Yee, D. A. | bioRxiv Science

bioRxiv2019

Linking nutrient stoichiometry to Zika virus transmission in a mosquito

Food quality and quantity serve as the basis for cycling of key chemical elements in trophic interactions, yet the role of nutrient stoichiometry in shaping host-parasite interactions is under appreciated. Most of the emergent mosquito-borne viruses affecting human health are transmitted by mosquitoes that inhabit container systems during their immature stages, where allochthonous input of detritus serves as the basal nutrients. Quantity and type of detritus (animal and plant) were manipulated in microcosms containing newly hatched Aedes aegypti mosquito larvae. Adult mosquitoes derived from these microcosms were allowed to ingest Zika virus infected blood and then tested for disseminated infection, transmission, and total nutrients (percent carbon, percent nitrogen, ratio of carbon to nitrogen). Treatments lacking high quality animal (insect) detritus significantly delayed development. Survivorship to adulthood was closely associated with the amount of insect detritus present. Insect detritus was positively correlated with percent nitrogen, which affected Zika virus infection. Disseminated infection and transmission decreased with increasing insect detritus and percent nitrogen. We provide the first definitive evidence linking nutrient stoichiometry to arbovirus infection and transmission in a mosquito using a model system of invasive Ae. aegypti and emergent Zika virus.

ecology↗

bioRxiv2018

A barcoding approach to phylogenetic classification of Aedini mosquitoes (Aedes, Ochlerotatus)

Traditionally, entomologists have used morphological characteristics for mosquito taxonomy and systematics. However, this approach does not take into consideration the genetic relatedness of species. In 2000, the Aedes genus of mosquitoes in the tribe Aedini was split into two genera (Aedes and Ochlerotatus), thereby elevating Ochlerotatus from subgenus to genus rank, strictly based on morphology of adults. Herein, we use the genetic barcoding marker COI to generate a phylogeny of 65 species of Aedes, Ochlerotatus, and Anopheles outgroup from almost 900 sequences downloaded from BOLD systems. Our results reveal evidence of non-random, but polyphyletic clustering of Aedes and Ochlerotatus species, with a monophyletic outgroup. We do find support for the validity of Ochlerotatus as an evolutionary unit, although we find insufficient evidence to support its retention as a genus. We suggest that mosquito phylogenetic analyses incorporate a greater number of genetic markers to help clarify our understanding of Aedini species classifications, but caution that recent assessments based solely on morphology may be insufficient.

evolutionary biology↗