Search

Despite their status as economically important pests on apple, species boundaries in the four native Nearctic species of Pandemis Hübner have remained uncertain for a century. We use a total evidence approach to test their genomic integrity using DNA (cytochrome oxidase I and ITS2), morphological (greyness of various wing areas), and geographic evidence. No single source of characters is sufficient, but combined evidence successfully separates the four species. We also examine the generic boundaries of Pandemis, using all Nearctic species, most western Palaearctic species, and a species of Archepandemis. DNA data place Archepandemis within Pandemis indicating that its members have lost the secondary sexual characters found in other Pandemis species.

Coneworms of the genus Dioryctria Zeller include several serious pests of conifer seeds that are notoriously difficult to distinguish as species. We surveyed mitochondrial DNA variation within the abietella species group by sequencing 451 bp of cytochrome oxidase subunit 1 (COI) and 572 bp of cytochrome oxidase subunit 2 (COII) genes from 64 individuals of six major species in the group. In addition to examining phylogenetic relationships within European members of the group, the study focused on the two most damaging species, D. abietivorella Grote from North America and D. abietella Denis & Schiffermuller from Europe and Asia, which have been considered taxonomically synonymous in the past. To detect different levels of divergence, we extensively sampled in seed orchards and natural forests for D. abietella on different hosts. Maximum parsimony and maximum likelihood analyses confirmed the monophyly of the abietella species group and its separation into three clades. The grouping of North American species (clade A) received strong support in both analyses, whereas relationships between clade A and the two European clades were weakly supported. Dioryctria simplicella Heinemann could not be unambiguously separated from D. abietella populations. The diverse haplotypes observed in the network analysis conducted with eight populations of polyphagous D. abietella suggested the presence of two distinct lineages in France.

Species of Dioryctria Zeller (Lepidoptera: Pyralidae) are important pests of conifers, particularly in seed orchards, and accurate species identification is needed for effective monitoring and control. Variable forewing morphology and lack of species-specific genitalic features hinder identification, prompting the search for additional diagnostic characters. Mitochondrial DNA (mtDNA) sequences from the cytochrome c oxidase I and II genes (COI and COII) were obtained from specimens collected at lights, pheromone traps, and host plants in the Pacific Northwest, focusing on a U.S. Forest Service seed orchard in Chico, CA. A 475-bp fragment of COI was used to identify eight distinct genetic lineages from 180 Dioryctria specimens, and these were identified as eight described species. Comparisons among mtDNA variation, adult morphology, larval host association, and pheromone attraction were used to assign individuals to species groups and to identify diagnostic characters for species identification. A ...

The white pine weevil, Pissodes strobi (Peck), is a major source of damage to young spruce and pine trees across North America. The species contains a substantial amount of genetic, morphological, and behavioral variation, and identiÞcation of patterns of genetic variation on a broad geographic scale may contribute toward more effective pest management strategies. To estimate maternal gene sow and examine the genetic structure of P. strobi we sequenced an 826-bp fragment of the mitochondrial DNA (mtDNA) COI gene in 130 individuals from 11 locations across Canada. Nested clade analysis of 36 haplotypes yielded three patterns of genetic structuring that are inferred as due primarily to restricted gene sow and contiguous range expansion, with one case of long-distance colonization. Analysis of molecular variance analysis also showed signiÞcant genetic structuring and restricted gene sow among regional populations. Eastern and western populations were divergent, as were the four populations surveyed in British Columbia. Findings were comparable with those of previous studies based on allozyme or randomly ampliÞed polymorphic DNA data, although popu- lation differentiation was greater in mtDNA. Detection of such genetic structure may be important for control programs, because other studies have shown that the conifer hosts of P. strobi provide geographically structured variation in resistance to damage.

The Holarctic Archips xylosteana Group consists of at least 18 morphologically similar species in the Nearctic, three of which were synonymized with A. argyrospila by Razowski and subsequently returned to species status, two that were described since 1986 but are clearly related to A. argyrospila, and an additional Western clade of A. argyrospila haplotypes that Razowski had not seen. We examined the morphology of all described Nearctic Xylosteana Group members plus one undescribed species, as well as DNA variation in a 816 bp segment of the mitochondrial COI gene for 17 of these species. We also examined three of five species of Archips from the Packardiana Group (=Archippus Freeman), and three outgroup genera (Argyrotaenia Stephens, Clepsis Guenee, and Choristoneura Lederer). Parsimony analyses of the combined molecular and morphological data sets gave better resolution and a better supported tree than did analyses of any single data set. All analyses revealed five species groups, rendering paraphyletic the Xylosteana Group as previously defined. An updated systematic list of Nearctic Archips is provided. We discuss the possibility that our data could support the resurrection of the genus Archippus from synonymy and the recognition of the Cerasivorana Group and the Purpurana Group as new genera. We have elected to leave the genus intact pending future investigations that include the additional Palaearctic members of the group.

The Archips argyrospila complex consists of a series of morphologically indistinct populations with a confusing array of pheromone and host types. No phylogenetic studies on the genus Archips or any of its species groups have previously been published. We examined DNA variation in a 475 bp segment of the mitochondrial COI gene and compared 30 populations of A. argyrospila, four populations of A. mortuana, four populations of A. goyerana, and one specimen of each of four outgroup species. Among the 97 ingroup sequences obtained, there were 23 unique haplotypes and nucleotide variation at 20 sites. The monophyletic ingroup containing A. argyrospila, A. mortuana, A. goyerana and a West Coast clade was strongly supported by bootstrap values and decay indices. Host races and some pheromone types within A. argyrospila did not correspond to mtDNA variation in this analysis. Our molecular analyses supported phylogenetic and ecological interpretations of species status applied to A. goyerana but not A. mortuana, and supported the existence of a phylogenetically distinct West Coast species.

Moths of the Argyrotaenia franciscana species group represent a challenging case of evolutionary lability and taxonomic complexity in California. We studied their evolutionary rela- tionships using mitochondrial DNA (mtDNA) sequences from 49 specimens in 18 populations of the A. franciscana group, as well as 2 outgroup species. Most specimens were sequenced over a 799-bp segment of the cytochrome oxidase subunit I (COI) gene. Single specimens each of A. franciscana insulana Powell and A. citrana (Fernald) were sequenced over a 2.3-kb region including COI, tRNA leucine (UUR), and cytochrome oxidase subunit II (COII). mtDNA variation within and among Argyrotaenia citrana, A. franciscana (Walsingham), and A. franciscana insulana is most simply interpreted as DNA polymorphism within a single species for which the oldest name is A. franciscana. Maximal divergence among haplotypes was 3.8%, which is on the high end of the range for intraspecificmtDNAvariationinLepidoptera. Argyrotaenianiscana (Kearfott)ismostcloselyrelated to a new species, and this pair forms the closest outgroup to the A. franciscana-citrana complex. The status of A. isolatissima Powell remains uncertain.

The six extant species of Limnoporus water striders provide an unusual opportunity to compare allozyme and mitochondrial DNA (mtDNA) divergences with both morphological divergences and information on interspecific hybrid inviability. Parsimony analyses of mtDNA, allozymes, and morphology did not differ greatly, and each data type provided useful information on at least some nodes in the phylogeny. Simultaneous analysis of the combined data gave a better resolved and supported tree than did any single data type. Several measures of hybrid inviability bore no relationship to genetic distances between species, thus demonstrating the poor value of hybrid compatibility as an indicator of phylogenetic relationships. When genetic distances were related to estimates of time of divergence based on fossils, standard molecular clocks for mtDNA and allozymes showed as much as a 10-fold underestimate of absolute time. The phylogeny of Limnoporus allows more rigorous evaluation of several prior hypotheses of ecological or developmental processes in water striders. In particular, the phylogeny supports the evolutionary lability of wing dimorphism, sexual size dimorphism, and local differentiation of ontogenetic traits.

Three sibling species of European small ermine moths of the Yponomeuta padella complex have been collected in North America. To allow identification of fresh as well as dried specimens without host data, we examined these three species for diagnostic differences in their mitochondrial DNA (mtDNA). We report the sequence for a 2.3-kb region of mtDNA that includes the cytochrome oxidase I and II and transfer RNA (tRNA) leucine genes. The mtDNA of Y. malinellus Zeller showed 0.8-0.9% divergence from that of the other two species, Y. padella (L.) and Y. cagnagella (H¼bner). The latter two species had divergences of only 0.0-0.2;%. A survey of restriction sites in 44 collections demonstrated that Y. malinellus has distinct, diagnosable mtDNA in North America, whereas Y. padella and Y. cagnagella were not distinguished from each other by this method. The recent establishment and range expansion of Y. malinellus and Y. padella in western North America is currently being monitored by pheromone traps that potentially have some degree of cross-attraction. Restriction sites in amplified mtDNA should allow rapid confirmation of species identities of such dried collections. The method used to generate the particular diagnostic reported here can be expanded readily to include new species and populations.