|Description:||This digitally-colorized scanning electron microscopic (SEM) image revealed some of the ultrastructural morphology displayed on the head region of a bedbug, Cimex lectularius. Of interest is one of the insect’s compound eyes.|
The compound eye is given this name due to the fact that the single large eye is really made up of many repeating units known as "ommatidia”. Each ommatidium is composed of separate units made up of a photoreceptor cell, support cell, and pigment cells. Though each of these visual mechanisms functions as a separate organ, together they provide the organism with a "compound” picture of its environment. Due to what is referred to as the "flicker effect”, the compound eye is made very sensitive to movement, with each ommatidium turning on and off, as objects pass across its field of view. The bilateral anatomical placement of the insect's eyes provides the organism with a very wide range of visual sensitivity.
Bedbugs are not vectors in nature of any known human disease. Although some disease organisms have been recovered from bedbugs under laboratory conditions, none have been shown to be transmitted by bedbugs outside of the laboratory.
The common bedbug, C. lectularius is a wingless, red-brown, blood-sucking insect that grows up to 7mm in length, and has a lifespan from 4 months up to 1 year. Bedbugs hide in cracks and crevices in beds, wooden furniture, floors, and walls during the daytime and emerge at night to feed on their preferred host, humans.
C. lectularius injects saliva into the blood stream of their host to thin the blood, and to prevent coagulation. It is this saliva that causes the intense itching and welts. The delay in the onset of itching gives the feeding bedbug time to escape into cracks and crevices. In some cases, the itchy bites can develop into painful welts that last several days.