Masters Project (Starting 2004 - Katrin Jahreiss): "Methods for the investigation of floral odors as attractants for mosqitoes" (In cooperation with Martin Geier, BioGents, Regensburg)

Feeding on sugars and other plant substances was thought to be characteristic mainly of male mosquitoes (see Mattingly 1971). Nowadays, feeding on floral nectar is now known to occur frequently, also among females (Foster 1995, Gary & Foster 2001). It has been shown in field (Nielsen & Greve 1950, Hocking 1953, Haeger 1955) and under laboratory conditions (Gillett et al. 1962) that male and female mosquitoes feed on sugar. Healy & Jepson (1988) and Foster & Hancock (1994) found that floral odours play an important role in the attraction of mosquitoes to flowers. Moreover, they demonstrated that odours alone without optical signals could trigger mosquito landings.

In 2004 Katrin Jahreiss started her project to identify floral scent compounds that are responsible for the attraction of mosquitoes (GC-MS, GC-EAD, single cell recording, wind tunnel bio tests).

Male mosquito on S. otites	Female mosquito on S. otites

Mosquitoes searching for nectar	During day other (syrphid) flies can be observed as flower visitors.

Objectives

(1) The efficiency of floral odour blends enriched with attractive floral scent compounds will be tested for the attraction of mosquitoes in field-bioassays

(2) Investigation of pollen loads on mosquitoes will give information on local plant species that are used by mosquitoes as carbohydrate sources. These plants will be screened for floral odours that might be attractive for mosquitoes.

Cooperations

This project will be accomplished in close cooperation with the company BioGents. Their trap system for mosquito monitoring will be used in field bioassays with newly developed scent blends. Further, the trap system will be used for the monitoring of the influence of vegetation and planted greenery in towns on mosquito populations.

This project is supported by the DFG (Graduate College 678 - University of Bayreuth)

References

Brantjes, N.B.M. & Leemans, J.A.A.M. 1976. Silene otites (Caryophyllaceae) pollinated by nocturnal Lepidoptera and mosquitoes. Acta Bot. Neerl. 25: 281-295.

Foster, W.A. 1995. Mosquito sugar feeding and reproductive energetics. Ann. Rev. Entomol. 40: 443-474. 

Foster, W.A., & Hancock, R.G. 1994. Nectar-related olfactory and visual attractants for mosquitoes. J. Am. Mosq. Control. Assoc. 10: 288-296.

Gary, R.E. jr., & Foster, W.A. 2001. Effects of available sugar on the reproductive fitness and vectorial capacity of the Malaria Vector Anopheles gambiae (Diptera: Culicidae). J. Med. Entomol. 38: 22-28. 

Gillett, J.D., Haddow A.J., Corbet P.S. 1962. The sugar-feeding cycle in a cage-population of mosquitoes. Entomologia exp. appl. 5: 223-232. 

Haeger, J.S. 1955. The non-blood feeding habits of Aedes taeniorbynchus (Diptera: Culicidae) on Sanibel Island, Florida. Mosquito News. 15: 21-26.

Healy, T.P. & Jepson, P.C. 1988. The location of floral nectar sources by mosquitoes: the long-range response of Anopheles arabiensis Patton (Diptera: Culicidae) to Achillea millefolium flowers and isolated floral odour. Bull. ent. Res. 78: 651-657. 

Hocking, B. 1953. The intrinsic range and speed of flight of insects. Trans. R. ent. Sot. Lond., 104, 222-345. 

Mattingly, P.F. 1971. Ecological aspects of mosquito evolution. Parassitologia. 13: 31-65. 

Nielsen, E.T. & Greve H. 1950. Studies on the swarming habits of mosquitoes and other Nematocera. Bull. ent. Rex. 41: 227-258.

_{Andreas Jürgens}