Common vs. Tropical
There are two main types of bed bugs, the common bed bug and the tropical bed bug.
The common bed bug is much more prevalent with the tropical bed bug only rarely found and unless transported, is only found in very warm climates in the United States.
The common bed bug is found globally while the tropical bed bug is found mostly in equatorial Africa and other very warm climates including parts of the continent of Australia and even Florida.
The Common Bed Bug
The common bed bug (Cimex lectularius Linnaeus) is the most widely known.
The common bed bug has plagued humans for all of history. This little pest has been controlled by burning sulphur in thousands of years ago. The common bed bug was such a problem in Europe that in England, the royalty had appointed bed bug control experts. The common bed bug feeds on human blood preferably, but will feed on other types of blood as well if necessary. The western world enjoyed a few decades, from the 1960s to late 1990s, where bed bugs were a rarity. That has changed in recent years with an explosion of bed bug infestations, especially after 2005.
Many insects resemble bed bugs and sometimes there is confusion and even experienced people will misidentify all similarly looking insects as bed bugs. Even if bed bugs are not the primary pest, similar pests may bite. Also, these other insects may be mistaken for bed bugs, which prefer human blood.
Common bed bugs are generally flat and oval if not fed recently and adults are about 3/16” long. The young, or nymphs, are smaller and early stages are nearly impossible to see. Read more about identifying bed bugs.
Eggs are small and are glued to surfaces making them difficult to find. Eggs are about 1/32” long. Read more about the life cycle.
The Tropical Bed Bug
The most common species of tropical bed bugs is (Cimex hemipterus), normally found in the tropics.
There are also more regional species of tropical bed bugs but these are less important globally. The biology and habits of the common and the tropical bed bug are similar and the tropical bed bug can be found in areas other than tropics.
It takes a trained eye to be able to determine positively if a specimen is a tropical bed bug. Since tropical bed bugs are so rare, it is good bet that specimens of bed bugs found are common bed bugs; however, positive identification is important. Tropical bed bugs have similar biology to the common bed bug so they will wreak havoc on homes just as readily as common bed bugs.
From an identification point, bed bugs have rounded prothorax portions near the eye where the tropical bed bug has squared off and deeper prothorax near the eye.