Agriculture Reference
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treatments for drywood termites using the
ELECTRO-GUN® have been reported with
highly variable results with effi cacy depend-
ent on application technique (surface versus
drilling and inserting a metal pin), treatment
time per test board (7 min versus 22 min)
and species of drywood termite (
I. minor
and
Cryptotermes primus
(Hill)) (Ebeling,
1983; Lewis and Haverty 1996, 2001;
Creffi eld
et al.
, 1997). Damage from drill-
and-pin applications was reported to some
of the test boards (Lewis and Haverty, 2001).
nuclear polyhedrosis virus against
Kalo-
termes fl avicollis
Fab. (Grace, 1997); the
bacteria
Bacillus thuringiensis
Berliner and
Bacillus sphaericus
(Meyer and Neide)
involving
K. fl avicollis
and
C. brevis
(Moein
et al
., 1996; Grace, 1997; Moein and Nasr,
1998); the nematode
Heterorhabditis
spp.
directed at
Glyptotermes dilatatus
(Bugnion
and Popoff) (Su and Scheffrahn, 2000) and
entomopathogenic fungi against
C. brevis
and
I. snyderi
(Nasr and Moein, 1997;
Calleri
et al
., 2010). The fungus
Metarhizium
anisopliae
(Strain ESC 1) is registered for
Incisitermes
spp
.
in the USA (Su and
Scheffrahn, 2000). A recent review article
suggests, however, that more research is
needed before the practical application of
biological control of termites can be realized
(Chouvenc
et al
., 2011).
Microwave
Microwaves of 2.4 GHz frequency oscillate
water and fat cells creating heat that
denatures proteins and disrupts cell
membranes, resulting in cell death (Hall,
1981). The application of this intervention
includes mounting a large open-door
microwave-generating device (some more
than 10,000 watts in power) several inches
from an infested piece of wood. The lethal
effects of microwaves to drywood termites
has been reported from laboratory and
simulated fi eld studies and results were
mixed depending on the device, wattage of
the device, operator ability to delimit the
exact location of the infested wood in walls
and presence of wall covering (Lewis and
Haverty, 1996; Lewis
et al.
, 2000). Add-
itional concerns that can arise from micro-
wave treatments include: long treatment
time and inability to reach infestations in
upper portions of a wall, ceilings and
cramped areas of crawlspaces and attics.
Overheating of wood and walls resulting in
burned and damaged wood/wall coverings
has also been reported (Lewis and Haverty,
1996).
Preventative Interventions
Historical records that mention wood
preservative use go back several thousand
years when they were fi rst used to prevent
mould growth on sheets of papyrus in Egypt
and wooden chopsticks in China (Freeman,
2003). The earliest US patent for a wood
preservative was issued to Dr William Crook
in South Carolina in 1716 (Freeman
et al.
,
2003). However, it was not until patents for
coal-tar creosote and a pressure impreg-
nation process in the early 1800s that the
commercialization and wide-scale use of
pressure-treated wood occurred (Freeman
et al
., 2003). The earliest fi eld use of
pressure-treated wood was for railroad
sleepers and telephone poles for the
prevention of damage by subterranean ter-
mites and wood decay (Randall and Doody,
1934b; Freeman
et al.
, 2003; Freeman and
McIntyre 2008). Creation of the uniform
building code and the post-World War II
building boom extended the need for, and
use of, pressure-treated wood (SSBC, 1946;
McKeevar and Howard, 2011).
Some of the earliest chemicals used for
wood preservation were compounds con-
taining metallic salts of mercuric chloride,
copper sulfate and zinc chloride (Freeman
et al.
, 2003). The process of applying these
Pathogens
The use of insect pathogens and parasites
directed at drywood termite control has
been limited and most attempts have been
reported as failures (Grace, 1997; Su and
Scheffrahn, 2000; Chouvenc
et al
., 2011).
Published studies include the use of the
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