Bed bugs

Quick Take

• Bed bugs are older than humans, so who fed them first? Trace their ancient hosts →
• You won't feel the bite at first, and the reason is unsettling. Why bites go unnoticed →
• Bed bugs hide in far stranger places than your mattress. Find their hiding spots →
• Pesticides seem like the obvious fix, but they come with a catch. Compare treatment options →

The bed bug is an insect that feeds on blood and is most active at night. True to its name, the bed bug is most common in beds. These insects are notoriously difficult to get rid of. These parasitic insects are members of the genus Cimex. Their bites cause skin rashes, but may also cause psychological effects and allergic reactions.

History and Evolution

When it comes to evolution, it is always important to factor in what the animal ate and what was in its diet. This is because survival ability dictates adaptation and supports evolution towards being more successful at obtaining that food source. It is especially important for animals like bed bugs that require a host to feed.

Specific species of bed bugs are generally known to feed on four different types of hosts: humans, bats, water birds, and other birds. This is because they have evolved to become very adept at feeding off them. As researchers are finding, however, the history of the bed bug ancestry dates back many millions of years and predates some of their current hosts, like humans. Scientists are working on solving the puzzle of how these insects were able to make the jump between different types of hosts over their evolution.

Species, Types, and Scientific Name

Of the insects in the family Cimicidae, three species cause infestations of bed bugs:

• Cimex lectularius: Also known as the common bed bug. While these can be in the same location as the tropical bed bug, they typically are not in the same warm areas. But bed bugs can be found wherever their hosts can be found.
• Cimex hemipterus: Also known as the tropical bed bug. These are very similar in appearance to the common bed bug and have similar characteristics, and they obviously live in tropical climates.
• Leptocimex boueti: Populations of this type of bed bug are contained in South America and West Africa. This is partially due to the fact that humans actually aren’t the primary prey for this species of bed bug. Most members of Leptocimex boueti feed off of bats rather than humans, although they’re not choosy eaters.

There are 23 described species of the genus Cimex. Only four out of 90 species of bed bugs feed on humans, with the aforementioned two preferring humans. The others are bat bugs.

Appearance

Proper identification of bed bugs rules out confusion with other insects such as fleas, ticks, carpet beetles, and cockroaches. It also depends on the life stage of the bed bugs.

Adult bed bugs are five to seven millimeters long — about the size of an apple seed — and visible to the naked eye. They are brown and long with an oval-shaped, flat body unless they’ve recently fed. If it’s fed, its body is round, reddish-brown in color, and longer. As true insects, they have beaks with three segments, an antenna with four parts, wings that aren’t for flying, short, golden hairs, and a sweet, musty odor coming from glands on their undersides.

These insects have five immature or young life stages called nymphs before they become adults. Nymphs are smaller and either whitish-yellow or translucent depending on whether they’ve fed recently or not.

Bed bug eggs are pearly-white and tiny, about the size of a pinhead. If more than five days old, they have an eyespot marking.

Rather than the identification of live bed bugs, however, identification may instead mean recognizing an infestation. This is usually from early signs such as bites or spots of human blood. You may also see rusty stains from crushed bed bugs, dark spots from excrement, or pale yellow eggs and eggshells.

Early signs of bed bugs are uncomfortable, itchy nights in bed, marks on arms and shoulders, and an unpleasant odor resembling a wet towel. Symptoms of bed bug bites are skin rashes of red, itchy, flat welts in zigzag lines or clusters. The bites have a darker red spot in the middle. Some people may have allergic reactions and develop fever, severe itching, blisters, or hives. They can also cause secondary bacterial infections such as impetigo, lymphangitis, and ecthyma, as well as symptoms of psychological issues such as insomnia and anxiety.

Habitat

The habitat of these insects is worldwide, never in nature. Instead, they live in mattresses, fabrics, furniture, luggage, and pieces of wood. They hide from light and movement during the day and come out at night, so they wait in seams of furniture, curtain folds, electrical appliances, the junction of the wall and ceiling, loose wall hangings and wallpaper, and even in heads of screws. They can live singly but come together in clusters in their habitat.

Diet

The diet of bed bugs is blood. Some species prefer the blood of one mammal over another in their diet, while others absolutely need the blood of a specific mammal to survive and lay viable eggs. Those that humans deal with as pests in homes, apartment buildings, and offices feed on human blood. Their bites don’t hurt at first because they inject an anesthetic while they are feeding, which takes three to 12 minutes. Plus, they feed during the night, when it is dark and humans are asleep. Their bites most often appear on the neck, face, arms, and hands.

Prevention

To get rid of these insects more easily and quickly, noticing the early signs of bed bug infestation or symptoms of bed bug bites is important. Professionals first use visual inspection, then sniffing dogs, interceptor cups, and insect monitor cards. Ordinary people, however, need methods that don’t require a lot of money.

To get rid of them, laundering and drying with heat is one method. Vacuuming and steam treatment are others. Commercial heating services offer whole-room heat or cold treatments to kill them. You can either heat a room at 140 degrees Fahrenheit for two hours or 130 degrees Fahrenheit for three hours. Cold treatment can also work at home for small items placed in a freezer set to 0 degrees Fahrenheit. If you’re getting rid of infested furniture, make sure it’s unusable so other people won’t spread bed bugs to their own homes.

Finally, there are chemical treatments. Pesticides can be effective but need to be handled very carefully, and bed bugs can become resistant. They cannot be used on items that people come into contact with. Liquid and dry formulas should only be applied to cracks and crevices. They may include insect growth regulators as well as desiccants, which dry out these insects. They must be registered by the EPA and labeled specifically for bed bug control.

An alternative is the use of botanical oils, which are plant-based insecticides. Certain neem oil insecticides are registered for bed bug control.

As for how to prevent them in the future, a mattress encasement will protect your bed. It covers both the mattress as well as the box spring. Diatomaceous earth and pheromone traps work on everything else. It is difficult to find how to prevent bed bugs with just one method, though, so it’s best to use them together.