Formosan Termite Information for Indiana

Timothy Gibb, Insect Diagnostician, Purdue University

We have stated before the dangers in believing everything that is posted on the Internet.  Recently, the following story has caused quite a stir and resulted in many questions to our laboratory.  It comes from an unknown source, making it very difficult to track down and correct at the origin.  The story goes as follows:

If you use mulch around your house be very careful about buying mulch this year. After the Hurricane in New Orleans many trees were blown over. These trees were then turned into mulch and the state is tryingto get rid of tons and tons of this mulch to any state or company who will come and haul it away. So it will be showing up in Home Depot and Lowes at dirt cheap prices with one huge problem; Formosan Termites will be the bonus in many of those bags. New Orleans is one of the few areas in the country were the Formosan Termites has gotten a strong hold and most of the trees blown down were already badly infested with those termites. Now we may have the worst case of transporting a problem to all parts of the country that we have ever had. These termites can eat a house in no time at all and we have no good control against them, so tell your friends that own homes to avoid cheap mulch and know were it came from.

Specialists at Purdue University DO NOT believe that Formosan termites will be transported into our area via mulch from Hurricane Katrina ravaged areas. While we have been cautioning people about transporting firewood from one region to another due to the potential spread of emerald ash borer, we have never warned customers purchasing mulch to be concerned about termites.

The story above neglects to mention the following very important facts about Formosan termites relating to their unlikely spread to Indiana via mulch from the gulf coast. 

1)  Very strict laws regulate the movement of wood products from infested regions.  Rest assured that governmental agencies in the areas affected by Hurricane Katrina are monitoring the movement of wood products very closely.  Contaminated products will not be allowed to be legally moved or sold to other parts of the Country

2)  Although it is true that Formosan termites may be successfully translocated if their termite nests are transported, this can ONLY occur if large solid pieces of wood are moved.  A nest is, by necessity, quite large and consists of multi chambers holding the queen and all of the immature termites while they develop.  Only a relatively large section of wood, such as a tree or a railroad tie may contain a termite nest.  Sawdust or mulch will not.

3)  The termite social system is complex and must be intact for the  survival and reproduction of the termite colony.  Workers and soldiers are castes in the colony that do the foraging and provide protection for the colony.  While very common and important to the colony, these individuals cannot reproduce and in fact, are unlikely to even survive more than just a few days away from their colony.  Inadvertent transfer of worker termites, even if they were able to withstand the chipping shredding, packaging and transport of mulch materials, would not constitute a threat of infestation.

4) For those of us that live in the State of Indiana it is important to know that Formosan termites have not been known to survive north of 35° N latitude because of the cold temperatures.  Formosans are tropical termites that live in very warm, moist areas only.

The questions that Hoosiers should be asking because of the story above relate to the termites already within our state.  The most problematic termite in our area is called a Subterranean termite. In nature, their role as decomposers of dead and fallen trees is very valuable. However, because they do not differentiate between wood in a downed tree and the wood in a home, they can be a very serious pest and are responsible for the majority of insect related wood damage to homes. These termites may consume any wood that is in contact with the soil.  Stakes, buried wood scraps from newly constructed homes and possibly even mulch, may be consumed if found by foraging termites.  However, the nests in which the queen resides, have never been documented to occur in even thick piles of mulch. Therefore, in answer to the question, “will termites spread via mulch retail in Indiana”, the answer is NO.

The benefits of proper use of mulches such as water conservation, reduced used of herbicides, and reduced soil erosion continue to outweigh any risk of termite attraction and infestation.

Our current termite recommendation is to be vigilant and up-to-date with termite inspections (and treatments if needed) in or on the house: Termite Control. Do not worry about mulch bringing in termites.

Links to other information:

Mulch and Soil Council news release March 6, 2006

Louisiana Dept. of Ag and Forestry--Mulch Rumors Untrue

LSUAg Center --Formosan Subterranean Termite Biology and Quarantine Information

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The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by the Purdue University Cooperative Extension Service is implied. Any person using products listed assumes full responsibility for their use in accordance with current direction of the manufacturer. Purdue University is an equal opportunity/equal access institution.

Information listed is valid only for the state of Indiana