CO[-/,( ! xrvD^''^ COCKROACH PROOFING Preventive Treatments for Control of Cockroaches in Urban Housing and Food Service Carts R. C. MOORE The Connecticut Agricultural Experiment Station New Haven • Bulletin 740 * December 1973 MK Digitized by the Internet Archive in 2011 with funding from LYRASIS members and Sloan Foundation http://www.archive.org/details/cockroachproofinOOmoor Cockroach Proofing COCKROACH PROOFING Preventive Treatments for Control of Cockroaches in Urban Housting and Food Service Carts R. C. MOORE Introduction The German cockroach, Blattella germanica, is the most important household insect present throughout the year in the United States (Mampe 1972). Infestations in densely populated inner-city areas of Connecticut are serious. A survey taken in 1970, in six New Haven public housing projects, revealed that 60% of the apartments were infested; of lliese, 18% were classified as very heavily infested (New Haven, De- partment of Health, 1970). As people move from infested housing into new low and moderate income housing, they often bring cockroaches with them. If cockroach prevention measures could be taken during construction of a building, they might be safer, more effective, and more economical than present techniques. Several materials provide tlie lengthy residual activity needed for cockroach proofing. Dri-die® and Drione® have been reported to be effective against at least 50 species of arthropods, including seven species of cockroaches (Tarshis 1964). Ebeling et al. (1965, 1967, 1969) and Tarshis (1964), reported on successful use in California of inorganic dusts such as Dri-die 67, Drione, and boric acid for cockroach proofing. Dri-die (95.3% amorphous silica gel and 4.7% ammonium fluosilicate ) , is a nonabrasive, liighly sorptive desiccant dust. It kills by absorbing a portion of the thin protective lipid layer of the cuticle, causing cock- roaches to lose water at a lethal rate. Drione is a mixture of Dri-die (38.12% amorphous silica gel and 1.88% ammonium fluosilicate), pyre- thrins ( 1.0% ) , and piperonyl butoxide ( 10% ) . Drione also acts as a desiccant, but the addition of pyrethrins makes it more toxic than Dri- die, and causes it to kill roaches more rapidly (Ebeling 1971). Cover— Adult female German cockroach with egg case. 4 Connecticut Experiment Station Bulletin 740 Cockroaches are repelled by Dri-die and Drione ( Ebeling et al. 1966, Moore 1972), thus treated areas become less attractive as harborages and breeding places. These same authors have shown that boric acid, which acts as a stomach poison, has been very effective against cock- roaches because it does not repel them. Moore (1972) showed that small amounts of Dri-die 67 or Cab-O-Sil M-5 ( 99% SiOs ) , mixed with boric acid, increased the toxicity of boric acid with little or no increase in repellency. Baygon® (2-iso Propoxyphenyl-methylcarbamate ) 2% roach bait, after having been aged for 101 days, continued to kill more than 90% of the cockroaches exposed in laboratory tests (National Communicable Disease Center, 1971). Baygon 2% roach bait, followed by a 1.1% Bay- gon spray, was used successfully by Moore (1971) to reduce infestations in occupied urban apartments. Cockroaches are not only a problem in urban apartments, but are sometimes abundant in hospitals as well. Unique problems in hospitals are infestations in the insulation of electrically heated food carts and in cracks and crevices of other utility carts used in food service. These carts usually are fogged monthly with pyrethrum, but this method of cockroach control has been unsatisfactory. In this study, boric acid, Dri-die, boric acid plus Dri-die, boric acid plus Cab-0-Sil and Baygon bait, were placed in apartments under con- struction or prior to occupancy to determine their effectiveness in pre- venting cockroach infestations. Drione was evaluated for control in electrically heated food carts and utility carts used in a hospital cafeteria. Materials and Method* Four buildings under construction in a low and moderate income housing project in New Haven were selected for evaluation of inorganic dusts. In building A, with 21 apartments, 11 units were treated with boric acid plus 0.1% Cab-O-Sil M-5; the remaining 10 units were treated with boric acid plus 0.1% Dri-die 67. In building B, 15 units were treated with Dri-die 67 alone. Boric acid alone was used in building C. The nine apartments in building D were not treated. Technical grade boric acid powder (Mallicrodt Chemical) was passed through 16-mesh window screen, before the silica materials, 0.1% Dri-die (FMC Corpora- tion) or Cab-O-Sil (Cabot Corporation), were added. The materials were thoroughlv mixed using a motorized mixer. Cockroach Proofing Figure 1. -Applying dust into wall voids using a pressurized blower. All apartment walls surrounding the kitchen, bathrooms, and utility room were treated (Fig. 1) by blowing dust between the walls with a modified pressurized fire extinguisher (Neil A. MacClean Co.) as de- scribed by Ebeling et at ( 1967). Some difficulties were experienced when applying either boric acid or Dri-die alone. After standing several days, boric acid powder became packed and lumpy. This caused clogging in the hose of the pressurized duster. Clogging was prevented by screen- ing and then sifting the boric acid as it was being added to the duster. Dri-die or Cab-O-Sil are anti-caking agents which prevented lumping of the boric acid. While most of the Dri-die applied in wall voids will adhere to treated surfaces, some of it tends to float around excessively because it is extremely light. This is especially true when it is applied in open areas such as cabinet tops or under appliances. 6 Connecticut Experiment Station Bulletin 740 The construction of the buildings studied was especially suited for this treatment. Dust could be blown throughout the wallspace through a single opening, such as an electrical outlet, because metal studs with a 4" opening every foot supported the wallboards. In walls without elec- trical outlets or other openings, a V^' hole was drilled in the wallboard to inject the dust. Other areas treated with the pressurized duster in- cluded: 1. the basement area through which all common utility pipes ran; 2. the area where heating pipes entered wallspaces; 3. false areas under kitchen cabinets; and 4. enclosed soflfit areas above cabinets. Sev- eral weeks before tenants began to move in, a hand duster (Getz gun) was used to treat other cabinet and closet areas and also under and be- hind kitchen appliances (Fig. 2). Approximately 5 lbs. of boric acid Figure 2.— Applying dust or bait using a Getz-gun hand duster. dusts and 2.5 lbs. of Dri-die were apphed per apartment. After tenants moved into the buildings, the treatments were evaluated by monthly inspections using a pyrethrin aerosol spray to flush cockroaches into the open. Two formulations of Baygon 2% roach bait (Chemagro Chemical Co.) were tested in the laboratory and in the field. Bait A was formu- lated by the manufacturer using technical grade Baygon. Bait B used 50% wettable powder. The efficacy was determined by confining cockroaches to 1 cc deposits in plastic dishes as described by Moore (1972), and calculating the KD50S (knock-down dose for 50%). Re- pellency was tested by giving cockroaches a choice between darkened Cockroach Proofing areas containing bait, and untreated lighted areas (Moore 1972) with food and water. The numbers of living and dead cockroaches in the dark- ened, baited area were recorded at 24 hr. intervals. Field tests with Baygon 2% roach bait were conducted in 30 newly constructed apartment units in New Haven. Half were treated with each bait formulation several weeks before tenants moved in. The bait was formulated as "crevice-sized" particles which could easily be ap- plied with a Getz gun. Treated areas included those under and behind appliances, under radiators, in kitchen cabinet corners, on utility room and closet shelves, in sink cabinets, and in cracks, voids, and other en- closed areas. Wall voids were not treated. Particular attention was given to baiting false areas in and under kitchen cabinets because these pro- vide excellent harborages for cockroaches. Between V2 and 1 lb. was applied per apartinent. Monthly evaluations were made using the pyrethrin flushing technique. Figure 3.— Applying Drione dust to insulation of electrically heated food carts using a Centra-bulb duster. Two types of carts were treated in a state hospital facility. Twenty- five electrically heated food carts and 10 utility carts were treated widi Drione dust (FMC Corporation). Tlie tops of the food carts were re- moved and the dusts were applied to the insulation with a Centra-bulb duster (Fig. 3). Approximately 2 oz. of Drione were used per cart. Ten utility carts (5 large and 3 small metal carts, 1 large and 1 small wooden cart) were also treated using an aerosol can containing Drione. The dust was sprayed on under surfaces of the shelves and into all crevices. Monthly evaluations were made with pyrethrins. Connecticut Experiment Station Bulletin 740 Table I Areas of the apartments where cockroach infestations were most frequently found. % of sites infested Treatment No. apts. Kitchen Bathroom Utility Room Closets Boric acid (BA) 4 75 25 25 0 Dri-die 2 100 50 50 0 BA + 0.1% Dri-die 3 67 33 33 0 BA + 0.1% Cab-O-Sil 8 100 63 25 25 Untreated 5 100 60 0 40 Totals 22 91 50 23 18 Results Boric acid-silica dust treatments. Results are given only for apart- ment units which were occupied for the entire first 6 months evaluation period. The kitchen was the most frequently infested site ( Table 1 ) . As shown in Table 2, boric acid or Dri-die alone, or boric acid plus 0.1% Dri-die were the most eflPective. This was true following 6 monthly in- spections and also at the end of 18 months. In occupied units treated with these dusts, the infestation rate never exceeded more tlian 20%. In units treated with boric acid plus 0.1% Cab-O-Sil, 30-50% were in- fested after 6 months and 60% were infested after 18 months. At least half of the untreated units were infested when inspected the first time. No more than 13 cockroaches were flushed out during any inspection of a treated building, even after 18 months (Table 2). Cockroach Proofing J) bo c •c fcC .S ^3 o bO c W •^ n3 'tS c o B CQ (M ^ I- f— 1 I— ( of in CO CD" CD Ol CD co" of 1— 1 o I— 1 CD CO 1— 1 of Ol CD 2 en CO lO l> Ol ^ «^ Ol C<| TO 1— T ^ r. Ol I-H 00 cd" 0^ CM >-l CD W rH O '-I CO CO ^ Ol ol in CO O <-i O CO Ol O O O O 50 "3 < P5 O 1^3 6 i r-H 1— 1 d d + + < < -H ^ 'H 10 Connecticut Experiment Station Bulletin 740 Baygon bait treatments. Two formulations of Baygon 2% roach bait were evaluated in the laboratory (Table 3). When cockroaches Table 3 Efficacy of two formulations of Baygon bait for German cockroaches when confined with bait or in a choice situation. Baygon bait Formulation KDso when roaches confined with bait ( minutes)" % kill 1 after roaches choice boxes 2 3 initially placed in (days)" 7 9 18 A 59.4 36.7 58.3 75.0 83.3 88.3 91.7 B 34.3 25.0 56.7 65.0 83.3 86.7 88.3 Untreated None 0 0 3.3 8.3 * 3 replicates of 10 adult male German cockroaches. ^ 3 replicates of 20 adult male German cockroaches. were confined with the bait, it took 34 minutes for 50% to be knocked down with formulation B, and 59 minutes with formulation A. In the choice situation, 83% were killed in 7 days with either formulation. After 18 days, about 10% were still alive. The results given in Table 4 show that live cockroaches were not entering darkened baited areas as frequently as the unbaited area. These observations indicate that cockroaches may have been repelled by the bait. Table 4 Percentage of German cockroaches in the dark area of choice boxes treated with Baygon bait formulation. % live insects in dark area on day Baygon bait Formulation 1 2 3 7 9 A 10.5 32.0 20.0 10.0 14.3 B 15.6 19.2 23.8 20.0 12.5 Untreated 43.3 71.7 58.3 77.6 84.5 Cockroach Proofing 11 Numbers of roaches in newly constructed apartments treated with Baygon bait formulations are shown in Table 5. Two of the 15 newly constructed apartment treated with Baygon bait, formulation A, were infested after 3 and 6 months. In units treated with formulation B, one was infested after 3 months and three after 6 months. Table 5 Effectiveness of two foraiulations of Baygon bait for controlling German cockroaches when buildings were treated prior to occupancy. Baygon bait Formulation No. apts. No. infested apts. after 3 6 months months No. roaches flushed after 3 6 months months A 15 2 2 1,12 6,25 B 15 1 3 3 1, 4, 25 Drione dust treatments in food caHs. The application of Drione dust to electric food cart insulation reduced the numbers of roaches in the carts by 98% after 1 month (Table 6). It continued to control at approximately this level for 5 months. In utility carts treated with the aerosol, roaches were reduced by 76% after 1 month and by 95% after 3 months. Table 6 Effectiveness of Drione dust for controlling German cockroaches in electrically heated food carts and other utility carts. Treatment Initial No. roaches (carts) % reduction after 1 month 3 months 5 months Drione dust 135 (25)'' 97.8 98.5 96.3 Drione aerosol 210(10)" 76.2 95.2 - ^ Electrically heated food carts. "^ UtiUty carts. 12 Connecticut Experiment Station Bulletin 740 Discussion These field tests show that appHcation of dusts such as Dri-die, Cab-O-Sil or boric acid and Baygon bait to apartments under construc- tion were a successful control measure. There are several advantages to treating buildings during construction or before occupancy: 1, Insecti- cides are safer to apply when units are uninhabited; 2. treatments can be more thoroughly applied to areas such as cabinets or closets because they are empty; 3. tenants are not present to interfere with the ap- plicator; and 4. dust or bait may keep cockroaches brought in by tenants from getting established. Drione dust applied to food and utihty carts successfully reduced roaches. It might be advantageous to treat these carts during construc- tion. Applications of Drione dust to the insulation of other electric ap- pliances such as stoves, refrigerators or freezers might also be effective in reducing cockroach infestations. Dusts and baits are normally used as secondary or back-up treat- ments for residual sprays, but these data shows these materials can be used as the primary control measure. Dusts have a longer residual hfe than sprays, they penetrate deeper into cockroach harborages, and brief contact with the dust leaves a lethal deposit on roaches. Baygon bait, because of its "crevice-size," can be applied directly to the insect harborage. Acknowledgment The cooperation of the Keystone Exterminating Co. is gratefully acknowledged. Cockroach Proofing 13 Reference Cited Ebeling, W. 1971. Sorptive dusts for pest control. Ann. Rev. Entomol. 16: 123-58. Ebeling, W., R. E. Wagner, and D. A. Reierson 1965. Cockroach control with Dri-die and Drione. P.C.O. News 25(10) : 16-22. EbeHng, W., R. E. Wagner, and D. A. Reierson. 1966. Influence of repellency on the efficacy of blatticides. I. Learned modification of behavior of the German cockroach. J. Econ. Entomol. 59(6): 1374-88. Ebeling, W., R. E. Wagner, and D. A. Reierson. 1967. Pressurized powder blower for applying boric acid. P.C.O. News 27(2): 4-6, 10, 23. Ebeling, W., R. E. Wagner, and D. A. Reierson. 1969. Insect proofing during build- ing construction. CaUf. Agr. 25(5): 4-7. Mampe, C. D. 1972. The relative importance of household insects in the continental United States. Pest Control 40( 12) : 26-27, 38. Moore, R. C. 1971. Chemical control of German cockroaches in urban apartments. Conn. Agr. Exp. Sta., New Haven, Bull. 717: 1-11. Moore, R. C. 1972. Boric acid-silica dusts for control of German cockroaches. J. Econ. Entomol. 65(2): 458-61. National Communicable Disease Center. 1971. Public health pesticides: cockroaches. Pest Control 39(3): 44-45. New Haven, Department of Health. 1970. Vermin control demonstration program final report— How to control them. 93 pp. Tarshis, I. B. 1964. The use of the silica aerogel insecticides, Dri-die 67 and Drione, in new and existing structures for the prevention and control of cockroaches. Laboratory Animal Care. 14(3): 167-84. 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