ANTENNAL GROOMING AND MOVEMENT BEHAVIOUR IN THE GERMAN COCKROACH, BLATTELLA GERMANICA (L.)

Abstract:
The antennal grooming behavior in Blattella germanica (L.), involves the coordinated use of the foreleg tibia and tarsus, and the mouthparts. The foreleg opposite the antenna is used to bend the flagellum to the mouthparts, after which it is pulled through the labium and maxillum by the resilience of the bend in the flagellum. Antennal grooming behavior is a sequence of five distinct events which define a grooming episode. Under normal conditions each antenna is groomed in 3-6 sec, and both antennae may or may not be groomed in successive episodes. When exposed to unfamiliar environments laboratory (VPI) and field (RHA) strain cockroaches display a distinct sequence of movement and antennal grooming rates (groomings / min) during the initial 5 min. Antennal grooming in both strains increases from the resting rate (0.23 = VPl, 0.95 = RHA) to the investigative rate (1.10 and 1.80 grooming per min, respectively) after 3 min exposure, but shortly returns to the resting rate. Response to a chemical and nonchemical stimulus rapidly increases the antennal grooming from the resting rate to the irritation rate, at which time the antennae collapse to the substrate.