Morphometric Identification, Ecology And Olfactory Mediated Sugar Feeding Behaviour Of Culex Pipiens S.S. And Culex Torrentium Mosquitoes Of The North West Midlands Of England

Mosquito distribution data in the UK are patchy and much are too old to be useful to describe the  current  distribution.  Compounding  this,  species  that  are  particularly  challenging  to  identify result in them often being collated as complexes rather than species. Within the Culex pipiens  complex,  members  of  which  have  demonstrated  roles  as  vectors  internationally,  morphological discrimination between female Culex pipiens L. and Culex torrentium Martini cannot reliably be made without using molecular identification methods. This often results in species discrimination not being made. We also know relatively little about the sugar feeding preferences of these mosquito species, particularly in terms of males. Male mosquitoes are generally not considered as targets for control. However, recent research has demonstrated swarming  male  targeting  strategies  that  show  potential.  Therefore,  knowledge  of  these  behaviours might lead to novel approaches for control interventions or improve the effectiveness of those in development.

In this thesis, current mosquito distribution data were investigated and fieldwork conducted to add to new species presence data for North Staffordshire and environs. A recently published wing morphometric technique for the discrimination of Culex pipiens s.s. and Culex torrentium  was  tested  for  suitability  for  locally  collected  specimens,  and  subsequently  optimised and semi‐automated using a new coded workflow. Behavioural assays were conducted to assay behaviour of male Culex pipiens s.s. and Culex torrentium to olfactory cues associated with sugar feeding from flowers of various species of Apiaceae. Subsequently, a synthetic  chemical  lure,  derived  from  the  odours  of  these  flowers,  was  tested  in  the  laboratory and the field.

Fieldwork surveys collected eleven  of the thirty‐four British mosquito  species  within  the  survey, adding eight more species to the local record.

The wing morphometric approach for species discrimination, following optimisation, led to the  development  of  a  new  computerised  approach  and  workflow  that  demonstrated  84%  accurate species identification. This technique represents a viable, cost effective identification method for those without access to molecular methods, subsequently leading to better data relating to their distributions.

In behavioural assays, both Culex pipiens s.s. and Culex torrentium were shown to be attracted to Apiaceae flowers. However, there was no significant difference in preference to different flower species within the Apiaceae, nor between the two mosquito species. Following field and  laboratory  testing,  the  synthetic  lures  were  found  to  have no  significant  influence  on  behaviour or detectable catch rate increase in traps in the field.