Rh. Scheffrahn et al., Chemical prevention of colony foundation by Cryptotermes brevis (Isoptera : Kalotermitidae) in attic modules, J ECON ENT, 94(4), 2001, pp. 915-919
Disodium octaborate tetrahydrate (DOT) dust, DOT aqueous solution, imidaclo
prid dust, and amorphous silica gel dust with synergized 1% pyrethrins were
applied on wood surfaces to simulated attic modules. Modules (30 by 30 cm)
with and without fiberglass insulation were exposed to dispersal flights o
f Cryptotermes brevis (Walker) in May and June of 1998 and 1999. Six months
after flights, modules were disassembled and inspected for nuptial chamber
location and contents, During both years, air and water control treatments
contained 22.2 +/- 9.94 (mean +/- SD) nuptial chambers, 7.5 +/- 5.7 live i
magos, and 2.0 +/- 1.4 chambers with brood. This survivorship indicated tha
t the attic modules performed well as a colonizing platform for C, brevis.
C, brevis dealates preferred constructing nuptial chambers in the crevices
at the bases or tops of the modules instead of internal crevices. Modules t
reated in 1998 and 1999 with DOT or silica dusts contained no live termites
, whereas zero of five modules treated with imidacloprid dust in 1998 and t
wo of 20 modules treated with imidacloprid dust in 1999 contained single li
ve incipient colonies. In 1998, 15% DOT solution, applied as a postconstruc
tion treatment, yielded significantly fewer chambers and live termites than
controls, but was not as effective as dusts in preventing successful colon
ization. In 1999, the DOT solution, applied as a construction-phase treatme
nt, was equally as effective in preventing colonization as the dust treatme
nts during that year. Results indicate that dust formulations of DOT, silic
a gel, and imidacloprid can be used to prevent drywood termite colonization
in existing building voids and attics. Where the entire wood framing is ex
posed to treatment, such as during building construction, aqueous DOT solut
ion can be equally effective as dusts in preventing colonization by C. brev
is.