Termite Interceptors

Termite Interception

Basic & Advanced Concepts


Summary: Termite interceptors entice termites to feed on the food inside them.  In the process, they intercept the entire termite colony.  Here's why that happens: Each termite spends only a short period of time in the interceptor, then moves on toward another feeding spot, while another hungry termite takes its place. Every termite worker travels a path that takes it to all or most of the colony's feeding spots within the colony's foraging zone.  An imporant result of termite interception is that it opens a window into the termite colony.  Termiticides inoculated thru that window disrupt the termite colony's natural organization, and reduces their ability to infest and damage manufactured structures and botanicals such as living trees and shrubs.  According to one eminent entomologist (Dr. Vernard Lewis, University of California, Berkeley), safer, non-chemical termiticides should be used as inoculums, even if elimination takes longer.  Another (Dr. J. Kenneth Grace, University of Hawaii) suggests that, in theory, the right kind of biological termiticide will provide that alternative, and will work as efficiently as the best chemical termiticide.  Our studies show that entomopathogenic nematodes (EPN), either alone or in combination with other biological agents, meet the requirements stipulated by both authorities, when used in termite interceptors optimized for biological agents. Scroll down to read full text of of article.  Next...   Home...


The EntomoBiotic Termite Interceptor, Annunciator, & Inoculator (TIAI)  was made to be placed in the ground around structures to intercept subterranean termite colonies and alert users to their presence. It was based on a concept that was first described by two PhD entomologists, Glenn Esenther and Ray Beal, in the 1960's.

When a termite colony is intercepted, the termite interceptor feeds termite food continuously to the termite colony, by feeding individual members of the colony as they pass through it.  Though this concept, advanced by Esenther and Beal, is quite simple, it is easy to misunderstand.  For example, many think that termite interceptors act primarily as termite traps, but that is not the case.  The following terminology applies:

            •  Termite interceptors intercept termite colonies, by feeding individual termite workers

            •  As termite interceptors become incorporated into the food circuit used by individual termite workers, they manage to intercept the entire termite colony the workers belong to.

            •  Termite interceptors aren't termite traps, because the intercepted termites are free to come and go as they please. Hungry termites enter individually, eat their fill, then trek on to another feeding spot (which may or may not be another termite interceptor). The interceptor serves more as a termite concentration node, where humans may interface with the termite colony and take steps to nullify the termite colony's ability to damage cellulose-based matter of economic value. One way is to inoculate individual termite workers with termiticidal agents; if the right inoculum is used, the workers then carry it out of the interceptor, and distribute it to the entire termite colony.

In general, each termite that enters the termite interceptor stays just long enough to eat, and then moves on.  By installing several termite interceptors in the soil around a building, a user who succeeds in continually attracting termite workers to the interceptors, manages to intercept the entire termite colony.  This effect obtains because most, if not all, of the worker workers in the termite colony will pass through the installed interceptors at least once within a given period of time, regardless of the number of other (non-interceptor) feeding spots the termite colony may be utilizing. 

Two Basic Criteria

Termites feeding in a termite interceptor are attracted by the quality of the termite food it contains. To perform well, the termite interceptor must satisfy at least two criteria:

            •  Its food material should be at least as attractive as the other feeding spots in the colony's food circuit, and

            •  It should contain enough food to feed millions of termites.

These criteria affect the design of the termite interceptor in important ways.  For example, food attractiveness can be affected by organic contaminants introduced after the interceptor is installed.  The most problematic contaminants are microorganisms normally associated with composting processes, such as bacteria and fungi, that compete with termites for available stores of cellulose in the soil.  If the interior of the interceptor is too moist too often, and is not ventilated enough to permit efficient gas exchange with ambient air, composting microorganisms will take over and rot its cellulose store, making it unpalatable to termites.

Under ideal conditions the interceptor's architecture and composition will lessen or even eliminate the risk that such contaminants will thrive inside it.  Unless this feature is properly designed in, the interceptor may become so contaminated as to fail to attract termites that find it. Since the termites pass it by, it does not get an opportunity to signal their presence. This gives the mistaken impression, to an observer who inspects the interceptors periodically, that no termites are foraging in the area.  Such failures to alarm are worse than false alarms, as the unwarranted sense of security they provide may allow termites to thrive in that location, undetected, for long enough periods to potentially cause economic damage.

The Object: Termite Colony Nullification

Termite interception should lead to termite control, and termite control, at the very least, should act to nullify the ability of entire termite colonies to infest and damage manufactured structures and botanicals such as living trees and shrubs.  This is different from termite colony elimination. It is well known that termite colony "elimination" cannot be proved under real-world conditions. On the other hand, termite colony "nullification" can be demonstrated, over a period of time, by showing that termite infestations and the damage they cause has ceased.

Termite colony nullification can be carried out in a number of ways. However, human safety comes first.  Vernard R. Lewis, a termite biologist at the University of California, Berkeley, who has devoted much of his career to researching non-chemical termite-control methods, noted in a 1996 paper he published on alternative control strategies for termites, that traditional methods of control are unacceptable.  Such methods focus more on control, Dr. Lewis wrote, than on safety.  Low-toxicity or non-toxic methods, that are safer to the humans who use or are otherwise exposed to them, must be given priority, he added, even if a certain amount of control has to be sacrificed. 

J. Kenneth Grace, a termite biologist at the University of Hawaii, later asserted in a paper on approaches to biological control of termites, that total destruction of termite colonies was possible with safer methods.  Biological control agents might even perform as effectively as chemical agents,  Dr. Grace suggested, provided certain criteria were met:

          "Microbial control is a balancing act, in that pathogens must not be repellent, and must not have such rapid or dramatic effects upon the infected individuals that others will subsequently avoid contact with them or with the inoculum source. On the other hand, they must be capable of distribution through the colony and induction of either an epizootic or sufficient delayed mortality to essentially destroy the colony. A self-replicating time bomb, akin to a computer virus, would be the ideal microbial control agent."  J. Kenneth Grace, Sociobiology Vol. 41A, 2003, in an article entitled Approaches to Biological Control of Termites.



Links to Important patents and articles related to termite detectors and interceptors:

Barbara Thorne, University of Maryland, website: http://www.lfsc-courses.umd.edu/cv/?department=entm_cv&name=bthorne  Dr. Thorne, in collaboration with James Traniello, designed the first cartridge-type termite detector and bait station.  Her website links to a number of scientific articles on termite biology. 

Timothy Myles, University of Toronto, patent entitled "Method, Apparatus and Composition for Treating Insects." U.S. Patent No. 5,609,879: http://www.utoronto.ca/forest/termite/ScheduleOCR Output/USPat1.pdf Note that this patent, which describes a method and apparatus for dealing with subterranean termites, broke new ground on several fronts and departed significantly from the methodology taught by Dr. Thorne in her patented termite detection cartridge and bait station.

Please send suggested additions to the above list, or corrections to any of the captions provided, to jerry.cates@entomobiotics.com.