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The tribe Aedini (Family Culicidae) contains approximately one-quarter of the known species of mosquitoes, including vectors of deadly or debilitating disease agents. This tribe contains the genus Aedes, which is one of the three most familiar genera of mosquitoes. During the past decade, Aedini has been the focus of a series of extensive morphology-based phylogenetic studies published by Reinert, Harbach, and Kitching (RH&K). Those authors created 74 new, elevated or resurrected genera from what had been the single genus Aedes, almost tripling the number of genera in the entire family Culicidae. The proposed classification is based on subjective assessments of the "number and nature of the characters that support the branches" subtending particular monophyletic groups in the results of cladistic analyses of a large set of morphological characters of representative species. To gauge the stability of RH&K's generic groupings we reanalyzed their data with unweighted parsimony jackknife and maximum-parsimony analyses, with and without ordering 14 of the characters as in RH&K. We found that their phylogeny was largely weakly supported and their taxonomic rankings failed priority and other useful taxon-naming criteria. Consequently, we propose simplified aedine generic designations that 1) restore a classification system that is useful for the operational community; 2) enhance the ability of taxonomists to accurately place new species into genera; 3) maintain the progress toward a natural classification based on monophyletic groups of species; and 4) correct the current classification system that is subject to instability as new species are described and existing species more thoroughly defined. We do not challenge the phylogenetic hypotheses generated by the above-mentioned series of morphological studies. However, we reduce the ranks of the genera and subgenera of RH&K to subgenera or informal species groups, respectively, to preserve stability as new data become available.

We used two mitochondrial loci (nicotinamide adenine dinucleotide dehydrogenase subunit 4 and cytochrome oxidase II) and a nuclear locus (28S-D2 spacer) for a total of 1337 bp to evaluate the relationships among the four subspecies of Aedes (Finlaya) japonicus Theobald. Ae. j. japonicus was recently introduced into the United States and has been expanding rapidly. We also included in our analysis a morphologically very closely related species, Aedes (Finlaya) koreicus Edwards, as well as three more distantly related species: Aedes (Finlaya) togoi Theobald, Aedes (Finlaya) hatorii Yamada, and Aedes (Aedimorphus) vexans Meigen. We found that the four subspecies in the Ae. japonicus complex are genetically quite distinct but seem to form a monophyletic group that surprisingly also includes Ae. koreicus, suggesting the need for a taxonomic reconsideration of the group. We also found that the two southern subspecies are more closely related to each other than to any of the remaining subspecies or to Ae. koreicus and may indicate an ancient north-south split of the lineage. Considering the overlap between Ae. j. japonicus and Ae. koreicus, but the stronger association between Ae. koreicus and humans, we are surprised it also has not expanded from its original range. As a proactive reaction to this possibility, we designed and tested a DNA-based rapid assay to differentiate Ae. koreicus from some of the species with which it may be confused in the United States. These Aedes are putative vectors of several important viral encephalitides.

Introduction of potential disease vectors into a new geographic area poses health risks to local human, livestock, and wildlife populations. It is therefore important to gain understanding of the dynamics of these invasions, in particular its sources, modes of spread after the introduction, and vectorial potential. We studied the population genetics of Aedes (Finlaya) japonicus japonicus (Theobald), an Asian mosquito that was recognized for the first time in the United States in 1998. We examined patterns of genetic diversity using random amplified polymorphic DNA and sequences of ND4 of mtDNA by comparing samples from populations spanning the range of this mosquito in Japan (six samples) and the United States (nine samples) as well as specimens intercepted in New Zealand in 1999. We found geographically differentiated populations in Japan, indicating limited gene flow even on small spatial scales. In the United States, we found evidence of significant genetic differentiation between samples from New York, Connecticut, and New Jersey and those from mid-Pennsylvania and Maryland. We were unable to pinpoint the source location(s) in Japan, although some of the U.S. samples are genetically close to samples from south Honshu and western Kyushu. Further studies should include samples from Korean populations. Distinct genetic signatures in U.S. populations undergoing expansion suggest the possibility of local increases in genetic diversity if and where they meet.

Repellent efficacy of N,N-diethyl-3-methyl-benzamide (deet), the piperidine, 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine (AI3-37220), and a 1:1 ratio of deet + AI3-37220 were evaluated topically (0.25 mg/cm2 applied in ethanol solution) on human volunteers against the mosquito Aedes communis (DeGeer) and the black fly Simulium venustum Say. The average repellency of all three formulations was > 95% at 4 h. For both mosquitoes and black flies, deet alone provided < 90% protection at 6 h, whereas AI3-37220 provided > 95% protection. Although repellent treatments were not significantly different overall, the contrasts between AI3-3720 versus deet were significant at 6 and 8 h. The 95% confidence interval on percent repellency at 6 h ranged from 90.1 to 98.9% for AI3-37220 versus 64.3 to 82.2% for deet, and at 8 h ranged 76.1 to 88.5% for AI3-37220 versus 47.8 to 64.0% for deet. Similarly, the confidence interval for protection against black flies at 6 h by (AI3-37220 ranged from 86.3 to 99.5% and did not overlap with the confidence interval provided by deet alone (51.2 to 78.8%). There was no evidence of synergistic repellency from a combination of the two compounds; i.e., protection from combined compounds was no better than either repellent used alone.