Quantification of fecal spot production as a measure of environmental contamination based on common bed bug (Hemiptera: Cimicidae: Cimex lectularius L.) population size

The presence of fecal spots has often been used to verify the existence of a bed bug (Cimex lectularius) infestation. However, no research has been conducted to determine how much fecal material that a bed bug population produces over time. In this study, the number of fecal spots that each nymphal life stage was capable of producing after a bloodmeal was quantified. Adult fecal spots were also quantified to determine if there was consistent production between feedings. During this study, it was discovered that bed bugs produced visible fecal spots and clear spots that were only visible under ultraviolet light. Therefore, three types of fecal spots were quantified: dark feces, light feces, and clear spots. Clear spots were produced in greater amounts (38.5–55.5%) than either dark spots (27.3–40.7%) or light spots (17.3–21.9%). For example, 5th instar bed bugs were thought to produce an average of 21 spots (dark and light) after a single bloodmeal. However, using the ultraviolet light, it was found that the 5th instars actually produced an average of 44.7 spots. Using the total fecal spot data collected during this study, researchers could project contamination potential for an infestation starting with a single gravid female over 30, 60, and 90 days. In addition, the amount of area covered by these spots was projected to be over 12 m² in just 3 months, which could greatly reduce the environmental and aesthetic quality of a home.