Identifier

etd-04022013-101656

Degree

Doctor of Philosophy (PhD)

Department

Entomology

Document Type

Dissertation

Abstract

Rice is grown over an area of approximately 500,000 acres in Louisiana. The lepidopteran stem borer complex attacking rice in the southern U.S includes stalk borer Chilo plejadellus Zincken, sugarcane borer (SCB) Diatraea saccharalis (F.) and Mexican rice borer, Eoreuma loftini Dyar. With the increasing impact of stem borers in Louisiana, an urgent need exists to develop strategies for management. Currently, no IPM program is in place for stem borers in Louisiana rice and research has been initiated to develop an IPM program for these pests. The first objective of this research was focused on host plant resistance. For this objective, oviposition preference and larval performance of sugarcane borer on commonly grown rice cultivars in Louisiana were investigated. Results from the oviposition preference study revealed significant differences among cultivars. Overall females of D. saccharalis preferred ovipositing on the upper sides of the leaves of rice plants. In the performance study, three different measures of performance were used. Results from these studies revealed significant differences among varieties for these measures of performance. Results also revealed a strong correlation between different measures of performance as well as between performance and preference. Results from the compensation study revealed differences in compensatory response of same eight cultivars. In the silicon soil amendment study, a significant increase in silicon content of rice plants supplemented with calcium silicate was observed compared to the control plants. Soil Si amendment led to lower relative growth rates and reduced boring success of sugarcane borer larvae on. Studies were conducted to evaluate the efficacy of Dermacor seed treatment against sugarcane borer. Dermacor seed treatment was the most effective among different insecticides used in a field study and significantly increased larval mortality in lab and greenhouse experiments. These studies will help facilitate scouting for sugarcane borer in the field and improvement in insecticide timing. Potential exists for current use of these (moderately resistant) cultivars in IPM programs and as sources of resistance in breeding programs for stem borer resistance. Soil Si amendment and Dermacor seed treatments has the potential to fit into the IPM program.

Date

2013

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Stout, Michael

Included in

Entomology Commons

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