Fig. 2

POPULATION
AND
COMMUNITY ECOLOGY
Status of Urban Bed Bug Infestations in Southern China: An
Analysis of Pest Control Service Records in Shenzhen in
2012 and Dongguan in 2013
LEI WANG,1 XUQUAN CAI,2 AND YIJUAN XU1,3
J. Med. Entomol. 52(1): 76–80 (2015); DOI: 10.1093/jme/tju015
ABSTRACT The recent resurgence of bed bugs (Cimex spp.) in many developed countries has drawn
increasing attention worldwide. The status of urban bed bug infestations were investigated in Shenzhen
and Dongguan, two major cities in southern Guangdong Province of southern China, based on pest control service records from two different companies (one during 2012 and another during 2013). The results showed that Shenzhen and Dongguan have a severe problem with bed bug infestations: the control
of bed bugs is a constant concern, except during the winter. In Shenzhen, a similar number of premises
were treated for bed bugs in central business districts and suburban districts. However, in Dongguan,
more premises were treated for bed bugs in suburban districts than in central business districts. The
treatment rate for worker sleeping quarters, apartments, hotel, and private houses in Shenzhen was 53.8,
43.0, 1.9, and 1.3%, respectively. The percentage of treated rooms was 56.1% for worker sleeping quarters and 91.1% for apartments. In Dongguan, the treatment rate for worker sleeping quarters, apartments, hotel, and private houses was 90.0, 10.0, 0.0, and 0.0%, respectively.
KEY WORDS Cimex spp., infestation, treatment record, seasonality
Introduction
Bed bugs are significant pests of humans with a history
that dates back to ancient times (Romero et al. 2007).
These insects include the bed bug, Cimex lectularius
L., and the tropical bed bug, Cimex hemipterus F.
(Usinger 1966). They are mainly active at night and
feed on human blood. Biting by bed bugs can cause
red itchy welts (Kolb et al. 2009) and severe iron deficiency anemia due to blood loss (Pritchard and Hwang
2009). Fortunately, there is no clear evidence to date
that bed bugs can transmit disease-causing organisms
(Delaunay et al. 2011). Bed bugs can also adversely affect mental health; bed bug infestations often are associated with sleep disturbance and symptoms of anxiety
among humans (Susser et al. 2012).
Bed bugs nearly disappeared in developed countries
during the 1940s and 1950s principally because of the
use of residual insecticides (Romero et al. 2007), but
these pests made a comeback worldwide in the late
1990s (Doggett et al. 2004, Boase 2008). Bed bugs
were found to have infested 30% of the homeless
shelters in Toronto, ON, Canada, in 2003 (Hwang et al.
2005). The resurgence of bed bugs resulted in estimated economic losses of AUS$100 million in Australia
(Doggett and Russell 2008). Insecticide resistance is
1
Department of Entomology, South China Agricultural University,
483 Wushan Rd., Guangzhou, 510642 China.
Shenzhen Yili Pest Control Co. Ltd, 1279 Hongling Zhonglu,
Shenzhen, 518022, China.
3
Corresponding author, e-mail: [email protected].
2
the key trigger behind the resurgence of bed bugs, and
the resistant bed bugs spread around the world
through the increasing mobility of the human population and poor pest management practices (Davies
2012, Doggett et al. 2012). Knowledge on the ecology
and biology of bed bugs is essential to devise ways to
effectively control the species (Doggett et al. 2004,
Reinhardt and Siva-Jothy 2007, Weeks et al. 2011,
Khan and Rahman 2012, Saenz et al. 2012). There
have been numerous reviews on pesticide efficacy and
new management technologies to more effectively control bed bug infestations (Moore and Miller 2009, How
and Lee 2011, Lehnert et al. 2011), and the development of industry standards that promote sound bed
bug management practices for bed bug eradication
(Madge 2012, Doggett 2013, the U.S. National Pest
Management Association [NPMA] BMP Bed Bugs
Best Management Practices 2011). The transcriptomics
of C. lectularius have been studied to provide clues in
identifying genes involved in pesticide resistance (Bai
et al. 2011, Mamidala et al. 2012).
Bed bugs became uncommon in Mainland China
during the 1950s, and they currently are not a significant concern throughout China (Wang and Wen 2011).
However, a survey in 2012 indicated that bed bugs had
undergone a potential resurgence in China with bed
bug infestations becoming common in the Pearl River
Delta of southern China (Wang et al. 2013). A better
understanding of the magnitude of the resurgence
should be the first step to combat bed bugs (Doggett
and Russell 2008). Compared with other countries, scientific reports relating to bed bugs are lacking in China.
C The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America.
V
All rights reserved. For Permissions, please email: [email protected]
January 2015
WANG ET AL: STATUS OF URBAN BED BUG INFESTATIONS IN SOUTHERN CHINA
Hunan
Jiangxi
77
Fujian
Guangxi
Dongguan
Guangzhou
Macau
Shenzhen
Hongkong
Guangdong province map
Fig. 1. Geographic locations of Shenzhen and Dongguan. Shenzhen and Dongguan are two large cities of Guangdong
Province in southern China.
We surveyed bed bug treatment data from a pest control company in Shenzhen and another in Dongguan
for 2012 and 2013, respectively. Shenzhen and Dongguan are two adjacent industrial cities in the Pearl River
Delta, and their population is largely comprised of migrant workers from villages or small towns throughout
China. The data were analyzed to document the extent
of bed bug infestations in southern China.
Materials and Methods
Pest Control Service Records. Shenzhen and
Dongguan are two large cities of Guangdong Province
in southern China, geographic locations of the cities
are shown in Fig. 1. There are 1,000 PCO companies
in each of these two cities. According to our random
preliminary survey of 11 PCO companies in Shenzhen
and Dongguan, 35% of pest treatment services in
these POC companies involved bed bug. The data used
for analysis in this study were obtained from the Shenzhen Yili Pest Control Co. Ltd. (a medium-sized PCO
company in Shenzhen) and Dongguan Xinxiwang Pest
Control Co. Ltd. (one of the largest PCO companies in
Dongguan). The data detailed information on the number of bed bug treatments, including the treatment
date, structure type, and the number of infested rooms.
Treated premises were categorized as 1) worker sleeping quarters (residences provided by industrialist for
migrant workers; they consisted of a series of single
rooms); 2) apartments (residences rented by tenants,
and apartments that have more than one room and that
only consisted of a bedroom and a living room); 3)
hotels (hotels and motels); and 4) private houses (privately owned apartments or houses). Both pest control
companies identified the bed bug to the genus Cimex
in every treatment, but they did not collect and preserve the specimens in every bed bug incidences. Deng
and Meng (1953) indicated C. hemipterus was the
dominant species in Guangdong Province based on
examined specimens. Because bed bug specimens were
not available from every bed bug treatment, we did not
know whether or not both C. lectularius and C. hemipterus were involved in these treatments, although all
the specimens we checked are C. hemipterus. Thus, we
use the genus Cimex in this article.
Results
In total, 373 sites were treated for pests in Shenzhen
by Yili Pest Control Company in 2012, and 158 of these
involved bed bugs. Of the 893 total sites treated for
pests in Dongguan by Xinxiwang Pest Control Company in 2013, 261 sites involved bed bugs. In Shenzhen
in 2012, no bed bug treatments were performed in January and February, with two treatments performed in
March (Fig. 2A). The number of premises that needed
bed bug control greatly increased thereafter and
remained at a high level from June to October, and
78
JOURNAL OF MEDICAL ENTOMOLOGY
Fig. 2.
Vol. 52, no. 1
Number of bed bug treatments per month: (A) in Shenzhen in 2012 and (B) in Dongguan in 2013.
then decreased from November to December. The
largest number of treated premises (28) was in August.
In Dongguan, in 2013, the number of premises that
needed bed bug control showed a similar trend
(Fig. 2B). No bed bug treatments were performed in
January and only five premises were treated in February. Thereafter, the number of treated premises greatly
increased, peaking in September. Treatments subsequently decreased and only five premises were treated
for bed bugs in December.
In Shenzhen, a similar number of premises were
treated for bed bugs in central business districts
(70 premises) and suburban districts (88 premises).
However, in Dongguan, more premises were treated
for bed bugs in suburban districts (219 premises) than
in central business districts (42 premises). In Shenzhen,
bed bug treatments were conducted in four types of
residential structures, including worker sleeping quarters (53.8%), apartments (43.0%), hotels (1.9%), and
private houses (1.3%). In contrast, in Dongguan, no
bed bug treatments were conducted in hotels and private homes; instead, worker sleeping quarters
accounted for most of the treatments (90.0%) and
apartments were a minor component (10%). In Shenzhen, 91.1% of all rooms in those apartments treated
were infested, and the room infestation rate in those
January 2015
WANG ET AL: STATUS OF URBAN BED BUG INFESTATIONS IN SOUTHERN CHINA
worker quarters treated was 56.1%. Similarly, in Dongguan, 83.7% of all rooms in those apartments treated
were infested; 61.2% of all rooms in treated worker
quarters were infested.
Discussion
This investigation indicates that bed bugs are a serious problem in Shenzhen and Dongguan, evidenced by
two pest control companies reporting that 42.4 and
29.2% of their pest cases involved bed bugs in these
two industrial cities, respectively. Bed bug treatments
were conducted year-round, but were minimal in winter months. Bed bug treatment rates were similar
between central business districts and suburban districts in Shenzhen, but more treatments were conducted in suburban districts than central business
districts in Dongguan. Apartments and worker sleeping
quarters had higher treatment rates than hotels and
private homes. There was no difference in the number
of bed bug treatments between worker sleeping quarters and apartments in Shenzhen. However, in Dongguan, more treatments were conducted in apartments
than in worker sleeping quarters.
In 2011, the population of Shenzhen was 10.46 million with a transient population comprising 74% (7.78
million; Statistical Communique on the 2011 National
Economic and Social Development of the city of
Shenzhen, Shenzhen Municipal Bureau of Statistics).
In 2012, in Dongguan, the population was 8.29 million,
with a transient population comprising 78% (6.42
million; Statistical Communique on the 2011 National
Economic and Social Development of the city of Dongguan, Dongguan Municipal Bureau of Statistics).
Approximately 9.72 million people left Shenzhen for
the spring festival holiday from 8 January to 16
February 2012 (Shenzhen Evening Newspaper, 29
December 2011); in Dongguan, approximately 7.62
million people left for the spring festival holiday from
26 January to 26 March 2013 (Dongguan Daily Digital
Newspaper, 9 March 2013). Most of these holiday travelers are migrant workers. Our survey showed that
worker sleeping quarters and apartments were the two
most common structures treated for bed bugs, and
most residents of apartments and worker sleeping quarters are migrant workers. Thus, we speculate that
migration of people might be related to the decline in
the number of bed bug treatments during the winter in
Shenzhen and Dongguan. Mabud et al. (2014) also
mentioned that the yearly nadir in bed bug reports in
December may occur because of increased travel during the holidays or because the Department of Public
Health’s Vector Control Service is briefly closed during
the holiday season.
Private houses, apartments, hotels, and worker sleeping quarters in southern China are the most common
places infested by bed bugs (Wang and Wen 2011).
Similar phenomena also plague Toronto, ON, Canada
(Hwang et al. 2005), Australia (Doggett and Russell
2008), and the United States (Potter et al. 2008). Notably, however, only 3.2 and 0.0% of bed bug treatment
sites were private houses and hotels in Shenzhen and
79
Dongguan, respectively, whereas treatment rates
reached 70.0% for private houses in single-family
dwellings in Toronto, ON, Canada (Hwang et al. 2005).
Possibly, prompt detection and treatment in southern
China may have contributed to the observed phenomenon. Nevertheless, treatment rates in Shenzhen apartments and worker sleeping quarters were 43.0 and
53.8%, respectively. In Dongguan, apartments and
worker sleeping quarters, the treatment rates were 10.0
and 90.0%, respectively. Increased urbanization and
industrialization has produced a large transient population in China, which may facilitate the spread of bed
bugs. Apartment tenants may conceal bed bug infestation information for fear of financial penalties or eviction (Moore and Miller 2009). Industrialists are often
not willing to pay additional costs for pest control.
These reasons may have contributed to high infestation
rates in apartments and worker sleeping quarters in
Shenzhen and Dongguan.
This study suggests that the severe bed bug infestations in Shenzhen and Dongguan primarily afflict
migrant workers from villages or small towns throughout China. Fortunately, bed bugs currently are not a
significant concern in other places in China (Wang and
Wen 2011). Based on our data, bed bug treatments in
migrant worker sleeping quarters is very high; bed
bugs are likely to spread into other areas as migrant
workers travel (Wang and Wen 2011). Therefore, the
local government of Guangdong Province needs to
monitor this issue to prevent bed bugs from spreading
and to ensure that infestations are properly managed.
Effective methods following an integrated pest management approach and accepted industry management
standards adopted in Europe, the United States, and
Australia should be used to decrease bed bugs infestation rates in key areas, such as apartments and worker
sleeping quarters. Educating residents on how to minimize the transmission of bed bugs is critical for reducing their spread. Adopting these measures would go a
long way toward slowing the spread of bed bugs
throughout the nation.
Acknowledgments
We thank Dr. Jian Chen from United States Department of
Agriculture–Agricultural Research Services and Dr. Virna
Saenz from North Carolina State University for critical
reviews of an early version of the manuscript. We would like
to thank two anonymous reviewers for many helpful comments on the manuscript. This study was supported by the
Science Foundation for The Excellent Youth Scholars of
Guangdong Province (No. Yq2013031) and partly supported
by Hesheng Zhujiang Education Foundation from South
China Agricultural Univeristy.
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