Date of Award
5-1995
Document Type
Thesis
Degree Name
Master of Arts (MA)
Department
Entomology
First Advisor
David J. Boethel
Abstract
The effects of southern green stink bug, Nezara viridula (L.), feeding on an indeterminate maturity group IV soybean cultivar, 'Ring Around 452', during different soybean reproductive growth stages were evaluated during 1993 and 1994. In 1993, southern green stink bug population levels of o, o. 5, 1, 3, 6, and 10 times the economic threshold in Louisiana (1 stink bug per 0.3 row m) were caged on soybeans for 7 d during the soybean growth stages of R3, R4, RS, R5.5, R6 and R7. In 1994, population levels of o, 0.5, 1, 1.5, and 3 times the economic threshold were evaluated during the soybean growth stages of R2, R3, R4, R5, R5.5, R6, and R7. In both studies, yield adjusted for stink bug damage discounts showed a decreasing trend with increasing stink bug population level when infestation occurred during RS. Percent pod fill decreased significantly with increasing stink bug population level when infestations occurred during R4 and RS. Weights of 100 randomly selected seeds and of 50 undamaged seeds increased significantly when plots were exposed to population levels greater than 1 stink bug per o. 3 row m during R4 and RS, indicating plant compensation for stink bug injury. Maturity of plants was significantly delayed by stink bug population levels greater than 1 stink bug per 0.3 row m when infestations occurred during R4 and RS. An increase in protein content and a decrease in oil content with increasing population level also was noted.
Regression analysis revealed a significant relationship between adjusted yield and southern green stink bug population level when infestation occurred during R4 and R5. Economic injury levels calculated over a range of control costs and crop values indicated that the current economic threshold in Louisiana is adequate for stink bug infestations occurring during R4, but may need adjustment for infestations occurring during other growth stages.
Recommended Citation
Lingren, Peter Scott, "Determination of a Dynamic Economic Threshold for the Southern Green Stink Bug, Nezara Viridula (L.), (Hemiptera: Pentatomidae) on an Indeterminate Soybean Cultivar" (1995). LSU Historical Dissertations and Theses. 8429.
https://repository.lsu.edu/gradschool_disstheses/8429