Degree of Dietary Specialization on Furanocoumarin-Containing Hostplants in a Newly Invasive Web Building Caterpillar.

The genus Depressaria (Lepidoptera: Depressariidae) mostly comprises specialist herbivores with varying capacity for detoxification of defensive phytochemistry. Depressaria depressana, a Eurasian moth recently introduced into North America, is a family-level specialist of the Apiaceae, whose hosts include more than a dozen species in multiple tribes; Depressaria radiella is a super-specialist of Eurasian origin that feeds exclusively on species in the genera Pastinaca and Heracleum throughout its native and introduced range. In eastern North America, it feeds upon Pastinaca sativa, an invasive European species, and Heracleum maximum, a native species. We determined whether differences in furanocoumarin metabolism exist between D. depressana and two isolated populations of D. radiella, feeding exclusively on either P. sativa or H. maximum. We also compared gravimetric estimates of feeding efficiency to assess D. depressana larval performance on different diets. Both populations of D. radiella metabolized furanocoumarins at a greater rate than D. depressana. Although there was no difference in rates of metabolism of linear furanocoumarins in the two populations of D. radiella, individuals collected from H. maximum metabolized angular furanocoumarins more rapidly. The gravimetric assessments of feeding efficiencies revealed that D. depressana exhibited highest efficiencies consuming Daucus carota; moreover, this species survived to pupation consuming fruits of Zizia aurea, an apiaceous species native to North America. Our preliminary phylogenetic analysis, building on an earlier morphological analysis, incorporates mitochondrial cytochrome oxidase subunit 1 data from the BOLD database and revealed that the presence or absence of furanocoumarins is not a strong predictor of species-level evolution in Depressaria.

Genetic Structure and Colonization of North America by Depressaria depressana (Fabricius 1775) (Lepidoptera: Depressariidae) over 15 Years; Contrasts with Westward Expansion of Depressaria radiella (Goeze, 1783) over 160 Years.

Depressaria depressana, the purple carrot seed moth, is a Eurasian species first reported in North America in 2008 and currently undergoing range expansion. This invasion follows that of its Eurasion congener Depressaria radiella (parsnip webworm), first documented in North America 160 years ago. Unlike D. depressana, which utilizes hostplants across multiple tribes of Apiaceae, Depressaria radiella is a "superspecialist" effectively restricted in its native and non-indigenous ranges to two closely related apiaceous genera. We investigated the genetic structure of D. depressana populations across latitudinal and longitudinal gradients in the eastern United States by constructing COI haplotype networks and then comparing these with haplotype networks constructed from available COI sequence data from contemporary European D. depressana populations and from European and North American D. radiella populations. Haplotype data revealed higher genetic diversity in D. depressana, indicating high dispersal capacity, multiple introductions, and/or a genetically diverse founding population. Museum and literature records of D. radiella date back to 1862 and indicate that range expansion to the West Coast required more than 50 years. Higher levels of genetic diversity observed in D. depressana compared to its congener may indicate a greater propensity for dispersal, colonization and establishment in its non-indigenous range.

Inferring Evolutionary Timescales without Independent Timing Information: An Assessment of "Universal" Insect Rates to Calibrate a Collembola (Hexapoda) Molecular Clock.

Previous estimates of nucleotide substitution rates are routinely applied as secondary or "universal" molecular clock calibrations for estimating evolutionary timescales in groups that lack independent timing information. A major limitation of this approach is that rates can vary considerably among taxonomic groups, but the assumption of rate constancy is rarely evaluated prior to using secondary rate calibrations. Here I evaluate whether an insect mitochondrial DNA clock is appropriate for estimating timescales in Collembola-a group of insect-like arthropods characterized by high levels of cryptic diversity. Relative rates of substitution in cytochrome oxidase subunit 1 (COI) were inferred via Bayesian analysis across a topologically constrained Hexapod phylogeny using a relaxed molecular clock model. Rates for Collembola did not differ significantly from the average rate or from the rates estimated for most other groups (25 of 30), suggesting that (1) their apparent cryptic diversity cannot be explained by accelerated rates of molecular evolution and (2) clocks calibrated using "universal" insect rates may be appropriate for estimating evolutionary timescales in this group. However, of the 31 groups investigated, 10 had rates that deviated significantly from the average (6 higher, 4 lower), underscoring the need for caution and careful consideration when applying secondary insect rate calibrations. Lastly, this study exemplifies a relatively simple approach for evaluating rate constancy within a taxonomic group to determine whether the use of secondary rates are appropriate for molecular clock calibrations.

Fully automated sequence alignment methods are comparable to, and much faster than, traditional methods in large data sets: an example with hepatitis B virus.

Aligning sequences for phylogenetic analysis (multiple sequence alignment; MSA) is an important, but increasingly computationally expensive step with the recent surge in DNA sequence data. Much of this sequence data is publicly available, but can be extremely fragmentary (i.e., a combination of full genomes and genomic fragments), which can compound the computational issues related to MSA. Traditionally, alignments are produced with automated algorithms and then checked and/or corrected "by eye" prior to phylogenetic inference. However, this manual curation is inefficient at the data scales required of modern phylogenetics and results in alignments that are not reproducible. Recently, methods have been developed for fully automating alignments of large data sets, but it is unclear if these methods produce alignments that result in compatible phylogenies when compared to more traditional alignment approaches that combined automated and manual methods. Here we use approximately 33,000 publicly available sequences from the hepatitis B virus (HBV), a globally distributed and rapidly evolving virus, to compare different alignment approaches. Using one data set comprised exclusively of whole genomes and a second that also included sequence fragments, we compared three MSA methods: (1) a purely automated approach using traditional software, (2) an automated approach including by eye manual editing, and (3) more recent fully automated approaches. To understand how these methods affect phylogenetic results, we compared resulting tree topologies based on these different alignment methods using multiple metrics. We further determined if the monophyly of existing HBV genotypes was supported in phylogenies estimated from each alignment type and under different statistical support thresholds. Traditional and fully automated alignments produced similar HBV phylogenies. Although there was variability between branch support thresholds, allowing lower support thresholds tended to result in more differences among trees. Therefore, differences between the trees could be best explained by phylogenetic uncertainty unrelated to the MSA method used. Nevertheless, automated alignment approaches did not require human intervention and were therefore considerably less time-intensive than traditional approaches. Because of this, we conclude that fully automated algorithms for MSA are fully compatible with older methods even in extremely difficult to align data sets. Additionally, we found that most HBV diagnostic genotypes did not correspond to evolutionarily-sound groups, regardless of alignment type and support threshold. This suggests there may be errors in genotype classification in the database or that HBV genotypes may need a revision.

At the confluence of vicariance and dispersal: Phylogeography of cavernicolous springtails (Collembola: Arrhopalitidae, Tomoceridae) codistributed across a geologically complex karst landscape in Illinois and Missouri.

The processes of vicariance and dispersal are central to our understanding of diversification, yet determining the factors that influence these processes remains a significant challenge in evolutionary biology. Caves offer ideal systems for examining the mechanisms underlying isolation, divergence, and speciation. Intrinsic ecological differences among cavernicolous organisms, such as the degree of cave dependence, are thought to be major factors influencing patterns of genetic isolation in caves. Using a comparative phylogeographic approach, we employed mitochondrial and nuclear markers to assess the evolutionary history of two ecologically distinct groups of terrestrial cave-dwelling springtails (Collembola) in the genera Pygmarrhopalites (Arrhopalitidae) and Pogonognathellus (Tomoceridae) that are codistributed in caves throughout the Salem Plateau-a once continuous karst region, now bisected by the Mississippi River Valley in Illinois and Missouri. Contrasting phylogeographic patterns recovered for troglobiotic Pygmarrhopalites sp. and eutroglophilic Pogonognathellus sp. suggests that obligate associations with cave habitats can restrict dispersal across major geographic barriers such as rivers and valleys, but may also facilitate subterranean dispersal between neighboring cave systems. Pygmarrhopalites sp. populations spanning the Mississippi River Valley were estimated to have diverged 2.9-4.8 Ma, which we attribute to vicariance resulting from climatic and geological processes involved in Mississippi River Valley formation beginning during the late Pliocene/early Pleistocene. Lastly, we conclude that the detection of many deeply divergent, morphologically cryptic, and microendemic lineages highlights our poor understanding of microarthropod diversity in caves and exposes potential conservation concerns.

A new endemic species of Willowsia from Florida (USA) and descriptive notes on all New World Willowsia (Collembola: Entomobryidae).

Four species of Willowsia have been reported from the Americas (W. buski, W. jacobsoni, W. mexicana, and W. nigromaculata), and to date, W. mexicana is the only member of the genus endemic to the New World. Here, Willowsia pyrrhopygia sp. nov. from Florida is described. Like W. mexicana, this new species has a native New World distribution and uninterrupted rib scale type, but can be separated by color pattern and chaetotaxy. Dorsal head chaetotaxy and other descriptive notes are provided to compliment to descriptions for W. buski, W. jacobsoni, W. mexicana, and W. nigromaculata. Comparative morphological analysis also reveals two unique character states among Entomobryinae-the outer maxillary lobe with two (not three) sublobal hairs and the absence of labial triangle seta r-shared only by endemic New World Willowsia and Americabrya, providing preliminary support for their independent evolution from a common New World ancestor.

A reassessment of the phylogenetic utility of genus-level morphological characters in the family Bogidiellidae (Crustacea, Amphipoda), with description of a new species of Eobogidiella Karaman, 1981.

Bogidiellidae is the most diverse and cosmopolitan family of stygobiotic amphipods, and inhabits a variety of subterranean biotopes, especially interstitial habitats. While the family is characterized by considerable sexual dimorphism, this dimorphism has adversely affected our understanding of the systematics of the group. Most species have restricted geographic ranges and occur in difficult to sample habitats, so it is common for individual species descriptions to be based on a single sex. In this work we revisit an analysis of morphological characters in an attempt to clarify their phylogenetic utility in resolving taxonomic relationships among genera by introducing a new species, two additional characters, and phylogenetic statistical support values. Eobogidiella venkataramani sp. n., from a spring fed brook in the Shirawati River basin along the escarpment of the Western Ghats (Karnataka, India) differs from the only known congener, Eobogidiella purmamarcensis, from Argentina, in the structure of mouthparts, the shape and ornamentation on gnathopods and characters of the telson. Our phylogenetic analyses indicate that the available morphological characters are not sufficient to resolve phylogenetic relationships within Bogidiellidae, thus these characters alone cannot be used to determine the phylogenetic placement of Eobogidiella venkataramani sp. n. within the family. Nevertheless, Eobogidiella venkataramani sp. n. shares diagnostic characters with Eobogidiella, supporting placement of the new species in this genus. Our findings point towards a critical need to resolve relationships within the family using molecular approaches, along with the development of a suite of additional morphological characters for Bogidiellidae. This is the third species of Bogidiellidae from southern India.

Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola, Entomobryidae), including four new species.

The chaetotaxy of 15 species of eastern North American Entomobrya is redescribed in order to determine potential characters for the diagnosis of cryptic lineages and evaluate the diagnostic and phylogenetic utility of chaetotaxy. As a result, four new species (Entomobrya citrensis Katz & Soto-Adames, sp. n., Entomobrya jubata Katz & Soto-Adames, sp. n., Entomobrya neotenica Katz & Soto-Adames, sp. n. and Entomobrya unifasciata Katz & Soto-Adames, sp. n.) are described, and new diagnoses are provided for Entomobrya assuta Folsom, Entomobrya atrocincta Schött, Entomobrya decemfasciata (Packard), Entomobrya ligata Folsom, Entomobrya multifasciata (Tullberg), and Entomobrya quadrilineata (Bueker). Furthermore, previously undocumented levels of intraspecific variation in macrosetal pattern are reported, tempering the exclusive use of chaetotaxy for species delimitation. Phylogenetic relationships, estimated using both morphological and molecular data, indicate that Entomobrya is likely paraphyletic. The phylogenies also suggest that unreliable character homology, likely fostered by Entomobrya's profusion of macrosetae, may limit the phylogenetic utility of chaetotaxy in groups characterized by an abundance of dorsal macrosetae.