Mosquito-host blood-meal networks reveal potential arboviral bridge pathways in Colombian Caribbean mangroves.

Mosquito-host feeding networks shape the ecological routes through which arboviruses may move from enzootic cycles toward human-exposure compartments, yet these networks remain largely uncharacterized in Colombian Caribbean mangroves. We analyzed blood-fed female mosquitoes collected in La Balsa, San Bernardo del Viento (Córdoba, Colombia), between 2011 and 2014 to infer a molecular blood-meal-based interaction network. Of 496 blood-fed females from nine mosquito species, 437 amplified by CytB and/or COI PCR and 396 yielded high-quality sequences suitable for host identification, resolving 31 vertebrate host taxa. Birds dominated successful host assignments (275/396; 69.4%), whereas human feeding was concentrated in Aedes aegypti (HBI = 0.75; 95% CI: 0.47-0.91) and Aedes scapularis (HBI = 0.22; 95% CI: 0.09-0.45). Bray-Curtis clustering identified an ornithophagic Culex guild, an exploratory mixed mammal-bird bridge grouping, and an anthropophagic/mammalophagic Aedes guild, with bootstrap support of 84.6%, 47.4%, and 98.3%, respectively. The directed, weighted network contained 40 nodes and 63 feeding links, with high topological complexity (0.9621) and central bridge nodes including Cx. erraticus, Ma. titillans, De. atlanticus, and Ps. confinnis. Complementary R/bipartite analysis indicated a generalist but partially structured network: connectance = 0.2258, generality = 7.0 host taxa per mosquito species, vulnerability = 2.03 mosquito species per host taxon, H2' = 0.421, QuanBiMo Q = 0.378, NODF = 29.73, and weighted NODF = 19.83. Arbovirus screening of these blood-fed specimens was negative, so the network should be interpreted as a map of potential ecological pathways rather than confirmed transmission. Low HBI outside the anthropophagic guild and high non-human host use are consistent with a dilution-effect hypothesis in intact mangroves, while the identified bridge pathways highlight mosquito-host relationships that could connect enzootic and peridomestic compartments if viral circulation increases or habitat structure changes.