Introduction: Amblyomma cajennense sensu lato represents a significant challenge for sustainable tick control in tropical cattle systems due to its ecological adaptability, wide host range, and frequent co-occurrence with Rhipicephalus microplus . This study evaluated the occurrence of acaricide resistance in A. cajennense s.l. populations collected from cattle farms in coastal Ecuador. Methods: A cross-sectional field assessment was conducted on seven farms (Esmeraldas, n = 2; Manabí, n = 5) that met the minimum requirement of 30 engorged A. cajennense s.l. females per farm for resistance testing. Tick larvae were subjected to larval packet tests to determine susceptibility to three commonly used acaricides: amitraz, ivermectin, and alpha-cypermethrin. Results: Phenotypic resistance to at least one acaricide was detected on all evaluated farms. Resistance prevalence was 43% for amitraz, 86% for ivermectin, and 100% for alpha-cypermethrin. Multi-resistance occurred on 86% of farms. Estimated lethal dose values revealed extremely high LD₉₀ and LD₉₉ levels, frequently exceeding recommended commercial concentrations by several orders of magnitude. Exploratory screening suggested that extensive cattle production systems and the presence of alternative hosts, particularly horses and other equids, may contribute to resistance emergence and persistence. Discussion: The results are particularly relevant because A. cajennense s.l. frequently co-occurs with R. microplus on cattle farms, although the two species differ substantially in ecology, host use, and life cycle. Control strategies primarily designed for R. microplus , such as whole-animal acaricide treatments, may have limited impact on Amblyomma populations maintained through wildlife hosts and environmental stages. This study provides the first evidence of acaricide resistance in A. cajennense s.l. in Ecuador and highlights the need for species-specific management strategies, improved resistance monitoring, and integrated tick control programs adapted to multi-species infestations in tropical livestock systems.

Phytotelmata are natural water-holding microhabitats that support diverse aquatic communities, including immature mosquitoes. We analyzed the diversity, composition, and interaction network structure of Culicidae associated with two bromeliad species, Aechmea distichantha and Vriesea friburgensis, in two localities of the Yungas ecoregion in northwestern Argentina: La Florida Provincial Reserve (LFPR) (Tucumán) and Isla de Cañas (Salta). Immature mosquitoes were sampled during 2017–2018, and community structure was evaluated using Hill numbers, nonparametric richness estimators, bipartite network analysis, and canonical correspondence analysis (CCA). A total of 12 mosquito species were identified, with richness ranging from 5 to 9 species depending on bromeliad species and locality, with the highest richness recorded in V. friburgensis in LFPR. Sampling completeness ranged from 96.8% to 100%. Bipartite network analysis showed moderate connectance (0.50), low modularity (Q = 0.188), intermediate nestedness (NODF = 46.94), and low global specialization (H2′ = 0.273), suggesting a relatively generalized interaction structure. Culex coronator and Cx. imitator dominated the assemblage, while other species exhibited more restricted associations. The CCA indicated that species composition was mainly associated with bromeliad height above ground, internal water temperature, sediment, and pH. These results highlight the importance of microhabitat heterogeneity in structuring mosquito assemblages in Neotropical phytotelmata.

Phytotelmata are natural water-holding microhabitats that support diverse aquatic communities, including immature mosquitoes. We analyzed the diversity, composition, and interaction network structure of Culicidae associated with two bromeliad species, Aechmea distichantha and Vriesea friburgensis, in two localities of the Yungas ecoregion in northwestern Argentina: La Florida Provincial Reserve (LFPR) (Tucumán) and Isla de Cañas (Salta). Immature mosquitoes were sampled during 2017-2018, and community structure was evaluated using Hill numbers, nonparametric richness estimators, bipartite network analysis, and canonical correspondence analysis (CCA). A total of 12 mosquito species were identified, with richness ranging from 5 to 9 species depending on bromeliad species and locality, with the highest richness recorded in V. friburgensis in LFPR. Sampling completeness ranged from 96.8% to 100%. Bipartite network analysis showed moderate connectance (0.50), low modularity (Q = 0.188), intermediate nestedness (NODF = 46.94), and low global specialization (H2’=0.273), suggesting a relatively generalized interaction structure. Culex coronator and Cx. imitator dominated the assemblage, while other species exhibited more restricted associations. The CCA indicated that species composition was mainly associated with bromeliad height above ground, internal water temperature, sediment, and pH. These results highlight the importance of microhabitat heterogeneity in structuring mosquito assemblages in Neotropical phytotelmata.

Malaria continues to be one of the major global health burdens despite worldwide efforts to reduce its incidence and prevalence. Recent technological advances have generated new mosquito-control alternatives, one of which involves the use of symbionts that are part of the core gut microbiota to develop paratransgenesis strategies. This exploratory study characterized the bacterial community of Anopheles argyritarsis and Anopheles pseudopunctipennis across three environments: Iruya River (mountain forest), Conchas River (transitional zone), and Chirimayo River (agricultural landscape). Through 16S rRNA gene sequencing, we obtained 1,308 amplicon sequence variants (ASVs). We registered dominance of the phyla Proteobacteria (94%) and Bacteroidota (3.28%). At the genus level, Thorsellia was the dominant taxon within the core microbiota (71.5%). Shannon (5.09–5.95) and Simpson (0.988–0.996) diversity indices indicated that, despite the increase of multiple bacterial genera in anthropized areas, community evenness remained balanced. Meanwhile, beta diversity analysis (Bray-Curtis) demonstrated that both host species and sampling area influenced bacterial composition. These results are presented within a descriptive and exploratory framework due to the limited replication across species-locality combinations. Despite the challenge of establishing host-symbiont relationships, Thorsellia is a genus that warrants further tracking across different developmental stages based on its notable stability in this study. Under the holobiont perspective, understanding how the microbiota influences vector fitness, longevity, and resilience will help guide different efforts toward control and surveillance strategies across ecological settings for future investigations. Although Argentina has not reported autochthonous malaria cases, the vector persists and the risk of re-emergence remains latent.