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Bichromomyia flaviscutellata (Mangabeira, 1942) sensu stricto (Diptera: Psychodidae) has been recognized as the main vector of Leishmania amazonensis in the Brazilian Amazon. For this reason, it is of paramount importance to understand the distribution of genetic diversity of populations of this vector, particularly the genetic structure and gene flow, for its management and control efforts. This study investigated the phylogeographic structure of five B. flaviscutellata s.s. populations from the central Brazilian Amazon region by analyzing 1,141 bp fragment of the 3' region of the COI gene. A total of 85 specimens of B. flaviscutellata s.s. were sequenced from Manaus (14), Rio Preto da Eva (10), Pitinga (14), Novo Airão (21), and Autazes (26); all in the state of Amazonas. The dataset yielded 59 haplotypes, most of them connected to each other in the main network. There were high levels of intrapopulation genetic variability (h = 0.945 ± 0.035 - 0.978 ± 0.054). The genetic distance values among populations varied from moderate (0.0873) to very high (0.3535), and all comparisons were significant, as well as the hierarchical analysis (ΦST = 0.2145). In contrast, these comparisons revealed a high number of shared sites (Ss = 6-34) and no difference in fixed sites (Sf = 0) among populations indicating absence of historical isolation. The Mantel test indicated that 67.92% (r = 0.6792; P = 0.06) of the genetic structure observed in B. flaviscutellata s.s. cannot be explained by the isolation-by-distance (IBD) model. This genetic structure, weakly explained by the IBD, may be due mainly by the forest habitat fragmentation and the low dispersal (flight) capacity of sand flies. Both factors could lead to population fragmentation and isolation, which promote genetic differentiation. Taken together, these findings suggest that the genetic structure observed in the studied populations of B. flaviscutellata s.s. is likely generated by microevolutionary processes acting at the population level at the present time and, therefore, evolutionary lineages were not recognized among the populations analyzed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The eggs of three Amazonian species of the genus Mansonia (Diptera: Culicidae) were analyzed using morphological and morphometric characters. Eggs of Mansonia humeralis Dyar & Knab, 1916 were morphologically different from those of Mansonia titillans (Walker, 1848) and Mansonia amazonensis (Theobald, 1901), which were more similar to each other according to linear and geometric morphometry. A principal component analysis generated from elliptic Fourier contour data (PC1-92.6% and PC2-2.61%) indicated that Ma. amazonensis and Ma. titillans are more similar to each other than either is to Ma. humeralis. Discriminant multivariate analysis was highly accurate with only four classification errors and a 90% accuracy rate. The results indicate that the three Amazonian species can be precisely distinguished in the egg stage and that geometric morphometry based on elliptic Fourier contours is a promising method for distinguishing eggs of species of Mansonia. An identification key based on egg morphology is provided to distinguish the four Neotropical species., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Genetic variability and divergence were estimated for populations of Anopheles rangeli Gabaldón, Cova-Garcia & Lopes, Anopheles nuneztovari Gabald6n cytotype A, and Anophels dunhami Causey from the Brazilian Amazon using isozyme electrophoresis. These species are included in the Oswaldoi subgroup, subgenus Nyssorhynchus (Diptera: Culicidae). Thirteen enzymes yielded a total of 22 loci, of which 14 were monomorphic in the three species. Three diagnostic loci (Gpi-1, Hk-1, and Me) and a strong differentiation in the Mdh locus were found between An. rangeli and An. nuneztovari. Five diagnostic loci (Mdh, Gpi-l, Hk-1, Gpd, and Me) separated An. rangeli from An. dunhami, whereas one diagnostic locus (Gpd) separated An. nuneztovari from An. dunhami. Moderate differentiation was observed in the Est-5 and Pgm loci between An. rangeli and An. nuneztovari, and between An. nuneztovari and An. dunhami. Anopheles dunhami had the highest values for three indices of genetic variability, whereas An. rangeli showed the lowest values for mean number of alleles per locus and mean heterozygosity. Nei's genetic distance was highest between An. rangeli and An. dunhami (0.280) and lowest between An. nuneztovari and An. dunhami (0.072). Between An. rangeli and An. nuneztovari the genetic distance was 0.237. Anopheles dunhami and An. nuneztovari are sister species very closely related and may have a recent evolutionary origin. Anopheles rangeli probably diverged before the other two species separated. This is the first record of An. dunhami in Coari (Amazonas, Brazil) and only the third collection site of this species since its description in 1945.