1985] Smith & Valentine — Grooming behavior in cockroaches 381 
movements. After each flour application, as the roach was replaced 
in its culture cup, it immediately began to run in, under, and among 
the debris. This type of behavior was not observed when the roach 
was replaced without flour. After each flour trial, the greatest part 
of the flour was removed from the roach in less than one minute. 
Following the first flour trial, the roach was observed for 30 minutes 
(during which time no grooming was performed) and then removed 
and examined closely. Only minute specks of flour were visible on 
the ventral body surface. After the second flour trial, the period of 
heightened activity lasted seven minutes. As soon as the roach 
quieted it was removed and examined closely. The only remaining 
traces of flour were around the coxal bases. The roach was reexam- 
ined one-half hour later; this time, no traces of flour were found. 
The most logical conclusion is that the flour was removed from 
the roach by contact with surrounding debris. Apparently the envi- 
ronment is a significant grooming tool for this species. When the two 
individuals studied were first collected from rotten logs they 
appeared very clean and shiny with no obvious adherent particles. 
Also, the cuticle had a bright shine unlike other roaches, and on 
handling, felt distinctly waxy. This suggests a special quality which 
makes it a poor site for adherent particles. Certainly if the roach can 
be free of fine flour within an hour after returning to its natural 
habitat, other particles could be similarly removed. 
It is unlikely that the data obtained for Cryptocercus are skewed 
due to small sample size. Similar results were obtained from both 
individuals. Most important, the rapidity with which all flour was 
removed from the roach suggests that few grooming movements 
were recorded because few exist. The Cryptocercidae may in fact 
exhibit a case of evolutionary loss of grooming movements. With 
the development of a streamlined, waxy cuticle capable of shedding 
most particles, grooming would become an increasingly unnecessary 
part of the species behavior, and could easily be lost with no adverse 
effects on survival. If this is the case, it is interesting to note that the 
retention of antennal cleaning may be an indication of the impor- 
tance of this sense organ. 
Summary 
The grooming behavior of 23 species representing four families of 
Blattaria was recorded from 154 hours of observation. Specimens 
were initially observed in an undisturbed state. Several of each spe- 
