The Air-puff Evoked Escape Behavior of the Cricket Gryllus bimaculatus and its Compensational Recovery after Cercal Ablations

Abstract

The air-puff evoked escape behavior of the cricket, Gryllus bimaculatus, was investigated. Crickets almost always escaped away from the stimulus source. In an optimal condition, the mean escape direction was 162° opposite to the stimulus source. Stronger (higher velocity) air-puff elicited an escape in larger number of crickets. However, the escape direction became incorrect when the stimulus was too strong.Crickets with bilateral cercal ablation did not show any escape to an air-puff, while unilaterally ablated ones did respond to the same stimulus with an escape. However, the response rate of animals with unilateral cercal ablation was lower than that in intact animals. Although the mean escape direction of the crickets with unilateral cercal ablation was still opposite to the stimulus source, the direction was not so accurate as in intact animals.About 6 days after the unilateral cercal ablation, the response rate showed a statistically significant compensational recovery. On the other hand, 14 days were necessary for the recovery of the escape direction. Information which regulating the response rate and the behavioral orientation is likely being processed in different neural pathways.

Danger detection and escape behaviour in wood crickets

“…These velocities appear to be too high compared to that generated by an approaching predator Magal et al, 2006). Moreover, a stimulation of 90 cm/s induces a low response in the crickets as only 1.3% and 10% of the crickets reacted respectively (Kanou et al, 1999(Kanou et al, , 2006, whereas in our experiments 43% of the adult crickets (and 80% of J1) responded to a stimulation of 25 cm/ s.…”

“…It has been reported that Troglophilus neglectus crickets use a different sequence of movements to escape: they jump backward, away from the stimulus (Schrader, 2000), which could constitute a better strategy to quickly create distance between the cricket and objects approaching from any direction. The ability to detect approaching objects was higher in our experiments than that observed in Gryllus bimaculatus (Kanou et al, 1999), or in Gryllodes sigillatus (Kanou et al, 2006). Our study was conducted using a piston approaching at 25 cm/s, a speed that seems to evoke the highest escape response of N. sylvestris (Dangles et al, 2006b).…”

“…Most previous studies on the escape behaviour of crickets have been conducted by stimulating the crickets with air puffs (Kanou et al, 1999(Kanou et al, , 2006Schrader, 2000;Tauber and Camhi, 1995). This type of stimulation, although easily controllable, neither distinguishes the different steps involved in escaping, nor evaluates the relative contribution of cerci in attack detection.…”

“…In other species, the air-speed employed to stimulate escape with air-puffs was much higher. For instance, a stimulation velocity of 90 and 300 cm/s were used in studies using G. bimaculatus and in G. sigillatus (Kanou et al, 1999(Kanou et al, , 2006. These velocities appear to be too high compared to that generated by an approaching predator Magal et al, 2006).…”

“…Studies on these insects focused on the neural basis of wind-detection (Bacon and Murphey, 1984;Jacobs and Miller, 1985;Jacobs andTheunissen, 1996, 2000;Jacobs et al, 1986Jacobs et al, , 2008Miller and Jacobs, 1984;Miller et al, 1991;Murphey, 1981;Paydar et al, 1999;Yono and Shimozawa, 2008), on the escape behaviour (Gras and Hö rner, 1992;Kanou et al, 1999Kanou et al, , 2006Tauber and Camhi, 1995;Schrader, 2000), and on the plasticity and recovery after cercal ablation (Kanou and Kondoh, 2004;Kanou et al, 1999Kanou et al, , 2001Kanou et al, , 2002. To stimulate the cerci, most studies employed air-puffs directed towards them.…”