2005 Volume 20 Issue 1 Pages 15-18
Feces of domiciliary cockroaches often contaminate food or medicine packages. The presence of feces in foraging places is an evidence of a cockroach infestation. The shape and other characteristics of feces are different among species. When they are fed on the mouse chow and adequate amount of water, Blattella germanica deposits feces of approximately 0.70mm long in the male and 0.95mm in the female, the size of which is the smallest among different species, while the largest size of feces is deposited in Periplaneta americana , the size of which is approximately 3.93mm in male and 4.35mm in female. The size of feces of other species is between the above two. On the other hand, when they were fed on an agar-gelatin in order to control water supply, the size of feces decreased in all species. The feces of P. fuliginosa showed high viscosity and have a tendency to contaminate the surface of packages and P. americana and B. germanica produced feces with a considerable viscosity. However, the feces of P. japonica and P. brunnea were always so solid that the possibility of their package contamination appears to be low.
