Morphological variation in salivary glands of colonized and wild populations of Anopheles darlingi from the Peruvian Amazon

Anopheles female mosquitoes’ salivary glands play an important role in malaria transmission. These organs host Plasmodium sporozoites, which are the infectious parasite stages instilled through mosquito bites to humans. Previous analysis of wild An. darlingi salivary gland pairs described atypical morphologies with salivary glands occasionally presenting more than three lobes, yet more detail documentation of atypical salivary glands and functionality is lacking. In this study, we examined the external morphology of salivary glands in wild and colonized An. darlingi to determine whether atypical organs are found in both types of mosquito populations, by digitally documenting atypical morphologies. Salivary glands of 422 An. darlingi females, 197 wild and 225 colonized specimens, were dissected. We found nine atypical salivary gland pairs with four atypical morphologies recorded in wild mosquitoes representing 11.2% (22/197) of specimens dissected, and seven atypical morphologies in colonized mosquitoes representing 13.8 % (31/225) of specimens dissected. These preliminary results suggest that variation in salivary gland morphology is similar between wild and colonized An. darlingi.  Future studies will explore whether these atypical morphologies are relevant to traits associated with malaria transmission, further exploring parasite-vector-host interactions to support malaria drug and vaccine research.
 Key words: Salivary glands, morphology, Anopheles darlingi, Peruvian Amazon.