Barbara J. Sharanowski

Insect succession and decomposition patterns on shaded and sunlit carrion in Saskatchewan in three different seasons

A study was conducted on decomposition and insect succession in the Prairie Ecozone of Saskatchewan in the year 2000. Eighteen domestic pig carcasses (42-79 kg) were employed as human models for applications to future homicide investigations in this region. Two major variables were considered including the effect of season and habitat (sun versus shade). Research was conducted over 25 weeks, spanning three seasons: spring, summer and fall. Ambient temperature, internal carcass temperature, faunistic succession over time, and the rate of decay were all compared for each experimental variable. Results indicated that habitat was only a factor in the decompositional rate of carrion in the spring season. The ambient temperature was the chief factor determining the seasonal variations in decay rate. Maximum internal carcass temperatures always coincided with the presence of 3rd instar larvae. Patterns of insect succession occurred in a predictable sequence that varied across different habitats and seasons and was unique compared to previously published studies. Carcasses placed in spring and fall attracted a more diverse assemblage of insects than summer-placed carrion. Sun-exposed carrion also had greater variation in fauna than shaded carrion in spring and fall. Members of Silphidae were the first coleopteran colonizers in all habitats and seasons. This paper also marks the first record for Cochliomyia macellaria (Fabricius) in Saskatchewan.

Molecular phylogenetics of Braconidae (Hymenoptera: Ichneumonoidea), based on multiple nuclear genes, and implications for classification

This study examined subfamilial relationships within Braconidae, using 4 kb of sequence data for 139 taxa. Genetic sampling included previously used markers for phylogenetic studies of Braconidae (28S and 18S rDNA) as well as new nuclear protein‐coding genes (CAD and ACC). Maximum likelihood and Bayesian inference of the concatenated dataset recovered a robust phylogeny, particularly for early divergences within the family. This study focused primarily on non‐cyclostome subfamilies, but the monophyly of the cyclostome complex was strongly supported. There was evidence supporting an independent clade, termed the aphidioid complex, as sister to the cyclostome complex of subfamilies. Maxfischeria was removed from Helconinae and placed within its own subfamily within the aphidioid complex. Most relationships within the cyclostome complex were poorly supported, probably because of lower taxonomic sampling within this group. Similar to other studies, there was strong support for the alysioid subcomplex containing Gnamptodontinae, Alysiinae, Opiinae and Exothecinae. Cenocoeliinae was recovered as sister to all other subfamilies within the euphoroid complex. Planitorus and Mannokeraia, previously placed in Betylobraconinae and Masoninae, respectively, were moved to the Euphorinae, and may share a close affiliation with Neoneurinae. Neoneurinae and Ecnomiinae were placed as tribes within Euphorinae. A sister relationship between the microgastroid and sigalphoid complexes was also recovered. The helconoid complex included a well‐supported lineage that is parasitic on lepidopteran larvae (macrocentroid subcomplex). Helconini was raised to subfamily status, and was recovered as sister to the macrocentroid subcomplex. Blacinae was demoted to tribal status and placed within the newly circumscribed subfamily Brachistinae, which also contains the tribes Diospilini, Brulleiini and Brachistini, all formerly in Helconinae.

Revision of the Agathidinae (Hymenoptera: Braconidae) with comparisons of static and dynamic alignments

The phylogeny of the Agathidinae (Insecta: Hymenoptera: Braconidae) is investigated based on morphological and sequence data from the D2–3 regions of 28S rDNA. Morphology and molecular data were run simultaneously and separately and the molecular and combined data sets were analyzed using both static, Clustal W, and dynamic, POY, alignments. Both alignments were conducted under a variety of gap costs and results are compared. Sixty‐two ingroup exemplars representing 22 genera and six outgroup taxa representing two subfamilies and five genera were included. Numerous taxa at the generic and tribal levels were tested for monophyly and the evolutionary history of several characters is discussed. The tribe Agathidini s.s. is found to be a derived member of the Microdini and the two are synonymized under the older name, Agathidini s.l. Support is substantial for the tribes Cremnoptini and Disophrini and Earinini but equivocal for the Agathidini s.l. At the generic level, Bassus is found to be polyphyletic. Numerous new synonymies and combinations are proposed.

Expressed sequence tags reveal Proctotrupomorpha (minus Chalcidoidea) as sister to Aculeata (Hymenoptera: Insecta)

Hymenoptera is one of the most diverse groups of animals on the planet and have vital importance for ecosystem function as pollinators and parasitoids. Higher-level relationships among Hymenoptera have been notoriously difficult to resolve with both morphological and traditional molecular approaches. Here we examined the utility of expressed sequence tags for resolving relationships among hymenopteran superfamilies. Transcripts were assembled for 6 disparate Hymenopteran taxa with additional sequences added from public databases for a final dataset of 24 genes for 16 taxa and over 10 kb of sequence data. The concatenated dataset recovered a robust and well-supported topology demonstrating the monophyly of Holometabola, Hymenoptera, Apocrita, Aculeata, Ichneumonoidea, and a sister relationship between the two most closely related proctotrupomorphs in the dataset (Cynipoidea+Proctotrupoidea). The data strongly supported a sister relationship between Aculeata and Proctotrupomorpha, contrary to previously proposed hypotheses. Additionally there was strong evidence indicating Ichneumonoidea as sister to Aculeata+Proctotrupomorpha. These relationships were robust to missing data, nucleotide composition biases, low taxonomic sampling, and conflicting signal across gene trees. There was also strong evidence indicating that Chalcidoidea is not contained within Proctotrupomorpha.

Utility of the DNA barcoding gene fragment for parasitic wasp phylogeny (Hymenoptera: Ichneumonoidea): data release and new measure of taxonomic congruence

The enormous cytochrome oxidase subunit I (COI) sequence database being assembled from the various DNA barcoding projects as well as from independent phylogenetic studies constitutes an almost unprecedented amount of data for molecular systematics, in addition to its role in species identification and discovery. As part of a study of the potential of this gene fragment to improve the accuracy of phylogenetic reconstructions, and in particular, exploring the effects of dense taxon sampling, we have assembled a data set for the hyperdiverse, cosmopolitan parasitic wasp superfamily Ichneumonoidea, including the release of 1793 unpublished sequences. Of approximately 84 currently recognized Ichneumonoidea subfamilies, 2500 genera and 41 000 described species, barcoding 5′‐COI data were assembled for 4168 putative species‐level terminals (many undescribed), representing 671 genera and all but ten of the currently recognized subfamilies. After the removal of identical and near‐identical sequences, the 4174 initial sequences were reduced to 3278. We show that when subjected to phylogenetic analysis using both maximum likelihood and parsimony, there is a broad correlation between taxonomic congruence and number of included sequences. We additionally present a new measure of taxonomic congruence based upon the Simpson diversity index, the Simpson dominance index, which gives greater weight to morphologically recognized taxonomic groups (subfamilies) recovered with most representatives in one or a few contiguous groups or subclusters.

Quantifying the pleistocene history of the oak gall parasitoid Cecidostiba fungosa using twenty intron loci.

The longitudinal spread of temperate organisms into refugial populations in Southern Europe is generally assumed to predate the last interglacial. However, few studies have attempted to quantify this process in nonmodel organisms using explicit models and multilocus data. We used sequence data for 20 intron‐spanning loci (12 kb per individual) to resolve the history of refugial populations of a widespread western Palaearctic oak gall parasitoid Cecidostiba fungosa (Pteromalidae). Using maximum likelihood and Bayesian methods we assess alternative population tree topologies and estimate divergence times and ancestral population sizes under a model of divergence between three refugia (Middle East, Balkans and Iberia). Both methods support an “Out of the East” history for C. fungosa, matching the pattern previously inferred for their gallwasp hosts. However, coalescent‐based estimates of the ages of population divides are much more recent (coinciding with the Eemian interglacial) than nodal ages of single gene trees for C. fungosa and other species. We also find that increasing the sample size from one haploid sequence per refugial population to three only marginally improves parameter estimates. Our results suggest that there is significant information in the minimal samples currently analyzable with maximum likelihood methods, and that similar methods could be applied to multiple species to test alternative models of assemblage evolution.

Developing EPIC markers for chalcidoid Hymenoptera from EST and genomic data

Increasing numbers of phylogeographic studies make comparative inferences about the histories of co‐distributed species. Although the aims of such studies are best achieved by jointly analysing sequences from multiple loci in a model‐based framework, such data currently exist for few nonmodel systems. We used existing genomic data and expressed sequence tags (ESTs) for Hymenoptera and other insects to design intron‐crossing primers for 40 loci, mainly ribosomal proteins, for chalcidoid parasitoids. Amplification success was scored on a range of taxa associated with two natural communities; oak galls and figs. Taxa were chosen at increasing distance from Nasonia, which was used for primer design, (i) within Pteromalids, (ii) within Chalcidoidea (Eupelmidae, Eulophidae, Eurytomidae, Ormyridae, Torymidae) and (iii) for a selection of distantly related gall and fig wasps (Cynipidae, Agaonidae). To assess the utility of these loci for phylogeographic and population genetic studies, we compared genetic diversity between Western Palaearctic refugia for two species. Our results show that it is feasible to design a large number of exon‐primed‐intron‐crossing (EPIC) loci that may be informative about phylogeographic history within species but amplify across a large taxonomic range.

Maxfischeriinae: a new braconid subfamily (Hymenoptera) with highly specialized egg morphology

The tribe Maxfischeriini, previously placed in Helconinae, is emended to subfamily status based on morphological and biological evidence. Proposed autapomorphies for Maxfischeriinae include: the presence of a pronotal shelf, forewing vein 1a and 2a present, although 1a nebulous, ventral valve of the ovipositor with serrations from tip to base and specialized egg morphology. The novel, pedunculate egg morphology is described for Maxfischeria, representing a new life‐history strategy among Braconidae. Based on egg and ovipositor morphology, we suggest that Maxfischeria is a proovigenic, koinobiont ectoparasitoid. Five new species of Maxfischeria Papp are described with an illustrated key to all species (Maxfischeria ameliaesp.n., Maxfischeria anicsp.n., Maxfischeria briggsisp.n., Maxfischeria folkertsorumsp.n. and Maxfischeria ovumancorasp.n.). In addition to the identification key presented here, all known species of Maxfischeria can be separated using the barcoding region of cytochrome c oxidase subunit I (COI). Based on molecular data, the phylogenetic relationships among the six known species of Maxfischeria are as follows: (M. folkertsorumsp.n. (M. ovumancorasp.n. (M. briggsisp.n. (M. anicsp.n. (M. tricolor + M. ameliaesp.n.))))).

Integrative taxonomy improves understanding of native beneficial fauna: revision of the Nearctic Peristenus pallipes complex (Hymenoptera: Braconidae) and implications for release of exotic biocontrol agents

The Nearctic Peristenus pallipes complex (Hymenoptera: Braconidae) consists of two species groups that are further divided into nine species, separated largely using ecological rather than morphological differences. The species are re‐examined with an integrative approach using morphometric multivariate ratios, molecular (COI and CytB), and ecological data to test the validity of the nine species. The data support only three valid species [P. dayi Goulet, P. mellipes (Cresson) and P. howardi Shaw] rather than nine. New synonymies include: P. braunae Goulet under P. dayi Goulet 2006 syn.n.; P. carcamoi Goulet, P. otaniae Goulet and P. pseudopallipes (Loan) under P. mellipes (Cresson) syn.n., and finally P. broadbenti Goulet 2006 and P. gillespiei Goulet 2006 under P. howardi Shaw 1999 syn.n. In light of these taxonomic revisions, the biology and distributions of the Nearctic P. pallipes complex are updated, resulting in three morphologically variable, widespread, multivoltine species rather than nine largely univoltine species with patchy distributions. The integrative taxonomic approach used here allowed for a more accurate delineation of native fauna and their potential to be competitively displaced by foreign biocontrol agents.

Rapid Viral Symbiogenesis via Changes in Parasitoid Wasp Genome Architecture

Viral genome integration provides a complex route to biological innovation that has rarely but repeatedly occurred in one of the most diverse lineages of organisms on the planet, parasitoid wasps. We describe a novel endogenous virus in braconid wasps derived from pathogenic alphanudiviruses. Limited to a subset of the genus Fopius, this recent acquisition allows an unprecedented opportunity to examine early endogenization events. Massive amounts of virus-like particles (VLPs) are produced in wasp ovaries. Unlike most endogenous viruses of parasitoid wasps, the VLPs do not contain DNA, translating to major differences in parasitism-promoting strategies. Rapid changes include genomic rearrangement, loss of DNA processing proteins, and wasp control of viral gene expression. These events precede the full development of tissue-specific viral gene expression observed in older associations. These data indicate that viral endogenization can rapidly result in functional and evolutionary changes associated with genomic novelty and adaptation in parasitoids.