Mosquitoes species complex

Species complexes are groups of closely related species which are almost morphologically indistinguishable from each others by ordinary taxonomic methods. They may also differ with respect to ecological, behavioral characteristics ( breeding, feeding, bitting ) and vectorial capacity and difference at chromosome level.Members of closely related although reproductively isolated,cross mating may produce sterile and/or substandard offsprings (4-5). The significance of species complex is some of the species are vector of disease, while other are not.

Species complexes are of two types. The "allopatric" complex ; only one form in the local area but occures in different forms in adjacent area). The "sympatric" complex ; more than one forms within the local area, consists of "sibling species" and "polymorphic species". Sibling species have minimal morphlogical differennces, productively isolated and ecologically distinct . Polymorphic species consist of two or more rather distinct looking forms occur simultaneously in the same area.

Many of the major vectors of malaria belong to species complex, for example, An. balabacensis (dirus) complex (6-8), An. philippinensis-nivepes complex (9), and An. maculatus complex (10-11) in Southeast Asia, An. gambiae complex (12) and An. albitarsis comlex (13) in Africa.

The Anopheles maculatus species complex in Thailand.

Anopheles ( Cellia ) maculatus sensu lato is an important vector of malaria in certain areas of its distribution such as a part of Island of Sumatra, Peninsular Malaysia, and Southern Thailand. The studies based on polytene chromosome rearrangement revealed that An.maculatus from Thailand consist of 7 forms (A, B, C, E, F, G, H) (13),