Evidence for the Sensory Receptor(s) of the Mounting Sex Pheromone in Two Species of Ixodid Ticks, <i>Dermacentor variabilis</i> (Say) and <i>Dermacentor andersoni</i> Stiles

<p>The foreleg claw sensilla were determined to be the receptors of the female contact sex pheromone, MSP (mounting sex pheromone), in <em>D. variabilis</em>, <em>D. andersoni</em> and<em> A. americanum</em> male ticks. In all three tick species, the claw sensilla consists of six anteriorly-directed setae arranged in three symmetrical pairs, two each on the opposite sides of the apotele of the claw and one on the ventral side. Behavioral bioassays and morphological study of these setae revealed that only the dorsal and middle (= lateral) pairs of claw sensilla are mechanogustatory, while the ventral pair are strictly mechanoreceptors. The dorsal and middle sensory setae exhibit a single pore-like structure located at their tip, a feature characteristic of gustatory or mechanogustatory sensilla similar to those found on the palps that are believed to function as pheromone receptors. Similarities in structure and function with contact chemosensilla of insects also are discussed.</p> <p>In all three tick species, male mounting and post-mounting behaviors were suppressed only when the dorsal and middle pairs of claw sensilla were ablated or covered with gelatin; normal behavior was restored when the gelatin was removed. Dose-response bioassays were conducted with<em> D. variabilis</em> males to authenticate the results of the gelatin tests. The results of these bioassays demonstrated that the gelatin did not permit molecular penetration of the pheromone. Results of transfer of stimulus bioassays, in which only the MSP, cholesteryl oleate, was applied to inanimate objects (beads), demonstrated that male ticks responded only to the pheromone and mating behavior could be regulated by covering or uncovering the foreleg claw sensilla with gelatin. The significance of these findings for an understanding of mating behavior in ixodid ticks is discussed.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

1992

Author dc:creator

• Phillips, James Stephen

Contributors dc:contributor

• Daniel E. Sonenshine
• Keith A. Carson
• Norman J. Fashing

• Sensory receptors
• Sex pheromone
• Ticks
• Ecology and Evolutionary Biology
• Entomology

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Repository record dc:identifier

https://digitalcommons.odu.edu/biology_etds/99

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:biology_etds-1099