Population dynamics and management of potato leafhopper and other insect pests in forage systems

Abstract

This manuscript has been reproduced from the microfilm master. TJMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter &ce, while others may be from any type of computer printer.The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction.In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion.Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book.Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. UMI Dissertation OrganizationThe general introduction contains a brief discussion of the importance of alfalfa followed by the justification and objectives for this research. This is followed by the literature review that contains background information on potato leafliopper biology and ecology, potato leafhopper population dynamics, alternative alfalfa cropping systems research on alfalfa insect pests, and sampling methodology and management programs for potato leafhopper. Following the general introduction, there are four papers. The first paper assesses the population dynamics and diurnal activity of potato leafhopper in Iowa forages.The second paper discusses the effect of alfalfa and forage grass intercrops on alfalfa insect pests and associated natural enemy predator populations. A third paper describes the development of a sticky trap sampling technique for potato leafhopper adults in alfalfa using a series of comparative studies. The final paper describes the evaluation of grower-oriented sampling techniques and development of a management program for potato leafliopper in alfal&. A general conclusion follows the fourth paper. References cited in the general introduction are listed after the general conclusions. Inti-oductionAlfalfa, Medicago saliva L., is the world's most valuable cultivated forage crop (Grau et al. 1985) and the most important perennial forage crop in North America (Nfichaud et al. 1988, Pick andMueller 1989). Over 11 million ha of land in the United States (Melton et al. 1988) and 4-5 million ha of land in Canada (Goplen et al. 1980) are committed to alfalfa production. Alfalfa is predominantiy grown in the northeastern and northcentral regions of 2 the U.S. (Boken et al...

Enhancing biotic mortality of the potato leafhopper, Empoasca fabae

“…Delayed planting dates to manage E. fabae resulted in lower rates of hopperbum on potatoes . Alfalfa fields intercropped .vith non-host grasses, such as crabgrass and oats, show reduced densities of E. fabae , DeGooyer 1997. Roda et al (1997a, b) determined that alfalfa intercropped with smooth broomgrass, orchardgrass or timothy elicited emigration of E. fabae from alfalfa fields.…”