- University of New Brunswick
Summary
In this study, potential cues for detachment of parasitic larval Arrenurus danbyensis Mullen mites from Coquillettidia perturbans (Walker) mosquitoes were investigated. Contact with water did not induce a dramatic rate of dissociation. Crushing the host's abdomen was not as effective as crushing the head or thorax; although general body trauma has an effect, it is not sufficient to explain these results. Crushing the host's head following application of a ligature slowed the rate of mite detachment. We infer that haemolymph-borne cues, possibly hormones, are released by crushing the head or thorax of the host and induce rapid mite detachment. External application of Ringers solution or body fluids from mosquitoes significantly increased rate of mite detachment. It is possible that two separate mechanisms stimulate detachment of mites: external haemolymph reception signifying damage to the host and internal reception of haemolymph-borne cues associated with oviposition behavior.
Methodology
Experiments were conducted at Queen's University Biological Station (approximately 50 km north of Kingston, Ontario). Mosquitoes and their associated mites were collected between mid-June and mid-July 1987, corresponding to the period of emergence for C. perturbans recorded by Mullen (1974) and Smith and McIver (1984). Mosquitoes were collected in the evening from the screens of lighted buildings and from people as the insects attempted to bloodfeed. Mosquitoes were trapped alive in plastic snap-top vials.