Bedbugs belong to the genus Bedbugs, Hemiptera, Bedbugs family, Bedbugs genus, which is a group of medically important insects in Hemiptera. According to reports, there are 74 species of bedbugs in the world, but most of them are parasitic on bats and birds, with fewer species related to humans.

Bedbugs are also known as ticks, ticks, bed ticks, roaches and so on.

The Japanese call bedbugs “Nanjing bugs” in Japanese, which we feel really wronged, because bedbugs are neither unique to Nanjing nor to China, but only indicate that the Japanese not only brought back advanced cultural resources from China, but also brought back bedbugs.

Bedbugs have a pair of odor glands between the bases of the second and third pairs of feet in the chest. They secrete an unusual odor liquid that protects against natural enemies and promotes mating. Bedbugs are called bedbugs because they leave an unpleasant odor where they crawl.

Bedbugs became the bomber’s navigator during the Vietnam War. Bedbugs were also sent to war during the Vietnam War. In the spring of 1972, the United States launched the Battle of Guard One. North Vietnam sends ammunition to its southern comrades through the hidden Ho Chi Minh Trail, They are usually worried about the air strikes by US planes, because US military planes have parachuted many “bug scouts” carrying pico-radio transmitters into the jungle, and when the bugs scent sweat and crawl onto Vietnamese officers and men to suck blood, the transmitters on their backs send signals, and US bombers bomb them according to the signals emitted by the bugs.

1    Morphological characteristics of bedbugs

1. The adult body is flat, oval, reddish brown, 4 ~ 5 mm long, 3 mm wide and 0.5 mm thick. Females are slightly larger than males.
   1. Egg oval, about 1 mm long, with egg cap, egg white, egg shell with obvious reticulate pattern. Often glued to cracks and rough surfaces.
   1. The nymphs of the newly hatched and newly molted nymphs are pale brown, then darker. The nymphs resemble adults and have similar habits. The nymphs are small in size, immature in sex and lighter in color. They can suck blood and emerge as adults after 5 molts (Fig. 1).

2    Common species of bedbugs

There are only two species of bedbugs closely related to humans, namely, temperate bedbugs and tropical bedbugs. Temperate bugs are more adaptable and distributed all over the world, while tropical bugs require higher temperatures and do not thrive except in the tropics. Temperate bedbugs are distributed all over China, mainly in the north of the Yangtze River. The distribution of tropical bedbugs is limited to cities south of the Yangtze River such as Guangxi, Guangdong, Fujian and Taiwan.

The morphology of the two bedbugs is similar, and the main difference lies in the shape of the forethorax (Fig. 2): the forethorax of the temperate bedbugs is concave deep, and the horns on both sides are wide; Tropical bedbugs have shallow forechest recesses and narrow bilateral corners.

3    Life history of bedbugs

Bedbugs are incomplete metamorphoses, and their development can be divided into three stages: egg, nymph and adult (Fig. 3).

• The eggs produced by the egg bedbugs are firmly adhered to the board cracks, wall cracks, bed cracks or wallpaper wrinkles by means of accessory gland secretions. The initial eggs were milky white and gradually turned yellow, and 5 ~ 6 eggs were piled. The egg stage was affected by temperature: 35 ~ 37 ℃ for 5 ~ 6 days; 22 to 26 DEG C for 8 to 9 day; 16-19

℃ for 21 ~ 22 days; No incubation below 7 ℃.

• The nymph sucks blood from the egg corona for 6 ~ 9 min each time, while the nymph sucks blood from the egg corona. It resembles an adult, but it is small and has no wing base, and its reproductive organs are not fully developed. The nymphs were divided into 5 instar, and molted once every 4 ~ 6 days, and then 5 times after feeding on the nymphs. The nymphs were divided into 5 instar, and the nymphs were molted once every 4 ~ 6 days on average. The nymphs are yellow and white at first, and the individuals become larger and darker with the growth of instar, and finally turn red-brown, and it takes about 20-30 days for them to develop into adults.
  • The adult nymph develops into an adult and mates after 1-2 days. The female nymph sucks blood and lays eggs 3-4 days after mating. The adult nymph develops into an adult and lays eggs from the egg.

The adult can reproduce 5 ~ 6 generations a year (about 3 ~ 4 generations in cold area) under suitable temperature (35 ~ 37 ℃) for about 35 days. The adult life span is about 1 year.

The complete life cycle of bedbugs is mainly determined by ambient temperature, and the development time of bedbugs varies greatly at different temperatures (Table 1).

Table 1 life cycle of bedbug at different temperatures

	Life cycle (d)
Temperature (℃)	Egg stage		Life History Full Period
28	5.5		31.0
25	7.1		34.2
23	9.2		46.0
18	20.2		61.6
15	34.0		125.2
13.	48.7		236.7
7.	Non-hatching		Incomplete

4    Bedbug ecological habit

• Blood-sucking females, males and nymphs all suck blood, and the time of blood-sucking is mostly at night. Blood suction can secrete an alkaline saliva through the mouth injected into the human body to prevent blood coagulation. This kind of saliva has irritation to the human, causes the sting spot to be red, swollen and itchy. After hatching, the nymphs can suck blood for 6-9 minutes each time. Bedbugs are gluttonous, sucking more than 1-2 times their body weight, usually every 24-48 hours. The adult sucks blood for about 10-15 minutes at a time. When sucking blood, it usually does not crawl on the skin, but stops on the bedding, clothes or furniture immediately adjacent to the skin.
  • Hungry bugs As we all know, lice live on the human body, it does not leave the human body, at any time to suck blood. Bedbugs, on the other hand, approach the human body only when they are sucking blood, and leave when they are full. If the bug has no chance to meet people, it will have to starve. In the lower temperature and higher humidity environment, the adult usually can endure hunger for 6-7 months, even more than 1 year. Nymphs can also be hungry for more than two months.
  • Oviposition females lay 2-8 eggs a day, 6-50 eggs in a lifetime. The total number of eggs laid can reach 200-300, and the maximum number can reach more than 500. The egg is attached to the surface of the spawning site after laying.
  • Activity Regularity Bedbugs are afraid of light, mostly at night, but can also suck blood during the day. Bedbugs are quick and alert. When sucking blood, if the human body moves slightly, it will stop sucking blood, crawl away and hide. Bedbugs can crawl 1 ~ 1.25 m per minute. Bedbugs like to live in groups and can be scattered around with clothes and luggage.
  • Habitat bedding insects mainly inhabit the indoor bedstead, tents four corners, walls, ceilings, bedding, straw mattress, mattress and other cracks behind the wallpaper. Bedbug habitats often contain many brown traces of excrement.
  • Seasonal fluctuation of bedbugs is very active in summer and reproduction is vigorous. The optimum temperature and relative humidity of bedbugs are 28 ~ 33 ℃ and 55% ~ 60%, respectively.

Temperate bedbugs usually begin to be active in May, with the highest number in August, fewer after October, and cessation of activity and oviposition in winter.

5    Bedbug investigation method

• The number of bedbugs captured by man-hour method was × 4, calculated as 15 minutes per person at each point. Unit: only/man-hour. Because individuals catch bedbugs at different speeds, it is best to have regular investigators for comparison before and after.
  • Unit area counting method selects a certain number of beds, walls and other surfaces, per square metre of surface, the number of bedbugs found or captured as a density. Unit: only/m2.
  • The bedplate vibration method moves the bedplate to a clean and level ground. The two men raise the bedplate 1m above the ground, then suddenly lower it and vibrate it repeatedly until no bedbugs fall. Counting the number of bugs shocked is the density, in units of one bed per board.

• Trace examination is used to check the walls of dormitories, wards, and hotel rooms for bedbug droppings or blood to determine bedbug presence.
  • The method of investigation and inquiry goes deep into the house and dormitory to ask the occupants if they have found any bug activity, bite, and look at the place where the bug is bitten to determine whether there is bug bite or not, so as to determine whether there is bug or not.
  • In the past, trained inspection dogs were widely used to check drugs, track fugitives and find explosives. Now, countries such as the United States and Australia have used inspection dogs to check for bedbugs. Although the examination results are mainly affected by the dog’s attention, the location of bedbug hiding, ambient temperature and air flow, the dog’s sense of smell is far beyond the visual range, so the dog’s sensitive sense of smell can make up for the shortcomings of visual inspection.

Studies have shown that when the number of bedbugs is very small (only one bug was placed in the experiment), Even if the host had not detected bedbug bites or hidden in invisible crevices, trained inspection dogs could detect bedbugs from Blattella germanica, Reticulitermes occidentalis and Toxodon florida. The positive rate was 97.5% and the false positive rate was 0.

Trained examination dogs could also distinguish live bedbugs and eggs from dead bedbugs, molting and excreta, with a positive indicator rate of 95% and a false positive rate of 3% for bedbug excreta.

In addition, the efficiency of inspection dogs is much higher than that of professional inspectors. For example, routine inspection of a standard room takes at least 15 minutes for professional inspectors and 2 ~ 3 minutes for inspection dogs. Inspection of 250-seat theatres and dogs takes 20 minutes to detect 100% of the hidden bugs and eggs.

Therefore, it is more practical and efficient for inspection dogs to locate bedbugs in laundry rooms, theatres, convention venues, schools, office buildings and public transport than visual inspection.

6    Reasons for reignition of bedbugs

In recent years, bedbugs, which have been extinct for a long time in developed countries such as Europe and the United States, have re-emerged, wantonly attacking human beings in homes, apartments, hotels (including luxury hotels), hospitals, schools, cinemas, airplanes, trains and cruise ships, which have a tremendous impact on human life and economic development.

Bedbugs were barely seen in British cities 20 years ago, but they have not only reappeared in recent years, but are growing rapidly. The number of bedbugs in some parts of London has increased more than tenfold since 1996. After the Sydney Olympics in 2000, bedbugs were found in almost all restaurants in Sydney. The number of bedbugs increased eightfold between 2001 and 2004. New York has been hit by bedbugs, especially since their “resurrection” began in 2004, at an alarming rate. From New York to Chicago, from shelters to fancy hotels, bedbugs keep you awake at night. The National Pest Management Association says reports of bedbugs have quintupled in the past four years. About 300 people attended a two-day “bug summit” on April 14, 2009 at a hotel on the outskirts of Arlington to discuss ways to eradicate the bug, AP reported.

Qingdao Jiaodong online network reported Aug. 7, 2007: Recently, a company staff in our city with a body shape

Flat, reddish-brown, about 5mm long bugs came to the city’s CDC for help, saying many of its employees were bitten by the insect in their dormitories and itched hard to bear. It was identified by vector biologists as a temperate bug that had been extinct in the city for many years, sucking human and animal blood.

In addition, on February 18, 2002, a lawsuit caused by a small bedbug in Lanzhou, Gansu Province, was stirred up. The plaintiff was Wang Yihui, chief engineer of the Gansu Academy of Architectural Sciences, and his wife, Sun Dongmei. The defendant was the Lanzhou Railway Branch Bureau. The plaintiff’s compensation for moral damages was only 1 yuan per person.

CDC, Chaoyang District, Beijing: There are bedbugs in Aobao Hotel.

Experts believe that bedbugs are rampant mainly due to the following reasons: First, people frequently travel abroad for holidays (and often move), bedbugs are particularly susceptible to spread with the activities of people. Second, bedbugs are resistant to common insecticides, resulting in mass reproduction. Third, it is related to the acquisition and use of used furniture and equipment, through which bedbugs migrate and spread. Fourth, it is particularly difficult to control and eradicate bedbugs in poor areas. In these areas, people are often reluctant to discard bedbug furniture or buy pesticides. Fifth, cockroach bait instead of insecticide spraying. Sixth, there is insufficient public awareness of bedbugs and the lack of experience of pest control personnel to control bedbugs in a timely and effective manner. For these reasons, we should attach great importance to the pest control professionals.

7    Bedbug Hazard Pattern

• Potential vectors Although bedbugs have long been suspected of transmitting more than 40 human diseases, there is little evidence that they are biological or mechanical vectors. In addition, although bedbugs can be experimentally infected with a variety of pathogens, it has not been proven that bedbugs can transmit diseases under natural conditions, nor have there been reports of infection caused by bedbug bites, and it seems that sufficient evidence needs to be accumulated before conclusions can be reached.
  • Because of the different impacts of bedbugs on human and environment, different control measures have been taken, and there is no uniform and accurate calculation method to estimate the socio-economic impact of bedbugs. In hotel services, for example, the economic losses caused by bedbugs usually include increased washing costs, replacement of furniture and bedding, thorough cleaning and renovation of rooms, reduced revenues from negative media coverage, and related costs arising from claims and litigation.

In Toronto, Canada, in 2004 alone, at least 17 shelters were treated for bedbug infestation at an average cost of $3,085 per shelter; Costs associated with bedbug-related litigation range from $20 to $38,500. In a 2006 lawsuit in the United States, a woman claimed $2 million from the motel for a severe bug bite during her stay. 2006

An Australian study in # estimated the impact of bedbugs on Australian tourism at 75 to 95 million Australian dollars per year

• Blood-sucking harassment bedbug is a common hazard to human beings, blood-sucking harassment. Most people suffer from itching after being bitten by bedbugs, and some suffer from red swelling that persists for several days. In addition, India has reported severe bedbug infestation with iron deficiency anemia and reports that bedbug faeces may cause asthma.

According to the investigation in our country, bedding is the most serious infestation of indoor furniture. It is noteworthy that the damage caused by bedbugs in our country has been controlled at a very low level for a time due to the improvement of the living standard of our people, the improvement of housing conditions and the application of effective drugs against bedbugs. However, in recent years, there has been a revival trend, especially in prisons, detention centers, migrant workers’ dormitories and so on.

8    Advances in bedbug control

In recent years, many media and professional materials have shown that bedbugs are once again harmful to human beings, and bedbugs are still one of the serious pests. This phenomenon, like other vector organisms, is the result of global warming and changes in the ecological environment. Therefore, it is still of great significance to carry out in-depth research on bedbug control.

During the 1950s and 1960s, many areas were affected by bedbugs in China. At that time, bedbug control was more popular among the people. Organized bedbug control, Beginning in the late 1970s, Especially after the establishment of the scientific research and control group of cockroach bedbugs in 1979, the group has carried out the bedbug control work mainly by general survey and general treatment in the whole country, and has made gratifying achievements and rich experience, and Nanjing, Shanghai, Hangzhou, Harbin, Wuhan and Changsha, many cities have stepped into the ranks of the advanced bedbug control urban areas named by the National or provincial AIDS Committee.

However, bedbugs can survive even without bloodsucking throughout the year, reproduce at an alarming rate, can hide anywhere, and develop resistance to commonly used insecticides, making prevention and control difficult for even professionals. An online survey in the United States

The results showed that 58% of the professionals believed that bedbugs were the most difficult to control, followed by ants (24%) and cockroaches (14%), and there was no cure for bedbugs.

• The principle of controlling bedbugs is to arouse the masses, take comprehensive measures and carry out the control over and over again. Second, we must be comprehensive, meticulous and thorough.
  • The purpose of environmental prevention and control is to eradicate breeding conditions. A large number of practical experience has proved that the management of bedbug encroachment sites, environmental treatment is particularly important. Bedbug control efforts, whether in urban or rural areas, should be integrated with local health creation efforts.

In the city, it is necessary to carry out evaluation and comparison activities for various collective and migrant workers’ dormitories to create the “cleanest dormitory”, so as to frequently dry bedding, frequently bathe and change clothes, so that there are no sundries at the bedside and under the bed, and there is no odor in the dormitory.

In rural areas, we should combine the construction of a new countryside, carry out activities to change customs with clean and hygienic kang, beds, and bedrooms, and with bright and ventilated.We can use putty, gypsum, and cement to plug the cracks in walls, ceiling grilles, and various sitting and bedding equipment to prevent bedbugs from inhabiting and breeding. In the environmental prevention and control should focus on the places, one is in the city: to pay attention to the crowd gathered migrant workers’ dormitory, construction sites, foreign-funded enterprises’ collective dormitory; Pay attention to special units such as military barracks, hospitals, homes for the elderly, detention centres, repatriation stations and prisons; Attention to public bathrooms, saunas, foot baths, cinemas, hotels and other special industries; Concern about bedbugs in passenger ships, green train carriages, long-distance sleeper buses and waiting rooms. Second, in rural areas: attention should be paid to bedbug prevention and control in poor farmers, the homes of the elderly and lonely students, student dormitories, hospital clinics, barber shops and other places where people gather in rural areas.

• After the Second World War, bedbugs that had largely disappeared in the United States have erupted again because of fears that spraying insecticides on mattresses might be harmful to health. For this reason, the pesticide management industry in the United States is actively promoting research on insecticidal methods such as high temperature, refrigeration and steam, with a view to eradicating bedbugs.

Manual capture: knock bedstead, bedboard, kang mat, straw mattress, etc., the bedbug shock, execution, or with needles, wire picked out the gap in the bedbug, to kill.

Boiling water ironing: bedbugs are not resistant to high temperature, can use boiling water to scald all eggs and adults, bedspread bedstead, bedboard and other equipment can be moved outdoors, with boiling water bottle mouth alignment gap, slowly move ironing, must make the gap to reach high temperature, to scald bedbugs and their eggs, breeding bedbugs clothes, mosquito nets, can be soaked in boiling water.

Heating or freezing treatment: The adults, nymphs and eggs of bedbugs can be killed in only 7 minutes at 46 ℃. Put furniture such as bed in outdoor, freeze to death each insect stage bedbug; -17.8 ℃ for 2 days; -6.7 ℃ for 4-5 days.

Steam sprinkler irrigation: Various steam generators can be used to scald and kill bedbugs and eggs in the crevices by sprinkling through the orifices of the sprinkler head with steam pressure.

Solar exposure: For clothing that cannot be ironed with boiling water, expose it to intense sunlight for 1-4 hours and give it a turn so that bedbugs are killed by heat or crawling out.

Prevention of spread: In bedrooms with bedbugs, the removal (removal or sale) of luggage, furniture and other items must be strictly inspected and handled to prevent the spread of bedbugs.

• Once the population of bedbugs is established, it is difficult to get rid of them by using physical methods. At this time, chemical control methods should be used, and reasonable selection of insecticides should be paid attention to before treatment. When spraying the insecticide, we should spray the bed seam, straw mat around, account corner, table and chair and the gap of the wall, and close the door and window after spraying alcohol for 3 ~ 4 hours, and the effect is better than that of spraying the insecticide on the bedbug concealment place such as bed seam, straw mat around, account corner, table and chair.

WHO currently recommends 18 insecticides for bedbug control in 4 categories (Table 2).

	Table 2	WHO Recommended Insecticides for Bedbug Control and Their Content
Type	Name	Content (%)                     类型	Name	Content (%)
Carbamates	Chongwei	0.24	Cypermethrin ether	0.05-0.1
Organophosphorus	Chlorpyrifos	0.2-0.5	Deltamethrin	0.03
	Malathion	2.0	Beta-cyhalothrin	0.003
	Methyl pyrimidine phosphate	1.0	Permethrin	0.125
Pyrethroids	Cis-cypermethrin	0.3-0.06	Dextromethrin; dextromethrin	0.1-0.2
	Beta-cyhalothrin	0.025-0.05	Permethrin; permethrin	0.3
	Bifenthrin	0.048-0.096	Tetramethrin	0.1-0.2
	Cyfluthrin; cyfluthrin	0.04	Flufenuron; flufenuron	0.03
	Cypermethrin	0.05-0.2                   昆虫生长调节剂类	Dimethoate; dimethoate	0.09

In recent years, studies in the United States, the United Kingdom, Denmark, Australia and other countries have proved that the existing bedbugs are resistant to pyrethroids and carbamates insecticides. The results of insecticide resistance study in Australia showed that the order of insecticide resistance was organophosphorus

Because organophosphorus insecticides have unpleasant smell, can make the fabric fade and so on, and limit the place where they are used, it is suggested to add synergist when using pyrethroid insecticides to improve the insecticidal effect of organophosphorus insecticides.

In addition, the resistance of bedbugs to insecticides such as pyrethroids has prompted the research and application of other insecticides, especially insecticides with different mechanism of action from pyrethroids, such as bromofenonil and diatomite, which can effectively kill the resistant bedbugs in the United States.

            由于其作用机理独特，与其他杀虫剂作用机理不同，无交互抗性，因此， 臭虫对溴虫腈无抗药性Chlorfenapyr is a new kind of heterocyclic bionic insecticide developed by American Cyanamide Company. It is a precursor to insecticides and has no toxic effect on insects. Insects fed on or exposed to chlorfenapyr, which was converted into specific insecticidal compounds by multifunctional oxidase and acted on mitochondria in insect cells, resulting in cell death due to lack of energy. . It has been proved that it has good killing effect and no repellent effect. Now the United States is widely used, its aerosol killing effect is better than aqueous formulations, the killing effect of the day the drug reached more than 85%.

Diatomaceous earth is a pesticide commonly used to control storage pests and is registered in the United States for bedbug control. Its action mode is that diatomite particles absorb wax layer of insect epidermis, which leads to excessive water loss in insect body and finally leads to death due to dehydration. The results showed that diatomaceous earth was effective against bedbugs in all stages, especially against nymphs. Compared with traditional insecticides, diatomaceous earth has many advantages, such as good insecticidal effect, long residual life, low toxicity to mammals, long shelf life and no risk of resistance to insecticides.

The main insecticides used in our country are as follows:

Anti-bedbug medicine paper: The product is made by Military Medical Research Institute of Lanzhou Military Command with organic phosphorus as effective ingredient and synergist. The effect is reliable and the use is convenient. Usage: First, roll up the bedding on the bed, then spread the medicine paper on the bed board, and then put the bedding back to its original place. If there are bedbugs on the wall, it is best to fold the medicine paper up 10 cm where the bedboard contacts the wall, which is conducive to contact the medicine paper when the bedbugs crawl back and forth, and improve the insecticidal effect. The effective time of the paper is 260 days.

Drug brushing and spraying: According to our survey from April to June 1978, there were 1,259 single beds and 7,749 beds in the whole district

Double beds are infested with bedbugs, affecting more than 28,000 people. In the past, insecticides such as 223, DDVP and BHC, as well as sulphur fumigation and boiling water scalding were used to kill bedbugs in the army. For this reason, the commander of the military region asked us to come up with an effective anti-bedbug plan as soon as possible, so as to organize all troops in the region to unify anti-bedbug measures. Therefore, five insecticides, DDT, trichloroinsecticide, sec-butoxide, fenthion and fenthion, were selected to control bedbugs in the laboratory. The results showed that fenthion had the best insecticidal effect on bedbugs. Apply 2 grams of fenthion per square metre to a glass dish at room temperature

After 210 days, the 24-hour mortality of bedbugs exposed to 2 minutes was 100%, while the efficacy of fenitrothion was 80% and that of the other 3 insecticides was 30% ~ 60% (Table 3).

Table 3 Comparison of efficacy of 5 insecticides against bedbugs after 210 days’ storage in glass dishes

Insecticide	Dose (g/m2)	Number of tests	Number of insects tested	Average 24-hour mortality from exposure to 2 minutes (%)
Fenthion	2.	4.	80	100
Fenitrothion	2.	4.	80	80
DDT	2.	4.	80	60
7504	2.	4.	80	50
Zhong Dingwei	2.	4.	80	30
Control	–	4.	80	0

The specific method is to take 50% fenthion emulsion, add 50 times water, dilute it into 1% aqueous solution, dip it with old brush, bad toothbrush, shoe brush, etc., and brush the bed board, door, cabinet, table, chair, etc., so that all the cracks that can hide bedbugs must be coated.

In addition, the compression sprayer can also be replaced by self-made small-caliber sprayers for spraying. There was a slight odor when the medicine was applied (sprayed), but it gradually disappeared after drying in the shade. In terms of dosage, we need 500 ml of 1% fenthion solution for each single bed and 1000 ml of fenthion solution for each double bed, plus the dosage of coating camping equipment and cracks in the wall.

When eliminating bedbugs, we should pay attention to several problems. First, we should strengthen leadership, take concerted action, and organize pest control teams at all levels. Second, each unit should carefully investigate the distribution of bedbugs before medication. If a bed has bedbugs, all the beds in the room should be disposed of, and the walls, ceilings, or the whole room with bedbugs in the camp should be disposed of. Third, choose a clear day to kill insects, bedding utensils out of the dormitory, easy to hide bedbugs articles must be open exposure, indoor six sides and beds clean after applying liquid medicine, must let the liquid medicine into the crevices. Fourth, the application of liquid medicine should be inspected by a special person, every bed and all kinds of cracks should not be left out, outdoor sun-exposed clothes, books and other afternoon before withdrawal should also be inspected one by one, found bedbugs immediately crushed to death. Fifth, after one week, each company will initially check the effect of bedbug eradication, and if it is omitted or incomplete, supplementary treatment will be carried out, and after one month, the division will organize an inspection.

According to the investigation after the bedbug eradication activities, 158 companies with bedbugs could not find bedbugs (95%) in 150 companies after one administration, and a small number of bedbugs were still found in 8 companies. Most of the bedbugs were caused by low drug concentration, insufficient dosage or omission. After further supplementary treatment, all bedbugs could not be found.

Fenthion microcapsules: calculated by average 6g per single bed, diluted with appropriate amount of water and sprayed or brushed the bed board, bed frame and cave cracks in the wall, etc., pay attention to not wiping the liquid medicine on the bed board after drying, and directly spread the bedding. As fenthion microcapsule is adde with essence in that manufacturing proces, and the blocking effect of the capsule wall, the odor of the medicine is greatly reduced, and the validity period of the fenthion microcapsule can reach more than 6 months after one treatment, and the fenthion microcapsule is very suitable for indoor residual spraying.

Cypermethrin wettable powder: There were 71 soldiers’ quarters in a camp, 31 of which were found to be bedbugs, the positive rate was 43.66

%. The positive rate was 50.81% (63/124) and the bedboard bedbug index was 3.08. Cypermethrin wettable powder was mixed into 1% concentration of water and sprayed on the bed board (double-sided), the back of mat, the four walls of the room, the ground and the cabinet of the room at the dosage of 20 ~ 25ml/m ~ 2. No live worms were found after 3 days, but they were still negative after 28 days.

Bedbug control drugs and methods are commonly used in China (Table 4).

	Table 4	Bedbug control drug commonly used in China and use method thereof
Drugs and dosage forms	Concentration (%)	Dose                         施药方法	Effect
Fenthion emulsion	1.0	1000ml/m2                       喷涂	4h mortality rate 100%
DDVP emulsion	0.3	100ml/m2                        喷涂	Death rate in 4 hours was 70% ~ 100%.
Malathion emulsion	0.5	100ml/m2                        喷涂	24-hour mortality rate was over 89
Permethrin emulsion	0.5	100ml/m2                        喷涂	24-hour mortality rate 100%

• Studies on bedbug repellents There are few reports on bedbug repellents. In recent years, 32 terpenoids have been extracted from turpentine oil in cooperation with Jiangxi Agricultural University. The repellent activity of these terpenoids against bedbugs has been studied. The results show that R1 (8-hydroxyallo-carrageenan formate) and other 3 compounds have good repellent activity against bedbugs.

The treatment of 0.63 mg/cm ~ 2 was more than 72 h, and the effect was better than that of DEET. The results showed that the treatment of 0.63 mg/cm ~ 2 was more effective than DEET. The effect of DEET on bedbugs was better than that of DEET on bedbugs.

The oral LD_ (50) of R_1 to rats was more than 5000mg/kg, which was a kind of mildly toxic pesticide. It laid a good foundation for the study of repellents against bedbugs and flavonoids.

• Problems on Chemical Control of Bedbugs

Focus on insecticide resistance: The University of Kentucky reports resistance to permethrin, sometimes thousands of times higher. New York City reported 264-fold resistance to deltamethrin.

Pay attention to medication: investigate bedbug infestation beforehand; Uniformly destroy the infringing area; Clean environmental hygiene, remove dust, tear off wallpaper before treatment, so as not to affect the efficacy of medicine; Brushing was the main method of application. Seep chemicals into the crevices as much as possible: This gives bugs more exposure and is safer for humans.

• In the process of bedbug control, special object treatment should be paid attention to because of the particularity of vehicle (especially aircraft), mattress and clothing.

Vehicle handling: Bedbugs have been found in international flights and cruise ships and other means of transport abroad, but have not yet been found in inbound aircraft at home, but have been found in inbound ships, and the degree of infestation is serious, which should be paid attention to. At present, only permethrin and dextromethrin are recommended by the World Health Organization for use in aircraft, but their efficacy against bedbugs is not good. This means that the handling of aircraft depends on physical methods, including vacuum extraction and vapour handling. In the United States and the United Kingdom, heat treatment has been used to treat the whole aircraft. Because bedbugs may hide in the cracks in the aircraft, the central temperature of the aircraft is required to be controlled at 52 ~ 56 ℃ for 1 ~ 3.5 h in order to achieve the effect. Sulfuryl fluoride can also be used for fumigation of ships, trains and other public transport vehicles with serious infestation.

Mattress and Simmons treatment: Usually use exposure to mattress and Simmons treatment, but now Australia and other countries often use seamless mattress or Simmons cover treatment. This kind of bed cover is made of strong waterproof fabric,

Dense zippers with bite-resistant membranes are used to prevent bugs from biting and escaping, and to starve bugs to death (more than 12 months) after prolonged use. At present, this kind of commodity has been supplied abroad.

Disposal of clothing and bedding: The disposal of clothing and bedding, usually without the use of insecticides, involves the direct disposal of bedding, such as clothing or bedding sheets, bedding, pillows, which may be infested with bedbugs, using physical methods. The latest research shows that the adult and nymphs can be effectively killed by heating the water to 40 ℃ in the “heating mode” of household washing machine with a capacity of 3.2 kg, but the killing rate of eggs is only 70% ~ 80%. Washing with hot water at 60 ℃ can effectively kill bedbugs in all life stages. In addition, the freezing method can also be used. The study shows that it only takes 2 hours to kill all bedbugs in the freezer at-17 ℃. It takes 8 hours to put 2.5 kg loose dry clothes into the freezer from room temperature to-17 ℃, that is, it takes at least 10 hours to kill bedbugs. The more articles, the longer the time. Therefore, when handling clothing and bedding, attention should be paid to the temperature resistance and quantity of articles, and appropriate handling methods and duration should be selected.

9    Prospects

Bedbugs, as pests that have “disappeared” for many years, are re-invading mankind, which is a challenge to the control work and proves once again that it is very difficult to eradicate a pest. Bedbugs are likely to become more problematic in the future due to climate change, international travel, migration and pesticide resistance.

It is noteworthy that the problem of insecticide control is compounded by resistance to insecticides, lack of effective products and concerns about the health risks of spraying insecticides on mattresses.

Therefore, raising awareness, strengthening publicity and education is the basis of the prevention and cure work, correct diagnosis and differentiation of bedbug bites, timely detection of bedbug activity signs, research and development of effective bedbug repellents, insecticides, will be the important content of integrated prevention and cure, especially should attract the attention of PCO enterprises and other professionals.

In a word, bedbugs and other pests control is an important guarantee of spiritual and material civilization, an important measure to prevent diseases and protect health, and an important task of patriotic health movement and PCO enterprises. Therefore, bedbug and other pest control efforts:

Should be combined with patriotic health work;

Should be combined with regular health and disease prevention work; Should be integrated with the local construction and investment environment.

In this way bedbugs and other pest control work can be full of vitality for rapid and healthy development.

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