Technical Limitations Associated With Molecular Barcoding of Arthropod Bloodmeals Taken From North American Deer Species.

Accurate species-level identification of the source of arthropod bloodmeals is important for deciphering blood feeding patterns of field-collected specimens. Cytochrome c oxidase I (COI) mitochondrial gene sequencing has been used for this purpose; however, species resolution can be difficult to obtain from certain vertebrate genera, including Odocoileus. Sanger sequencing of mitochondrial genes was employed to identify the bloodmeal source of wild-caught mosquitoes trapped in Greeley, Colorado. Initial sequencing of the COI gene of mitochondrial DNA in bloodmeals was inadequate for species-level resolution of bloodmeals from deer in the genus Odocoileus, with current databases returning low fidelity matches to multiple genera. The use of the hypervariable D loop of the control region provided species-level identification of white-tailed deer (Order: Artiodactyla, Family: Cervidae, Odocoileus virginianus); however, taxonomic identification was successful only to genus for mule (O. hemionus hemionus) and black-tailed deer (O. hemionus columbianus). We advocate the use of multiple loci for bloodmeal analysis and the buildout of available databases to include multiple mitochondrial reference genes for reliable host species identification.

The distribution of mosquitoes across an altitudinal gradient in the Galapagos Islands.

An avian malaria parasite (genus Plasmodium) has been detected consistently in the Galapagos Penguin (Spheniscus mendiculus) and less frequently in some passerines. We sampled three resident mosquito species (Aedes taeniorhynchus, Culex quinquefasciatus, and Aedes aegypti) using CDC light and gravid traps on three islands in 2012, 2013, and 2014. We sampled along altitudinal gradients to ask whether there are mosquito-free refugia at higher elevations as there are in Hawaii. We captured both Ae. taeniorhynchus and Cx. quinquefasciatus at all sites. However, abundances differed across islands and years and declined significantly with elevation. Aedes aegypti were scarce and limited to areas of human inhabitation. These results were corroborated by two negative binomial regression models which found altitude, year, trap type, and island as categorized by human inhabitation to be significant factors influencing the distributions of both Ae. taeniorhynchus and Cx. quinquefasciatus. Annual differences at the highest altitudes in Isabela and Santa Cruz indicate the lack of a stable highland refuge if either species is found to be a major vector of a parasite, such as avian malaria in Galapagos. Further work is needed to confirm the vector potential of both species to understand the disease dynamics of avian malaria in Galapagos.

Seroprevalence of malarial antibodies in Galapagos penguins (Spheniscus mendiculus).

A parasite species of the genus Plasmodium has recently been documented in the endangered Galapagos penguin (Spheniscus mendiculus). Avian malaria causes high mortality in several species after initial exposure and there is great concern for the conservation of the endemic Galapagos penguin. Using a Plasmodium spp. circumsporozoite protein antigen, we standardized an enzyme-linked immunosorbent assay to test the level of exposure in this small population, as indicated by seroprevalence. Sera from adult and juvenile Galapagos penguins collected between 2004 and 2009 on the Galapagos archipelago were tested for the presence of anti- Plasmodium spp. antibodies. Penguins were also tested for the prevalence of avian malaria parasite DNA using a polymerase chain reaction (PCR) screening. Total seroprevalence of malarial antibodies in this sample group was 97.2%, which suggests high exposure to the parasite and low Plasmodium-induced mortality. However, total prevalence of Plasmodium parasite DNA by PCR screening was 9.2%, and this suggests that parasite prevalence may be under-detected through PCR screening. Multiple detection methods may be necessary to measure the real extent of Plasmodium exposure on the archipelago.