Termite Products and Colony
Elimination (https://professionalpestmanager.com/termite-professional-seminars-2026/seminar-summary/)

The first stage of any best practice
termite treatment involves the elimination of active termites from the
building. Location and elimination of the nest is also ideal, but it is the
elimination of active termites from the building that is essential. A range of
product formats are registered for eliminating termites from the building,
namely dusts, foams and baits. All three product formats are capable of
eliminating active termites from a building, but only baits have proven colony
elimination abilities. 

 When considering the performance of
products, proof of claim is generally provided on the label (supporting data
has been provided to regulatory authorities) or through research that has been
published in peer-reviewed journals. Peer-reviewed data on foams and dusts is
quite limited. A couple of papers demonstrate the horizontal transfer in dusts
and liquids in laboratory trials, but there is no specific data on foams.

 Baits can deliver very reliable
colony elimination of heterotermitids (Coptotermes and Heterotermes), but the
speed of action is influenced by temperature. Elimination can take less than
three months in the warmer months but can take 3-6 months if the treatment
includes the winter period. Baits are also an option for Schedorhinotermes,
although it is necessary to take into account its multi-nest colony structure.
For example, termites from non-treated nests can appear in the termite workings
after elimination of the treated nest, which can cause confusion as to whether
the product has eliminated the nest. For termitids such as Nasutitermes and
Microcerotermes, baits can still work, but take considerably longer. 

Soil Treatment Trials using whole
colonies of Coptotermes formosanus, with treated soil placed at varying
distances between the nest and the feeding site, demonstrated four key
phenomena:

Termite mortality was generally
confined to within 3-5 m of the treatment;

Termites sealed off the foraging
tunnel connected to the treated soil and continued foraging in non-treated
soil;

Although numbers were initially
reduced, the termite colonies survived, even when the treated soil was only 1.5
m from the nest;

Termites remained active at the
feeding site after treatment.

The act of sealing off the foraging
tunnel leading to the treated soil is termed secondary repellency – the
termites seal off and avoid an area of significant termite death.

Two conclusions can be drawn from
these studies. Firstly, that installing a soil treatment before confirming the
elimination of termites from the structure runs the risk of trapping termites
within the structure – this applies to both repellent and ‘non-repellent’
termiticides. Secondly, soil treatments on their own are unlikely to deliver
colony elimination. These observations emphasise the need to follow best
practice: eliminate active termites before applying a soil treatment.