1985] Smith & Valentine — Grooming behavior in cockroaches 377 
Some individuals of the more primitive species spend up to two 
minutes engaged solely in this grooming movement. 
Abdomen-Substrate Rub: Two of the smaller species (length less 
than 15 mm), Blattella germanica and Diploptera punctata, were 
observed to occasionally twist the abdomen sideways and drag the 
edge and part of the dorsal surface against the substrate. The wings 
are maintained in their normal position or raised a bit, resulting in 
only the abdomen contacting the substrate. 
Hindleg- Hindleg Rub: Individuals of only two species, S. longi- 
palpa and Schultesia lampyridiformis, place one hindleg slightly 
further under the body than normal and rub it several times from 
tibia to tarsus with rapid strokes of the tarsus of the opposite hind- 
leg. Often the movement is reversed, and the other hindleg is 
rubbed similarly. 
Wing-Hindleg Rub: A few individuals of three species, S. longi- 
palpa, Nyctibora lutzi, and L. maderae, rub the dorsal surface of the 
closed wings with the tarsus of a hindleg, while the abdomen is in its 
normal resting position beneath the wings. This movement was 
always performed while Abdomen- Hindleg Rub was in progress. 
Wing-Abdomen Rub: Several species in the families Blattellidae 
and Blaberidae (see Table 2) rub the underside of the closed wings 
vigorously and elaborately with the abdomen. There are four sepa- 
rate techniques. First, the abdomen may be rubbed from side to side 
in its normal position below the wings. Second, the abdomen may 
be flexed strongly, concave to the substrate, and the wings rubbed 
with only the central bent portion (of the abdomen). Third, the 
abdomen may be flexed strongly, convex to the substrate, and the 
tip of the abdomen rubbed in a circular or lateral motion against the 
underside of the wings. Finally the abdomen may be twisted so that 
only the lateral edge contacts the wings. When performed, these 
movements were almost always of longer duration than other 
grooming, and were usually performed between, or even during 
periods of extensive locomotion. 
Wing Flip: In Blaberidae, a period of wing flipping was some- 
times observed in conjunction with Wing-Abdomen Rub. The flip- 
ping could also be performed alone. Bouts last two to five minutes, 
with wings either flipped vertically or horizontally. 
