The Formosan subterranean termite, Coptotermes formosanus Shiraki, is responsible for over $1 billion in property damage, repairs, and control in the United States. Presently, control of this exotic pest depends mainly on chemical methods. There is an increasing interest in using natural products in pest control because of their low mammalian toxicity and environmental safety.
Chemical components of the roots of vetiver grass, Vetiveria zizanioides (L.) Nash, have shown to be effective repellents and toxicants to Formosan subterranean termites. Objectives of this research were to evaluate: 1) vetiver grass root growth and its oil distribution; 2) vetiver oil, nootkatone, and tetrahydronootkatone as wood treatments; and 3) understanding alate flight biology as preventative measures against Formosan subterranean termites.
The amount of vetiver oil present in the root system increased as root weight increased at each sampling date. At the final sampling period, mean root weight increased 520% from the previous sampling period. The highest vetiver root mulch to sand ratio tested was effective against Formosan subterranean termites by decreasing tunneling activity and increasing termite mortality, thus decreasing wood consumption.
In field and laboratory studies, wood samples treated with 5% nootkatone or 5% tetrahydronootkatone solutions showed good potential as possible wood treatment options. These studies indicated significantly less consumption of treated wood samples verses untreated controls. Significantly higher termite mortality was observed with treated wood samples as opposed to untreated controls in the laboratory evaluation.
Analysis of annual flights of the Formosan subterranean termite monitored for 16 years in New Orleans, Louisiana, indicated the timing of peak flights was non-random, suggesting a mechanism, either external or internal to the colony, triggers peak alate flights. No relationship was observed between any of the extrinsic factors tested in relation to the largest flight of the year. A degree day model was constructed to aid in predicting each years largest Formosan subterranean termite flight, which indicated peak flights did not occur before an average of 2611 heat units had accumulated.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-11042005-120721 |
| Date | 08 November 2005 |
| Creators | Nix, Karen Elizabeth |
| Contributors | Seth Johnson, Gregg Henderson, Roger A. Laine |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-11042005-120721/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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