergence. Diapausing larvae exposed to moist conditions at 30°C began to emerge as adults after 12 days of incubation. Based on adult emergence rates per day, an emergence threshold temperature was estimated to be 14.8°C. Exposure to 12 to 13 days of continuous moisture at 30°C was essential for diapause termination and adult emergence. Moisture acted to initiate diapause termination, but diapausing larvae were …
Thermal Requirements For Emergence Of Overwintered Sorghum Midge (Diptera: Cecidomyiidae), Frederick P. Baxendale, G. L. Teetes
Thermal Requirements For Emergence Of Overwintered Sorghum Midge (Diptera: Cecidomyiidae), Frederick P. Baxendale, G. L. Teetes
Department of Entomology: Faculty Publications
Emergence of overwintered sorghum midges, Contarinia sorghicola (Coquillett), was monitored during 1979, 1980, and 1981. Differences in emergence times and distributions among years was a function of soil temperature and rainfall. A heat unit accumulation model incorporating a rainfall adjustment factor was developed which described adult emergence in the spring. Adult midges initiated emergence after accumulating 431 centigrade heat units (based on mean daily to-cm soil temperatures starting 1 April) above a threshold temperature of 14.8°C, whereas, 679 and 977 heat units were required for 50 and 95% emergence, respectively. Sorghum midges that overwintered in johnsongrass spikelets emerged after similar …
Dispersal, Flight, And Diurnal Activity Patterns Of Adult Southern Corn Billbugs (Coleoptera: Curculionidae), Robert J. Wright, J. W. Van Duyn, J. R. Bradley Jr.
Dispersal, Flight, And Diurnal Activity Patterns Of Adult Southern Corn Billbugs (Coleoptera: Curculionidae), Robert J. Wright, J. W. Van Duyn, J. R. Bradley Jr.
Department of Entomology: Faculty Publications
Dispersal into cornfields, flight, and diurnal activity patterns of the adult southern com billbug (SCB), Sphenophorus callosus (Olivier), were studied in eastern North Carolina during 1979 and 1980. Com plant damage (an index of SCB density) in fields with different cropping histories was initially concentrated either on the field edge next to last year's corn in rotated fields, or the edge next to the overwintering site in nonrotated fields. Although damage patterns and trapping studies suggested that SCB dispersal into fields was primarily by walking, SCB are capable of strong flight. Weevils of both the overwintered and summer generations were …
Day-Degree Methods For Pest Management, Kenneth P. Pruess
Day-Degree Methods For Pest Management, Kenneth P. Pruess
Department of Entomology: Faculty Publications
Recommendations are made for reporting day-degree methods which may have practical applications. Standardized thresholds (40, 50, and 60°F, or 5, 10, and 15°C) should be used. Day-degrees may be either sine wave approximations or exact units determined by instrumentation. Methods are proposed for converting current day-degree models to standardized thresholds and, ultimately, to actual day-degrees.
Biology And Seasonal Abundance Of Hymenopterous Parasitoids Of Sorghum Midge (Diptera: Cecidomyiidae), Frederick P. Baxendale, C. L. Lippincott, G. L. Teetes
Biology And Seasonal Abundance Of Hymenopterous Parasitoids Of Sorghum Midge (Diptera: Cecidomyiidae), Frederick P. Baxendale, C. L. Lippincott, G. L. Teetes
Department of Entomology: Faculty Publications
Four hymenopterous parasitoids of the sorghum midge, Contarinia sorghicola (Coquillet), were found in Burleson County, Texas: Eupelmus popa Girault, Tetrastichus near venustus Gahan, Tetrastichus near blastophagi (Ashmead), and Aprostocetus diplosidis Crawford. E. popa and A. diplosidis were ectoparasitic on the midge host in sorghum spikelets, while T. near venustus fed both externally and internally. Members of the parasitoid complex oviposited and developed to adults in spikelets containing 1- to 18-day-old immature midges, which corresponded to larval and pupal stages of midges. Most parasitoids developed from midges parasitized as mid-stage larvae. Developmental time from egg to adult emergence ranged from 7 …