Efficient Monitoring of Adult and Immature Mosquitoes Through Metabarcoding of Bulk Samples: A Case Study for Non-Model Culicids With Unique Ecologies.

The rapid and economical monitoring of mosquitos is imperative to understanding the dynamics of both disease vectors and nuisance species. In light of technological advances in mosquito sampling and DNA sequencing, health agencies can now utilize the full potential of metabarcoding pipelines for rapid and standardizable surveillance. Here, we describe mosquito spatial and temporal variation, with particular focus on Mansonia Blanchard species, in the Madeira (Rondônia State) and the Ribeira (São Paulo) watersheds, Brazil using metabarcoding of the D2 rDNA marker. Sampling and molecular pipelines were used to evaluate the taxonomic contribution of mosquitos in pools of culicids collected en masse from macrophyte-roots (immatures) and from Mosquito Magnet traps and protected human landings (adults). Results for adult captures are comparable to morphological diagnoses and clarify previously unknown temporal and spatial species turnover. Metabarcoding of immature stages also confirmed the extent of the geographical distribution of some species and each taxon's association with macrophyte species. Given the benefits of metabarcoding, such as taxonomic acuity, high throughput processing, and objectivity, we suggest such techniques should be more fully incorporated into culicid monitoring schemes. The metabarcoding protocol described herein paired with standardized field sampling schemes, when used by mosquito monitoring professionals, offers substantial improvements in terms of practicality, speed and cost.

Larvicide Activity on Aedes aegypti of Essential Oil Nanoemulsion from the Protium heptaphyllum Resin.

The aim of this work was to prepare a nanoemulsion containing the essential oil of Protium heptaphyllum resin and to evaluate the larvicidal activity and the residual larvicidal effect against Aedes aegypti. The essential oil was identified by gas chromatography coupled to a mass spectrometer, and the nanoemulsions were prepared using a low-energy method and characterized by photon correlation spectroscopy. The results indicated the major constituents as p-cimene (27.70%) and α-Pinene (22.31%). Nanoemulsions had kinetic stability and a monomodal distribution in a hydrophilic-lipophilic balance of 14 with particle diameters of 115.56 ± 1.68 nn and zeta potential of -29.63 ± 3.46 mV. The nanoemulsion showed larvicidal action with LC50 = 2.91 µg∙mL-1 and residual larvicidal effect for 72 h after application to A. aegypti larvae. Consequently, the nanobiotechnological product derived from the essential oil of P. heptaphyllum resin could be used against infectious disease vectors.