Multisensory control of escape in the cockroach Penplaneta americana

Abstract

• 1. Interactions of cockroaches with 4 different predator species were recorded by videography. Some predators, especially spiders, struck from relatively short distances and usually contacted a cockroach prior to initiation of escape (Table 1, Fig. 3). This touch frequently occurred on an antenna. Cockroaches turned away from the side on which an antenna was touched.

• 2. We then measured the success of escape from predators for cockroaches with either cerci or antennae ablated. Only antennal removal caused a significant decrease in the success of escape from spiders (Fig. 5).

• 3. With controlled stimuli, cockroaches responded reliably to abrupt touch of antennae, legs or body (Fig. 6). Responses resembled wind-elicited escape: they consisted of a short latency turn (away from the stimulus) followed by running (Figs. 7, 8). However, lesions show that touchevoked escape does not depend on the giant interneuron system (Table 2).

• 4. Following section of one cervical connective, cockroaches continued to respond to touching either antenna, but often turned inappropriately toward, rather than away from, stimuli applied to the antenna contralateral to the severed connective (Table 3, Fig. 10).

• 5. For certain types of predators touch may be a primary cue by which cockroaches detect predatory attack. Descending somatosensory pathways for escape are distinct from the GI system.