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Baiting for success

Annual COCKROACH Control Issue
Baiting for SucceSS
Which urban pest is the most difficult to control? Most
PMPs say ants.
But the answer to this question has shifted completely
over the past 20 years from cockroaches to ants. Today,
few people consider the German cockroach a difficult pest to
manage. What made the change is the invention of highly effec-
tive baits, in particular, gel baits. Then, the question is, why is
the German cockroach still common in urban areas? The Ger-
man cockroach’s small size, short life cycle, high reproductive
potential and resistance development are well-known factors
accounting for their success. However, a frequently ignored fac-
tor is poor pest control practices. Despite the plethora of effec-
tive tools and methods available, it is not uncommon to find
people, including professionals, relying on ineffective materials
or methods to treat cockroach infestations.
Studies have shown that an Integrated Pest Management
(IPM) approach incorporating bait and other non-chemical
By Changlu Wang, Narinderpal Singh, Richard Cooper and Clay Scherer
Research from Rutgers finds
a one-time application of
gel bait can achieve nearly
100 percent reduction in
cockroach numbers within
a month even without
changing the apartment
sanitation conditions.
methods can provide a high level of cockroach control (Miller
and Meek 2000, Wang and Bennett 2009). Baiting alone result-
ed in a more than 95 percent reduction of cockroaches in heav-
ily infested apartments (Wang and Bennett 2006, Wang 2011).
The high efficacy of gel bait is due to the palatable bait matrices,
non-repellent active ingredients, and, to some degree, the trans-
fer of bait active ingredients among individuals (Buczkowski et
al. 2008).
Sadly, these simple and effective strategies are ignored by or
are unknown to communities that still suffer chronic cockroach
infestations. Some professionals are not properly trained to use
these control strategies correctly. To demonstrate how cock-
roach bait can be effectively used to control cockroach infesta-
tions, we conducted a study in an apartment building. In the
study, we showed that one-time application of a gel bait product
provided 99 percent reduction in German cockroach counts af-
ter a four-week period.
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Annual COCKROACH Control Issue reader service #46
STUDY METHODS. We selected eight
apartments from a high-rise apartment
building in Newark, N.J. The sizes of
the apartments were 450 square feet (a
studio apartment) or 600 square feet (a
one-bedroom apartment). A contractor
hired by the property management of-
fice serviced the building monthly and
used insecticide sprays for cockroach
complaints. All apartments were occu-
pied by low-income senior citizens. Old
cockroach bait residues existed in four
apartments. Six apartments used aerosol
sprays for cockroaches.
Prior to the treatment, we placed six
Trapper Monitor & Insect Traps (Bell
Laboratories) in each apartment. Loca-
tions of the traps were: 1) inside the cabi-
netry under the kitchen sink, 2) in the
cabinetry above the kitchen sink, 3) be-
side the stove, 4) beside the refrigerator,
5) the living room corner near the dining
table or where food was served and 6) on
the floor behind the toilet. The pre-count
trapping interval varied between one and
eight days due to difficulties in gaining
access to two apartments, coupled with
low trap count in one apartment. The av-
erage daily trap catch of these apartments
ranged from 6 to 150 cockroaches with a
median count of 16.
One to two researchers from Rutgers
University applied Advion Cockroach Gel
Bait (Syngenta Professional Products) in
each apartment using a baiting gun or
plunger into cockroach harborages fol-
lowing the same pattern as that by Wang
(2010). The size of each bait placement
was about 0.1 g. The amount of bait used
in each apartment ranged from 18 to 87 g
with a median of 44 g. Median technician
time (time in each apartment × number
of technicians) spent treating each apart-
ment was 23 minutes. To evaluate effi-
cacy, we placed sticky traps at one, two,
three and four weeks post treatment and
Week after treatment
Mean trap count reduction (%)
97% 99%
2 3 4
Figure 1. Ecacy of Advion gel bait treatment on German cockroach populations in apartments.
62 /// july 2013
Annual COCKROACH Control Issue reader service #48 reader service #65
collected the traps after one-to-eight days
as we did in the pre-treatment monitor-
ing. The total number of cockroaches
found in traps in each apartment was
compared with the pre-treatment count
to calculate percent reduction.
STUDY RESULTS. One application of
Advion Cockroach Gel Bait resulted in
72, 88, 97 and 99 percent mean cock-
roach count reduction at one, two, three
and four weeks post-treatment, respec-
tively (see Figure 1 on page 62). Among the
eight apartments, only two apartments
still had cockroaches after four weeks.
There were no noticeable changes in the
residents’ housekeeping practices. A few
apartments had clutter, spilled drinks
and accumulation of garbage in kitchens
and bedrooms throughout the study pe-
riod. These conditions created numerous
cockroach harborages and affected the
control efficacy. All residents were very
satisfied with the results.
CONCLUSIONS. Application of gel baits
is still the most effective chemical meth-
od for managing German cockroach in-
festations. A one-time application of gel
bait can achieve nearly 100 percent re-
duction in cockroach numbers within a
month without changing the apartment
sanitation conditions. The efficacy is de-
pendent on the applicator’s knowledge,
experience and using sticky traps for
monitoring cockroach distributions. An
IPM approach incorporating client edu-
cation, sanitation, decluttering, monitor-
ing traps and baiting is the key to long-
term control of German cockroaches.
Authors’ acknowledgement: This study was
sponsored by DuPont Professional Products,
now Syngenta Professional Products.
Changlu Wang, Narinderpal Singh and Richard
Cooper are with the Department of Entomol-
ogy, Rutgers University, New Brunswick, N.J. Clay
Scherer is with Syngenta Crop Protection.
Buczkowski, G., Scherer, C., and G. W. Ben-
nett. 2008. Horizontal transfer of bait in the
German cockroach: indoxacarb causes sec-
ondary and tertiary mortality. Journal of Eco-
nomic Entomology 101: 894-901.
Miller, D., and F. Meek. 2004. Cost and
efficacy comparison of integrated pest man-
agement strategies with monthly spray in-
secticide applications for German cockroach
(Dictyoptera: Blattellidae) control in public
housing. Journal of Economic Entomology. 97:
Wang, C., and G. W. Bennett. 2006. Com-
parative study of integrated pest management
and baiting for German cockroach manage-
ment in public housing. Journal of Economic
Entomology 99: 879-885.
Wang, C., and G. W. Bennett. 2009. Cost
and effectiveness of community-wide inte-
grated pest management for German cock-
roach, cockroach allergen, and insecticide use
reduction in low-income housing. Journal of
Economic Entomology 102: 1614-1623.
Wang, C. 2010. When less is more. Pest
Control Technology 38(7): 72, 74, 76, 78.
64 /// july 2013
... This may have to do with the high cockroach infestation rates and frequent re-infestations in apartment buildings. Cockroach baits have existed in the U.S. market for over 25 yr and are proven to be very effective for eliminating cockroach infestations (Appel 1992, Nalyanya et al. 2001, Appel 2003, Wang and Bennett 2006, Wang et al. 2013. However, 55% of the surveyed residents purchased insecticide sprays for control rather than baits in an effort to control cockroaches themselves. ...
Full-text available
The German cockroach, Blattella germanica (L.), is a common pest found in apartment buildings. Prevalence of cockroach infestations is affected by both environmental conditions and building occupant behavior, but their relationships are not well studied. The objective of this study was to analyze the presence of German cockroaches in relation to environmental conditions, resident demographics, and residents' tolerance of cockroaches. We conducted resident interviews, placed sticky traps to detect the presence of German cockroaches, and assessed apartment conditions. A total of 388 apartments from seven low-income apartment buildings, occupied by senior citizens in New Jersey, United States, were included. Among the 344 apartments where trap count data were obtained, 30% had German cockroaches. Among interviewed residents whose apartments had existing cockroach infestations, 36% were unaware of the presence of cockroaches. The odds of having cockroaches in apartments with a 'poor' sanitation rating in kitchens and bathrooms was 2.7 times greater than that in apartments with better sanitation conditions. Residents' tolerance to cockroaches is significantly associated with presence of cockroaches and cockroach population size. The median cockroach count when residents were bothered by cockroaches was ≥3, based on deployment of 4 sticky traps per apartment, over a 2-wk period. Assessing and reducing cockroach tolerance thresholds and improving housekeeping through resident education and assistance from community and housing management should be incorporated in future cockroach management programs in order to reduce high cockroach infestation rates found in similar communities.
Full-text available
Pest infestations in residential buildings are common, but community-wide pest survey data are lacking. Frequent insecticide applications for controlling indoor pests leave insecticide residues and pose potential health risks to residents. In this study, a community-wide pest survey was carried out in a housing complex consisting of 258 units in 40 buildings in New Brunswick, New Jersey. It was immediately followed by implementation of an integrated pest management (IPM) program in all the cockroach-infested apartments and two bed bug apartments with the goal of eliminating pest infestations, reducing pyrethroid residues, and increasing resident satisfaction with pest control services. The IPM-treated apartments were revisited and treated biweekly or monthly for 7 mo. Initial inspection found the top three pests and their infestation rates to be as follows: German cockroaches (Blattella germanica L. [Blattodea: Blattellidae]), 28%; rodents, 11%; and bed bugs (Cimex lectularius L. [Hemiptera: Cimicidae]), 8%. Floor wipe samples were collected in the kitchens and bedrooms of 20 apartments for pyrethroid residue analysis before the IPM implementation; 17 of the 20 apartments were resampled again at 7 mo. The IPM program reduced cockroach counts per apartment by 88% at 7 wk after initial treatment. At 7 mo, 85% of the cockroach infestations found in the initial survey were eliminated. The average number of pyrethroids detected decreased significantly from 6 ± 1 (mean ± SEM) and 5 ± 1 to 2 ± 1 and 3 ± 1 in the kitchens and bedrooms, respectively. The average concentrations of targeted pyrethroids residue also decreased significantly in the kitchens and bedrooms.
Full-text available
Horizontal transfer of indoxacarb in the German cockroach, Blattella germanica (L.), was examined under laboratory conditions. Results show that a single bait-fed adult cockroach (i.e., the donor) transferred indoxacarb to numerous primary recipients (secondary mortality),which then became secondary donors. These recipients subsequently became donors to other cockroaches and caused significant mortality in other members of the aggregation, resulting in tertiary kill. Indoxacarb was effectively transferred among adult cockroaches and resulted in significant secondary mortality. When adult males served as donors and vectored the insecticide to adult males, the donor:recipient ratio affected the mortality of the recipients and the rate of secondary mortality increased with increasing the ratio of donors to recipients. Furthermore, secondary mortality in the untreated cockroaches was significantly affected by the freshness of excretions from the donors, the presence of alternative food, and the duration of contact between the donors and the recipients. Ingested indoxacarb was most effectively translocated when the recipients interacted with freshly symptomatic donors in the absence of alternative food. The transfer of indoxacarb continued beyond secondary mortality and resulted in significant tertiary mortality. Excretions from a single bait-fed adult killed 38/50 (76%) nymphs within 72 h. The dead nymphs then vectored indoxacarb to 20 adult males and killed 16/20 (81%) recipients within 72 h. Behavioral mechanisms involved in the horizontal transfer of indoxacarb may include: contact with excretions, necrophagy, emetophagy, and ingestion of other excretions that originate from the donors.
Many low-income housing units in the United States continue to have chronic German cockroach, Blattella germanica (L.), infestations and high prevalence of cockroach allergens despite the availability of highly effective cockroach control products. Several studies have demonstrated the greater effectiveness of integrated pest management (IPM) compared with routine chemical interventions in apartment buildings and the benefit of cockroach allergen reduction using IPM. Yet, there has been little information on the cost and benefit of community-wide cockroach IPM, which is critical for voluntary adoption of IPM programs. We evaluated a community-wide IPM program in two low-income apartment complexes in Gary, IN. The program included education of staff and residents, monthly monitoring, and nonchemical (laying sticky traps) and chemical treatment based on monitoring results. One complex of 191 apartments was treated with cockroach gel bait, boric acid dust, and sticky traps by state licensed entomologists from Purdue University (E-IPM group). The other complex of 251 apartments was treated by pest management professionals (PMPs) from a contractor (C-IPM group) following the same protocol as the E-IPM group. Purdue University researchers trained Gary Housing Authority (GHA) staff on cockroach biology and management and cockroach allergen reduction techniques. GHA staff educated all residents in the two complexes on cockroach control and allergen reduction through printed materials, demonstrations, or both. Purdue University entomologists conducted the initial and monthly monitoring in both complexes (laying six sticky traps per apartment and retrieving them the next day) with the assistance from GHA to evaluate program effectiveness, guide insecticide applications, and identify apartments with poor sanitation conditions. Dust samples were collected from kitchen floors of 72 cockroach-infested apartments at the beginning, and again at 6 and 12 mo to evaluate changes in cockroach allergen Bla g 1 concentration. E-IPM resulted in significantly faster cockroach trap count reduction than C-IPM. At 12 mo, the number of cockroach-infested apartments decreased by 74% in both treatment groups. Geometric mean cockroach trap counts decreased from 99.7 at baseline to 0.4 (99.6% reduction) by E-IPM and from 76.0 at baseline to 1.3 (98.3% reduction) by C-IPM. From the first quarter to the fourth quarter, cockroach bait use decreased by 88.5 and 92.7% for E-IPM and C-IPM group, respectively. From month 0 to month 12, geometric mean Bla g 1 concentrations decreased from 27.8 to 2.2 U per gram of dust (U/g) in the E-IPM group and from 5.8 to 2.4 U/g in the C-IPM group. Assuming salary rates at $60/h for PMPs and $19/h for housing authority staff, the mean monthly cockroach management (material and labor expenses) cost was $7.5 USD/apartment for both groups excluding education cost. The cost for subsequent years service is expected to be lower due to reduced cockroach infestations. The effectiveness of both IPM programs was affected by the lack of assistance from housing authority with periodic inspections of the apartments, lack of proper maintenance of the properties, and inadequate cooperation from residents.
The long-term costs and efficacy of two treatment methodologies for German cockroach, Blattella germanica (L.), control were compared in the public housing environment. The "traditional" treatment for German cockroaches consisted of monthly baseboard and crack and crevice treatment (TBCC) by using spray and dust formulation insecticides. The integrated pest management treatment (IPM) involved initial vacuuming of apartments followed by monthly or quarterly applications of baits and insect growth regulator (IGR) devices. Cockroach populations in the IPM treatment were also monitored with sticky traps. Technician time and the amount of product applied were used to measure cost in both treatments. Twenty-four hour sticky trap catch was used as an indicator of treatment efficacy. The cost of the IPM treatment was found to be significantly greater than the traditional treatment, particularly at the initiation of the test. In the first month (clean-out), the average cost per apartment unit was dollar 14.60, whereas the average cost of a TBCC unit was dollar 2.75. In the second month of treatment, the average cost of IPM was still significantly greater than the TBCC cost. However, after month 4 the cost of the two treatments was no longer significantly different because many of the IPM apartments were moved to a quarterly treatment schedule. To evaluate the long-term costs of the two treatments over the entire year, technician time and product quantities were averaged over all units treated within the 12-mo test period (total 600 U per treatment). The average per unit cost of the IPM treatment was (dollar 4.06). The average IPM cost was significantly greater than that of the TBCC treatment at dollar 1.50 per unit. Although the TBCC was significantly less expensive than the IPM treatment, it was also less effective. Trap catch data indicated that the TBCC treatment had little, if any, effect on the cockroach populations over the course of the year. Cockroach populations in the TBCC treatment remained steady for the first 5 mo of the test and then had a threefold increase during the summer. Cockroach populations in the IPM treatment were significantly reduced from an average of 24.7 cockroaches per unit before treatment to an average 3.9 cockroaches per unit in month 4. The suppressed cockroach populations (< 5 per unit) in the IPM treatment remained constant for the remaining 8 mo of the test.
This study assessed the cost and effectiveness of a building-wide cockroach integrated pest management (IPM) program compared with bait alone treatment in public housing. In total, 12 buildings (66 apartments) were treated and monitored for cockroach infestations over 7 mo. The buildings were divided into two groups: bait treatment and IPM. Apartments in the bait alone group were treated with Maxforce FC Select (0.01% fipronil) during the first 12 wk and Maxforce Roach Killer Bait Gel (2.15% hydramethylnon) from 16 wk when necessary. For the IPM group, cockroaches were flushed and vacuumed at the beginning of the study; sticky traps were placed in all apartments to monitor and reduce cockroach numbers; educational materials were delivered to the residents; and Maxforce FC Select and Maxforce Roach Killer Bait Gel were applied to kill cockroaches. Two seminars were presented to the manger, and Community Service Program staff of the Gary Housing Authority to help gain tenant cooperation in the program. Effects of the treatments were monitored using sticky traps (six per apartment) at 2, 4, 8, 12, 16, and 29 wk after treatment. More treatments were applied during each monitoring visit when necessary. Those apartments with high levels of infestations (> or =12 cockroaches in six traps) before treatment were used to compare the IPM and bait only treatments. IPM resulted in significantly greater trap catch reduction than the bait treatment. The IPM (n=12) and bait only treatment (n=11) resulted in 100.0 and 94.6%, respectively, reduction in trap catch after 16 wk. At 29 wk, only one apartment in the IPM group had a high level (>12 cockroaches) of cockroach infestation. In contrast, five apartments in the bait treatment group had high level infestations at 29 wk based on overnight trapping counts; thus, IPM is a more sustainable method of population reduction. Sanitation levels in the IPM group significantly improved at 29 wk (n=11) compared with that at the beginning of the study. The sanitation levels in the bait treatment group remained similar throughout the experiment (n=9). The cumulative cost of IPM was significantly higher than that of the bait treatment. The median costs per apartment during 29 wk were 64.8 dollars and 35.0 dollars for the IPM and bait treatment, respectively. The median amount of bait used per apartment in the IPM and bait treatment was 45.0 and 50.0 g, respectively. The cost of the IPM group for the 29 wk service was similar to that of the bait treatment group. We expect that IPM will provide better control at similar cost compared with bait treatment beyond 29 wk.