Abstract:
Many species of Anopheles mosquitoes (Diptera: Culicidae) are now recognized
as species complexes whose members are often indistinguishable morphologically but
identifiable based on ecological, genetic, or behavioural data. Because the members of
species complexes often differ in their vector potential, accurate identification of vector
species is essential for successful mosquito control. To investigate the cryptic species
status of Anopheles mosquitoes in Canada, specimens were collected from across the
country and examined using morphological, molecular, and ecological data.
Six of the seven traditionally recognised species from Canada were collected from
locations in British Columbia, Quebec, Newfoundland and Labrador, and throughout
Ontario, including Anopheles barberi, An. earlei, An. freeborni, An. punctipennis, An.
quadrimaculatus s.l., and An. walkeri. Variation in polymorphic traits within An. earlei,
An. punctipennis, and An. quadrimaculatus s.l. were quantified and egg morphology
examined using scanning electron microscopy. Morphological identification of adult and
larval specimens suggested that two described cryptic species, An. perplexens and An.
smaragdinus, were present in Canada.
DNA sequence data were analysed for evidence of cryptic species using three
molecular markers: COl, ITS2, and ITS!. Intraspecific COl variation was very low in
most species «1 %), except for An. punctipennis with 2% sequence divergence between
those from British Columbia (BC) and Ontario (ON), and An. walkeri with 7% sequence
divergence between populations from Manitoulin Island (NO) and Long Point Provincial
Park (LP). Similar patterns were also seen using ITS2 and ITS 1. Therefore, molecular data revealed the presence of two putative cryptic species within two species examined
(i.e., An. walkeri and An. punctipennis), corresponding to collection location (i.e., NO vs.
LP and BC vs. ON, respectively). Surprisingly, there was no molecular support for the
presence of either An. perplexens or An. smaragdinus in Canada despite the
morphological assessments.
Ecological data from all collection sites were recorded and are available in an
online database designed to manage all collection and identification data. Current
bionomic information, including regional abundance, larval habitat, and species
associations, was determined for each species. This multidisciplinary study of Anopheles
mosquitoes is the first detailed investigation of these potential disease vectors in Canada
and demonstrates the importance of an integrated approach to anopheline systematics that
includes molecular data.
