Laboratory and field evaluation of brown dog tick behavioral responses to potential semiochemicals

Abstract

The brown dog tick, Rhipicephalus sanguineus sensu lato (Parasitiformis: Ixodidae), is an ectoparasite of dogs that can be found worldwide. This tick poses unique difficulties in management because it can complete its entire life cycle indoors and has demonstrated acaricide resistance. The ability to monitor for tick presence and abundance is necessary for developing effective control programs. As such, an evaluation of adult brown dog tick behavioral responses to 16 potential semiochemicals was undertaken using Y-tube and straight-tube olfactometers. Both sexes of ticks were activated by nine of the 16 semiochemicals tested, including 300μg of 1-octen-3-ol, benzaldehyde, benzyl alcohol, hexanoic acid, nonanoic acid, methyl salicylate, o-nitrophenol, 2,6-dichlorophenol and salicylaldehyde. Rhipicephalus sanguineus s.l. behaviors including movement speed, direction and duration, as well as turning, were quantified following exposure to the same nine chemicals in a straight-tube olfactometer, individually at 300μg and as mixtures. Three individual chemicals, 1-octen-3-ol, hexanoic acid, and methyl salicylate induced strong responses. These three chemicals were evaluated in a semi-field setting using a modified bed bug trap but were found to provide no significant increase in attraction compared with CO alone. The results of these studies provide a foundation for future research regarding semiochemicals of R. sanguineus s.l.

Olfactory responses of Amblyomma maculatum to rumen fluid and other odourants that attract blood‐seeking arthropods

“…In the case of A. maculatum , they appeared to be either disoriented in the tube or clumped together, needing time to separate when the testing started. Because of this slowness to move into the area of the tube where a choice can be made (unlike other species and lifestages that readily move into the tube structure) (Carr et al ., ; Van Duijvendijk et al ., ) and the inability to test for vertical movement of ‘ambush’ tick species, Y‐tube olfactometers have been used as ‘tick activation screening devices’ for the preliminary screening of potential semiochemicals that may be attractive for tick species (Carnohan et al ., ). The need for this distinction was apparent in the present study because significant movement in the horizontally‐positioned Y‐tube was observed for 2‐nitrophenol and 2,6‐dichlorophenol, although activity varied considerably as a result of small differences in odourant concentration.…”

“…All studies have limitations that need to be taken into consideration. Other studies have paired odourants with CO 2 aiming to enhance the effect on a particular species (Barré et al ., ; Carnohan et al ., ). Because 2‐nitrophenol is a component of AAAP, pairing with other components (such as CO 2 ) could have made it more attractive (Barré et al ., ).…”

“…These bovine eructions would be paired with host skin odours and physical cues, such as vibrations and heat, and could trigger more aggressive host seeking in the field. Carbon dioxide acts alone or synergistically with chemical lures for blood‐feeding insects (Carr ; Carnohan et al ., ) and may have the same effect with other host‐associated volatiles.…”

“…To overcome this, Carnohan et al . () screened activating odourants using a Y‐tube olfactometer and then tested the activating compounds using a straight‐tube olfactometer that measured anemotaxis (movement toward the source of the particular odour) and chemokinesis (non‐directional responses such as turning around). Although this next level of testing was not performed in the present study, the activation effect of the semiochemicals tested on the majority of A. maculatum indicated that A. maculatum are activated by many of the same odourants reported by in other studies and have the potential for use after further testing.…”

Tools in the Investigation of Volatile Semiochemicals on Insects: From Sampling to Statistical Analysis

“…Such a device was used in order to demonstrate that an insect’s behavioral responses can be predicted after building the relationship between the chemical composition of plant volatiles and the behavioral response of insects using statistical modelling, e.g., generalized linear modeling (GLM) [5]. Additionally, the evaluation of the effect of selected potential semiochemicals (both pure and in mixture) on a group of dog ticks ( Rhipicephalus sanguineus ) was also performed [162]. In comparison to a Y-tube olfactometer, three compounds induced strong responses using a linear olfactometer, where turning and movement (speed, direction and duration) were measured after volatile compounds exposure.…”