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United States Department of Agriculture

Agricultural Research Service

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2009 Annual Report

1a. Objectives (from AD-416)
1. Determine the mechanisms and rates of geographic dispersion of the Formosan Subterranean termite (FST) in Mississippi. 2. Develop and implement biologically-based cultural/ecological control technology against termites in urban environments and incorporate into an area-wide termite IPM project in Mississippi. 3. Provide an effective educational program in Mississippi to convey information on termite biology and current effective control measures.

1b. Approach (from AD-416)
1. In order to best understand the spread of FST in south Mississippi, mitochondrial DNA (mtDNA) sequence markers which identify maternal lineages will be used to track termite gene flow to infer possible routes of spread of FST in Mississippi. An approach of combining different markers with alternate modes of inheritance, such as nuclear and mtDNA markers can help us discern the maternal and paternal contributions to gene flow and population structure. 2. Our laboratory results showed that repellence and virulence of certain fungal conidia when applied to tree-based mulches will significantly reduce the suitability of these mulches as a habitat for FST. The performance of mulches treated with entomopathogenic fungi against FST foraging behavior, colony mortality, and product persistence will be investigated under field conditions. 3. The general approach will include dissemination of information to the public through newsletters, pamphlets, a website, workshops, and scheduled field days. Appropriate mobile displays with current information on the biology and control of FST will be developed for use in rural communities and in public schools and at meetings of local citizen groups in Mississippi.

3. Progress Report
Since the introduction of the Formosan subterranean termite (FST), to south Mississippi (MS), FST has significantly infested more counties over the past decade. Traditionally, it has been accepted that the movement of infested cellulosic wood products has led to the establishment and spread of FST in inland counties of this state from those port cities heavily infested by this termite species. However, this invasive structural pest could also be introduced into a new area with certain non-cellulosic commercial products as its transport medium. Our study provides new evidence that the spread of FST in MS is also attributed to commercial activities with some non-wood carriers (such as fiberglass fishing boat) moved from infested coastal areas. Molecular genetic analyses indicated that the genotype of a termite colony collected from a boat located in south MS, (originally purchased in New Orleans, Louisiana (LA) by the owner) has not been previously documented on the mainland of the U.S. Preliminary sequence alignment analysis exhibited that this termite sample from MS was genetically more similar to colonies documented in China. This study has been initiated to investigate the origin and infestation route of FST in southern MS. A total of 28 FST colonies were collected from 2004-08, including 21 colonies from MS, 6 colonies from LA, and 1 from China. Two genetically distinct types of FST were identified in MS, where the first (GA type) was identical to those reported previously in Georgia, Louisiana, Alabama, and other infested states in U.S.; and the 2nd (AT type) was identified in southeastern U.S. Sequence identity of the (AT type) of FST, with those reported mainly in China, provided evidence of at least 2 introductions of FST to the U.S. Previous studies concluded that the genetic diversity of FST was very low. One study reported 9 distinct gene types existed in FST in China, while 6 gene types had already been discovered in the U.S. However, based on our molecular survey, we suggested that the genetic diversity of FST might be even lower than that reported previously. The termites we surveyed in MS are potentially transported from the port cities in MS along the Gulf of Mexico due to the numerous infestations observed along transportation corridors via Interstate 59 in MS and Highway 11, as well as a railway parallel from New Orleans, LA, to Meridian, MS. The genetic diversity of FST in MS was expected to be higher than other inland states. However, besides a recently introduced colony from New Orleans, LA, with (AT type), 20 colonies collected in south MS turned out to have identical genotype of (GA type). Clearly, the invasion of FST to MS might be originated from the heavily infested port city of New Orleans, based on the fact of the proximity (~125 km) and the identity of gene types between New Orleans populations and MS populations of FST. Progress in this project is monitored through Annual FST Technical Committee Meetings, reports, regular meetings with cooperators, routine phone calls, and e-mail correspondence.

4. Accomplishments

Last Modified: 06/24/2017
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