## 5 Conclusions  
In this work, we studied the chemical composition of stored sheep wool volatiles and the attractancy of wool for adult female _Ae. aegypti_ mosquitoes. The wool extracts were obtained by hydrodistillation and the various HS extraction methods. A total of 52 compounds were still present in stored wool detected by GC-MS and GC-FID/GC-MS methods. Seven compounds were not reported previously in the sheep products to the best of our knowledge. These compounds were collected by various extraction methods,and were detected with one and/or another spectrometry techniques, so the methods complemented each other. The hydrodistillate mainly contained thialdine detected by both spectrometry techniques. The main components of DHS volatile extract identified by GC-MS were alkanes, and, by GC-FID/GC-MS were alcohols. The main components of HS-SPME extracts identified by GC-FID/GC-MS in PDMS/DVB, and C/PDMS collections were alcohols and aldehydes, while ion was the main component when PDMS was used as absorbent. Many of the detected compounds were previously reported as having some level of attractancy against mosquitoes. The sheep wool hydrodistillate and its main component thialdine did not show any significant attractant activity in the glass tube tests. Semi-field bioassays in the outdoor large screened cages equipped with the CDC traps and Vortex apparatus revealed the bait with vibrated sheep wool was a significantly better attractant (RA \(\sim\)0.70) than the bait with no wool and no vibration. In baits with vibrated sheep wool, attraction to mosquitoes could be influenced by combination of olfactory, and visual cues (also, sound from vibrated Vortex might influence mosquito behavior). Of these, olfactory signals seem to be the most important. We assume that under dynamic conditions stored sheep wool more intensively releases volatiles while the emission is limited when wool is not moving and this approach could be an option for increasing the efficacy of mosquito capture in bait systems. In the future, on the basis of identified potential attractants from the raw sheep wool volatiles, various blends could be tested for attractancy against mosquitoes, in order to find new active volatile combinations that increase mosquito capture in the traps. Research on raw sheep wool could be extended to test sheep wool baits with CO\({}_{2}\), and light; and experiments could be conducted with other natural materials. Sheep wool is an easily available, affordable, and environmentally friendly product that should make this material attractive for use in mosquito management and surveillance.  
Conceptualization, M.T., N.T. and D.L.K.; methodology, M.T., N.T. and D.L.K.; investigation, M.T., N.T., D.L.K., B.D. and L.Y.; resources, U.R.B., K.J.L. and J.R.B.; data analysis, M.T.; writing--original draft preparation, M.T. and N.T.; writing--review and editing, U.R.B., K.J.L., D.L.K., J.R.B. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Deployed War-Fighter Protection Research Program and funded by the United States Department of Defense through the Armed Forces Pest Management Board [Agreement 60-0208-4-001 and under USDA Specific Cooperative Agreements 58-0208-0-068 and 58-0208-5-001].  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
We thank [PERSON] (USDA-Agricultural Research Service-Center for Medical, Agricultural, and Veterinary Entomology) for support with HS collection technique; Center for NMR Spectroscopy, University of Florida, Gainesville, FL, USA.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.