How to obtain a bloodmeal without being eaten by a host: the case of poultry red mite, <i>Dermanyssus gallinae</i>

Abstract

Abstract. The behavioural responses of the poultry red mite, Dermanyssus gallinae , to three host‐related stimuli, vibration, heat and CO 2 , are studied in light and dark. Although D. gallinae usually feeds on host‐blood at night, it can also be day active after a few days of starvation. However, the immediate response of the mites to CO 2 in daylight is to freeze and remain motionless. Even with simultaneous presentation of an activating stimulus (heat), the mites freeze in response to CO 2 . In the case of subsequent vibrations, they start moving but only for the duration of the vibrations. After 2 min, the freezing response disappears and the level of activity is significantly higher than for mites stimulated with vibrations alone. The freezing response is interpreted as a defence against being eaten by the host that apparently is close enough to breathe on the mites. At low‐light intensities, where the birds are unable to see the mites, there is no freezing response, but only a synergistic effect of heat and vibration on the level of activity. The frequency of vibration most efficient in eliciting movement during the freezing response is found at 2 kHz with a threshold value of 35 µm s −1 peak‐peak, suggesting that D. gallinae is more sensitive to substrate‐borne vibrations than some insects (e.g. honeybees) known to use vibrations for intraspecific communication.