1985] Smith & Valentine — Grooming behavior in cockroaches 379 
appearance of the roach’s body the next day clearly indicated that 
leg cleaning and abdomen, cercus, and basal antenna rubbing had 
been performed. Using a red filter, two additional movements were 
observed: Foreleg and Pronotum Clean. Unfortunately, the single 
specimen died before a complete repertory was observed. 
Ordinal Patterns. 
The most striking characteristic of grooming in the order Blatta- 
ria is the remarkable stereotypy of the movements. In grooming a 
particular structure, one method usually suffices for all species. 
Despite varied habitats as living in loose sand, or flowers, or in bird 
nests (Roth, 1973), roaches groom legs, palpi, head, and abdomen in 
the same way. 
Stereotyped methods and modes of grooming may be explained 
by considering the generalized anatomy of the group and the natural 
habitats of the species. The cockroaches are a very ancient order 
little changed in morphology since their time of dominance in the 
Carboniferous Period. Fossil and contemporary roaches are ana- 
tomically very similar. Since extant species are not substantially 
different in external morphology from either ancestral species or 
each other, there has been little or no pressure to evolve new groom- 
ing patterns to deal with specialized anatomical constraints. Also, 
roaches are cosmopolitan in their distribution and superficially 
diverse in their habitats. Unlike interstitial Diplura (Valentine and 
Glorioso, 1979), none of these habitats places undue physical restric- 
tions on the animals. Roach habitats are cryptic, but none confines 
a species exclusively to cramped quarters, therefore there is no evi- 
dence for selection favoring open-ended and complex repertories 
like those of Diplura. 
Familial Patterns. 
Discussion of familial trends in grooming behavior lends greatest 
insight into roach phylogenetic relationships. Some differences exist 
at other taxomonic levels (Bobula, MS), but these are either incon- 
sistent or based on small sample sizes. 
The grooming movement most useful in interpreting blattarian 
phylogeny is Antenna Clean. Other movements form less clear pat- 
terns among groups and hence offer no aid in clarifying general 
phylogenetic relationships. 
Based on trends in Antenna Clean, consistent familial differences 
exist between the families with generalized reproductive behaviors 
