Agriculture Reference
In-Depth Information
under conventional treatment (Williams
et
al
., 2005). In public housing heavily infested
with
B. germanica
, an IPM programme that
included vacuuming, monitoring and bait-
ing successfully reduced the cockroach
population better than monthly baseboard
and crack-and-crevice treatment with
insecticide sprays and dusts (Miller and
Meek, 2004). In this fi eld evaluation, the
IPM strategy reduced the cockroach popu-
lation by 75% after 3 months and con-
sistently maintained about 80% reduction
for up to a year. In comparison, the base-
board and crack-and-crevice treatments did
not reduce cockroach infestation and a
sharp increase (about 220%) in cockroach
trap catch occurred during the peak popu-
lation seasons. The IPM approach also used
less insecticide (1.1-5.7 g per apartment
unit per month) than the baseboard and
crack-and-crevice treatments (96.0-294.1 g)
(Miller and Meek, 2004). Control of
B.
germanica
using the fundamental elements
of IPM (inspection-guided baiting) signifi -
cantly reduced cockroach populations
compared with conventional residual spray
treatment in multiple-unit public housing
(Sever
et al
., 2007) and food preparation
establishments (Lee, 2002). Effective control
of
B. germanica
also contributed to lower
concentrations of indoor cockroach aller-
gens in IPM-treated apartments compared
with untreated and conventional treated
houses (Sever
et al
., 2007).
The cost of IPM programmes is higher
than that of conventional treatment during
the initial stage of implementation. Once
the IPM programme is established, however,
its cost is similar to that of conventional
treatments. For example, during the initial
stage of cockroach control in public
housing, Miller and Meek (2004) reported
that IPM with vacuuming, monitoring traps
and baiting cost more (US$5.16-14.60 per
apartment unit monthly) compared with
conventional treatment (< $2.75). This
higher cost was due in part to the additional
labour required for vacuuming and
placement of traps and the higher product
cost. After a while, however, the cost of the
maintenance phase with IPM was reduced
to $0.87-2.97, which was similar to the cost
for conventional treatment ($1.18-1.52).
The reduction in IPM cost was due to lower
quantities of insecticide and the fewer
treatment trips needed after cockroach
populations were suppressed.
For IPM programmes that consist only of
monitoring-guided baiting, the cost is
comparable to that of conventional residual
treatment. Lee (2002) reported that the cost
of cockroach IPM in Malaysia was $0.08-
0.30 per m
2
, which was similar to that of
residual treatment ($0.17-0.30 per m
2
). In
another study conducted in schools, the
cost per service for IPM was $8.57, which
was comparable to the cost of residual
treatment ($7.49). Also, the timing of IPM-
related tasks was fl exible (Lee, 2002;
Williams
et al
., 2005). In contrast, residual
treatment tasks could only be conducted
after operation hours when businesses were
closed (Lee, 2002) or at specifi c times when
rooms in schools were vacant (Williams
et
al
., 2005). Re-treatment cost because of
insecticide resistance could also result in
additional costs (Lee, 2002), whereas baiting
would overcome insecticide-resistant popu-
lations (Lee, 1998).
Cockroach Feeding Behaviour
For bait to be competitive when placed in
the cockroach environment, it must contain
nutrients that are limited and novel in the
cockroach environment (Reierson, 1995;
Durier and Rivault, 2001) because food
nutrition affects development and repro-
duction in cockroaches (Hamilton
et al
.,
1990; Cooper and Schal, 1992). Cockroaches
are known to self-select nutrients to fi ll
nutrient defi ciencies when they are sub-
jected to an imbalanced food source. For
example,
Supella longipalpa
nymphs
self-
selected a 15.5:84.5 protein:carbohydrate
diet when they were reared with two
imbalanced diet cubes, one lacking protein
and the other lacking carbohydrate. When
they were given diets composed of 20:80
protein:carbohydrate, however, most of the
nymphs did not grow into the adult stage
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