Brownbanded cockroach Allergy and asthma overview
Public Health Significance of Urban Pests
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times. This might provide a useful monitoring tool in situations where brownbanded cockroaches are a problem.
2.2. Health hazards 2.2.1. Surveys and public opinion
Cockroaches typically rank as one of the most common and objectionable insects encoun- tered by homeowners, especially in low-income housing. In a survey of 315 inner-city
and low-income women in New York City, 66 of them reported seeing cockroaches Whyatt et al., 2002. Greater than 75 of apartment tenants considered cockroaches a
serious problem Wood et al., 1981. In three cities in the eastern United States – Baltimore, Roanoke, and Norfolk – surveys of tenants of public housing indicated that
83 felt that cockroaches were a serious problem Zungoli Robinson, 1984. Cockroaches were more important than other negative factors in these buildings, such as
leaky faucets, broken windows and trash in the yard. Only the presence of mice was considered worse. In a similar study of London residents, more than 80 of the residents
from uninfested apartments felt that cockroach infestations were worse than poor secu- rity, dampness, poor heating and poor repair Majekodunmi, Howard Shah, 2002.
Again, only infestations of mice were considered worse. Residents with cockroach infes- tations were slightly more tolerant of the problem than residents that did not have coc-
kroaches. Only 2 of the respondents mentioned asthma or allergies as a potential health concern associated with cockroaches. A survey by Davies, Phil Peltranovic 1986 of
apartment residents in Toronto, Canada, indicated that about 50 of them had cockroach infestations, 89 considered them a health hazard and 94 considered them a source of
anxiety. In a household survey in Kentucky, 63 of the respondents listed seeing 0 to 1 cockroach as their tolerance threshold. Less than 10 of the respondents would tolerate
seeing more than five cockroaches Potter Bessin, 1998.
In addition to the direct health problems associated with cockroaches such as allergic responses, transport of pathogenic organisms and contamination of food, improper appli-
cations of insecticides and a heavy reliance on aerosols and the application of liquid sprays to surfaces may create potential human exposure problems. More than 90 of the pesti-
cides applied in apartments are directed at cockroaches Whyatt et al., 2002. Fischer and colleagues 1999 reported several cases in sensitive areas, such as schools and health care
facilities, where house dust contained detectable amounts of the pesticides pyrethrum, piperonyl butoxide, chlorpyrifos and cyfluthrin. Three insecticides, acephate, chlorpyri-
fos and propetamphos, were detected on both target and non-target surfaces in schools treated for cockroach infestations Williams et al., 2005. In apartments infested with
German cockroaches, air samples of the residences n = 60 found that more than four pesticides used for cockroach control were present. In 18 of 60 cases, eight different pes-
ticides were detected in the air, clearly suggesting an over-reliance on chemical measu- res to control cockroaches in these housing units. No explanation was given for the pos-
sible source of the dichlorodiphenyltrichloroethane DDT and chlordane found in air samples Whyatt et al., 2002.
Cockroaches
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and whitish first two abdominal nota the dorsal parts of the first two abdominal seg- ments. Compared with other outdoor species, the ootheca is large Fig. 2.4.
Outdoors, smokybrown cockroaches are likely to be found in woodpiles, bark, leaf mulch, tree holes, planters and utility vaults. They feed on fruit, dead insects, worms and
pet food. They will infest water-meter boxes, but are rarely found in sewer systems. Smokybrown cockroaches will occasionally invade structures; however, sustained indoor
breeding populations are rare. The proximity of preferred habitats close to homes is responsible for domestic infestations Brenner Pierce, 1991. Catches in indoor traps
positively correlate with outdoor catches Smith et al., 1995. Preferred indoor harbou- rages include empty spaces of porch and carport ceilings, exterior walls of furnace rooms
and empty spaces of water damaged walls Appel Smith, 2002.
Like the oriental cockroach, the smokybrown cockroach has a restricted small outdoor home range less than 280 m
2
and restricted movements near harbourages, such as under decks and within debris that offers dark hiding places Appel Rust, 1985. Traps or baits
in these areas dramatically reduce populations, eliminating the need for perimeter spraying. The incidence of smokybrown cockroaches in urban habitats has led to the development
of a cockroach habitat index Smith et al., 1995. Such factors as the number of trees, pets, residents, age of the house and the obvious cockroach harbourages were the most impor-
tant indicators of infestation. Such items as mulched and bushy landscapes next to retai- ning walls and sheds are especially attractive. The index can help target sites for a com-
prehensive IPM programme, including insecticide treatment and habitat modification.
The volatile sex pheromone of the smokybrown cockroach has been isolated and identi- fied as periplanone D Takahashi et al., 1995. It elicits low activity in American coc-
kroach, in Periplaneta japonica and in oriental cockroach males. Periplanone D may prove useful in monitoring traps, especially since smokybrown cockroaches are less likely to be
trapped than American cockroaches.