Bed Bugs unlike Asian bugs and green bugs, do not harm crops, only humans, and some domestic animals. Their spread in recent history of modern society has had alternating phases. In recent years, it has come back into the spotlight as a health emergency. It is a very dangerous insect, not easily detectable, with a great capacity to proliferate in domestic environments. Its behavior is deceitful, as it can live for a long time without feeding. Furthermore, its bites, in most cases, are not immediately felt.
Let’s get to know bed bugs and their behavior better. Let’s see how to react in case of a bite and how to prevent infestation risks with common-sense practices. Finally, let’s explore ecologically friendly ways to eliminate them from our domestic environments.
Entomological Classification of Bed Bugs
The bed bug (Cimex lectularius) is an insect of the order Hemiptera and the family Cimicidae. It is classified as an obligate hematophagous ectoparasite of humans and other animals, mainly domestic. In simple terms, the primary target of this bug is humans. We are the main animals from which it derives nourishment through bites.
History and Spread
The history of the relationship between humans and bed bugs dates back to ancient times. The earliest writings that testify to the presence of these parasites date back to ancient Egyptian civilization over 3,500 years ago. Bed bugs were known to both the Greeks and the Romans, and their spread has continued until today. At the beginning of the last century, with the advent of heating systems, there was even an increase in infestations. The warmth of homes allowed these parasites to continue their biological cycle even in the winter months.
Starting from the 1950s, bed bug infestations experienced a significant decline. Scholars believe that this reduction was due to a dual set of factors: the general improvement of hygiene conditions and the introduction of synthetic insecticides, namely pyrethroids. However, the damage from the latter, as is known, occurs over the long term.
Starting from the 1990s, bed bugs returned to prominence and saw a progressive increase in infestations. Researchers believe that the excessive use of pyrethroid insecticides, such as the classic DDT, favored their resurgence. Bed bugs are also capable of traveling long distances, often alongside humans. Over time, the increase in international exchanges has facilitated a process of genetic reshuffling, making bed bug populations resistant to the same insecticides. In Italy, bed bugs have become primary parasites in recent years. They often cause discomfort and serious damage, including economic damage, especially in the hospitality and public transport sectors.
Identification of Bed Bugs
The adult Cimex lectularius is easily recognizable, even though the male is only 5 mm long and the female is 6 mm. The body is oval and flattened on the back, with a reddish-brown coloration. It has two lateral expansions of the pronotum and a pair of hemelytra. It has a noticeable elongated rostrum, which is held folded backward in the resting position, below the thorax. The head is small and cylindrical, with compound eyes that stand out as two dark lateral prominences. The mouthparts of bed bugs are of the piercing-sucking type. It is through this mechanism that they feed by piercing the epidermis and sucking the blood of their prey. Another characteristic, similar to other parasites such as ticks, is the ability to expand their bodies. These bugs increase their abdominal volume during their meals.
Life Cycle of Bed Bugs
Like other species of bugs, the life cycle includes three stages: egg, nymph (or instar), and adult. There are a total of five nymphal stages, and during these stages, nymphs need blood to progress to the next stage. Adults, on the other hand, feed to reproduce. However, one of the most fearsome characteristics of bed bugs is that at the adult stage, they can survive for up to a year without eating, waiting for the right opportunity. The ideal life cycle occurs when temperatures are around 30°C (86°F). The minimum and maximum temperatures that stop the cycle are 13°C (55.4°F) and 37°C (98.6°F) respectively.
Behavior of Bed Bugs
Bed bugs, as implied by their common name, prefer to take refuge in humid and fabric-rich places. Beds are the ideal environment, especially if their prey (that is, humans) rest there at night. Cracks, crevices, and small hiding places are also suitable “accommodations”. Bed bugs hide during the day as they dislike light, a characteristic known as negative phototropism. They come out of their hiding places at night to feed on blood. This parasite is attracted to the warmth and carbon dioxide emitted by its host prey. For example, if a bed bug walks on a ledge and senses the presence of prey, it can drop to the ground and directly pounce on the host’s skin. Another tendency of bed bugs is to aggregate, forming true colonies. These colonies contain fecal residues, hatched eggs, and adult individuals. This behavior aims to maintain a certain level of humidity in the nest and prevent the death from dehydration of the more susceptible juvenile forms. Another advantage of the colony is the increase in the number of matings, which is also due to the emission of aggregation pheromones.
Bites on Humans
Bed bug bites can lead to various symptoms. The most common is the appearance of erythematous or maculopapular lesions with diameters of 2-5 mm. These lesions, often very itchy, usually resolve within a week, unless secondary bacterial complications caused by scratching occur. The lesions appear a few minutes or hours after the bites, depending on individuals and the type of immune response. In some individuals, they evolve into papular urticaria, with highly itchy papules about 2-6 cm in diameter. A small hemorrhagic spot may be observed at the top of the papules. In some cases, blisters or vesicles containing clear or reddish exudate may appear a few days after the bites. Some individuals, if repeatedly bitten over a period of time, may develop a kind of “sensitization syndrome”. This involves the onset of psychological symptoms such as nervousness, irritability, and insomnia.
What to Do
The parts of the body most affected by bed bug bites are the exposed ones, particularly the face, neck, hands, and upper limbs. As much as possible, it would be advisable to cover these parts preventively. However, this is not always feasible.
To avoid scratching and complicating the symptoms with infections, immediate treatment after a bite involves rinsing the area with hot water at 50°C (122°F). This simple remedy has proven effective in relieving itching and reducing damage.
Conditions and Risks of Infestation
Bed bugs are highly mobile insects that can be introduced into a healthy environment in various ways. The most common way is through people (or objects) that come into contact with the parasite. Unknowingly, these carriers transport it to another environment, such as their own homes. An example could be bed bugs hiding and being transported in luggage.
The most at-risk environments are hotels and public transport, such as long-distance trains or buses. In hotels, beds are the main places where bed bugs find daytime refuge. They often hide along mattress seams, between wooden slats, in nets, between the bed headboard and the wall. In trains and other means of transportation, the most colonized areas are the gaps between seats or berths. A good prevention practice is to carefully inspect beds and other risk areas before staying or transiting. This caution is especially necessary if frequenting areas where hygiene and maintenance levels are low. Certainly, prevention is not simple, and it should always be the responsibility of hotel, bus, or train owners to ensure adequate hygiene standards. It is possible for an infestation to start accidentally in our homes. Let’s see how to react if this happens.
What to Do in Case of Bed Bug Infestation
Firstly, one must identify the bed bug infestation (which does not always occur in beds, as we have seen). Usually, it is sufficient to carefully monitor the possible presence of residues left by the insect. For example, tiny feces, shed skins, dead specimens. Then a decision must be made: whether to contact a professional pest control company or proceed independently. In the latter case, the nest and any infested objects, such as the mattress, must be eliminated.
An excellent method to employ is using heat, which bed bugs cannot tolerate. Using a steam machine, like this found here, simply direct the hot jet at the bed bug infestation to kill them all. These bugs are literally cooked to death, as they cannot survive temperatures above 60°C (140°F).
Steam is a very effective method as it easily reaches even difficult corners of the home. Once the infested area has been treated with steam, a regular vacuum cleaner can be used for further cleaning. The same principle is applied to clothing that may be affected by bed bugs. Washing them in hot water, raising the washing machine’s temperature above 60°C (140°F), is sufficient. To protect beds, it is advisable to always use mattress covers like these, which can be easily removed and washed at high temperatures. Other eco-friendly remedies without pesticides are traps placed in strategic points around the house. These traps are designed to attract bed bugs but prevent them from escaping. You can find a product like this here.
There are also pheromone traps available, which allow for monitoring. This type of trap, like all the remedies mentioned, avoids the use of pesticides. You can purchase it here.
- Clinical Microbiology Reviews: “Bed bugs: clinical relevance and control options” – This article delves into the clinical significance of bed bugs and discusses various control options to manage and eliminate them.
- Annual Review of Entomology: “Biology of the bed bugs (Cimicidae)” – A comprehensive review that provides insights into the biology and behavior of bed bugs, focusing on their life cycle, feeding habits, and reproduction.
- BMJ: “Bed bug infestation” – This article offers a medical perspective on bed bug infestations, discussing their health implications and offering guidance on treatment and prevention.
- Emerging Infectious Diseases: “Bed bug infestations in an urban environment” – A study that examines the increasing prevalence of bed bug infestations in urban settings and the challenges they present.
- American Entomologist: “The history of bed bug management” – This article provides a historical overview of bed bug management techniques, highlighting the evolution of control measures over time.
- Journal of Economic Entomology: “Ability of bed bug-detecting canines to locate live bed bugs and viable eggs” – Investigates the efficacy of trained canines in detecting live bed bugs and their eggs, offering a novel approach to infestation detection.
- American Entomologist: “Nonchemical control of bed bugs” – Discusses alternative methods to control bed bugs without the use of chemicals, emphasizing sustainable and environmentally-friendly approaches.
- JAMA: “Bed bugs (Cimex lectularius) and clinical consequences of their bites” – Explores the clinical manifestations associated with bed bug bites, offering guidance on treatment and prevention.
- American Entomologist: “Bed Bugs 101: the Basics of Cimex lectularius” – Provides a foundational understanding of bed bugs, discussing their biology, behavior, and significance in human environments.