1.A method for distinguishing the important malaria vectors Anopheles dirus and An. cracens (Diptera: Culicidae) based on antennal sensilla of adult females
Taai, K. ; Harbach, R.E. ; Somboon, P. ; Sriwichai, P. ; Aupalee, K. ; Srisuka, W. ; Yasanga, T. ; Phuackchantuck, R. ; Jatuwattana, W. ; Pusawang, K. ; Saeung, A.
Tropical Biomedicine 2019;36(4):926-937
Some species of the Anopheles dirus species complex are considered to be highly
competent malaria vectors in Southeast Asia. Anopheles dirus is the primary vector of
Plasmodium falciparum and P. vivax while An. cracens is the main vector of P. knowlesi.
However, these two species are difficult to distinguish and identify based on morphological
characters. Hence, the aim of this study was to investigate the potential use of antennal
sensilla to distinguish them. Large sensilla coeloconica borne on the antennae of adult females
were counted under a compound light microscope and the different types of antennal sensilla
were examined in a scanning electron microscope. The antennae of both species bear five
types of sensilla: ampullacea, basiconica, chaetica, coeloconica and trichodea. Observations
revealed that the mean numbers of large sensilla coeloconica on antennal flagellomeres 2, 3,
7, 10 and 12 on both antennae of both species were significantly different. This study is the
first to describe the types of antennal sensilla and to discover the usefulness of the large
coeloconic sensilla for distinguishing the two species. The discovery provides a simple,
reliable and inexpensive method for distinguishing them.