Management of Drywood Termites: Past Practices, Present Situation and Future Prospects - Urban Insect Pests: Sustainable Management Strategies - page 135

(Hennessy, 1993) and were soon required to
be certifi ed by state law (Light et al. , 1930).
At that time, management recommendations
involved the use of copper aceto arsenite
and calcium arsenate dusts (Randall and
Doody, 1934a), hydrogen cyanide (Randall
et al. , 1934b) and wood removal (Hennessy,
1993). In the past 20 years, there have been
a number of reviews on drywood termite
management (Lewis, 1997, 2003; Su and
Scheffrahn, 2000; Potter, 2011).
Interventions aimed at controlling
drywood termite infestations are typically
placed into two broad categories - remedial
or preventative - with further divisions into
local (sometimes called spot treatments) or
whole-structure approaches (Table 9.2).
Remedial interventions are intended to kill
termites present at the time of application,
whereas preventive interventions are
intended to stop or prevent infestation, i.e.
initial colony formation. Local remedial
treatments are the oldest known pesticide
intervention for drywood termites and are
generally restricted to a single or small
group of boards or locations within boards,
whereas whole-structure interventions are
defi ned as the simultaneous treatment of all
wood in a structure (Scheffrahn and Su,
1994). Estimates on the proportion of
intervention categories that are used for
controlling drywood termite infestations

are diffi cult to ascertain; however, in
California at least 90% of all drywood
termite treatments involve application of
pesticides (Lewis, 2003).

Remedial Interventions

Wood replacement

Wood removal and replacement, although
not discussed in the literature, must have
been a commonly used drywood termite
management tool in historic times.
Removing and replacing infested wood as a
remedial intervention is typically not
offered as a service option to consumers by
today's pest management industry. This
service, when available, is highly variable
among and within states and heavily
dependent on the carpentry talent available
in companies and building code/permit
requirements, and can be logistically chal-
lenging and cost prohibitive with extensive
infestations. The fact that a drywood
infestation can be eliminated by removing
and replacing wood is undeniable and has
been used by the authors on numerous
occasions with several species of drywood
termites including Cryptotermes brevis
(Walker), Incisitermes milleri (Emerson), I.
minor and Incisitermes snyderi (Light).

Table 9.2. List of management options for control of drywood termite infestations and categorizing each
as local or whole-structure treatments, preventative or remedial treatments and if that treatment has
residual activity against drywood termites.

Local/spot (L) or
whole-structure (WS)

Preventative (P) or
remedial (Re)

Residual activity (Y= yes) (N=
no) a Type of treatment

Wood replacement L Re Y - if pressure-treated wood

is used
N - if treated wood not used

Wood surface L or WS P Y - depends on AI b

Y - depends on AI b Wood injection L Re

Fumigation/asphyxiation L or WS Re N

Temperature L or WS Re N

Microwave L Re N

Electricity L Re N

Pathogens L Re Unknown

Pressure-treated wood L or WS P Y

a Residual activity is defi ned as a treatment that has a detrimental impact on drywood termites after the treatment is
conducted. b AI stands for active ingredient in a pesticidal formulation.