A New Species and Synonymy of The Neotropical Eucelatoria Townsend and Redescription of Myiodoriops Townsend

The New World tropics represents the most diverse region for tachinid parasitoids (Diptera: Tachinidae), but it also contains the most narrowly defined, and possibly the most confusing, tachinid genera of any biogeographic region. This over-splitting of genera and taxonomic confusion has limited progress toward our understanding the family in this region and much work is needed to revise, redefine, and make sense of the profusion of finely split taxa. In a recent analysis of the Neotropical genus Erythromelana Townsend, two species previously assigned to this genus, Euptilodegeeria obumbrata (Wulp) and Myiodoriops marginalis Townsend were reinstated as monotypic genera. In the present study, we demonstrate that Euptilodegeeria obumbrata (Wulp), previously assigned to three different genera, represents in fact a species of the large New World genus Eucelatoria Townsend, in which females possess a sharp piercer for oviposition. We also show that the species Eucelatoria carinata (Townsend) belongs to the same species group as Eucelatoria obumbrata, which we here define and characterize as the E. obumbrata species group. Additionally, we describe Eucelatoria flava sp. n. as a new species within the E. obumbrata species group. Finally, we redescribe the genus Myiodoriops Townsend and the single species M. marginalis Townsen

Parasitism of Corn Earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), by Tachinid Flies in Cultivated Hemp

In a survey on hemp grown in western Kentucky we found an average of 27.8 CEW larvae per plant. We recorded 45% parasitism of CEW in these fields by two species of tachinid flies, Winthemia rufopicta and Lespesia aletiae. Most parasitized larvae were third to sixth instars at the time of collection. We found up to 22 tachinid eggs per host larva, 89% of which typically bore between 1 and 5 eggs on the thorax. 45.9% of CEW bearing eggs died. The number of tachinid eggs per host was unrelated to host body mass, but both the number of tachinid eggs and caterpillar body mass influenced CEW survival. Larger CEW often survived parasitism and the number of fly eggs was negatively related to survival rate. The emergence of adult flies was positively correlated with the number of eggs, but no influence of the host size was found. High mortality of CEW larvae and the parasitoids developing within them in this system suggests that secondary chemicals (or poor nutrition) of the hemp diet may be negatively affecting host and parasitoid development and influencing their interactions

Diversity of Interactions: A Metric for Studies of Biodiversity

Multitrophic interactions play key roles in the origin and maintenance of species diversity, and the study of these interactions has contributed to important theoretical advances in ecology and evolutionary biology. Nevertheless, most biodiversity inventories focus on static species lists, and prominent theories of diversity still ignore trophic interactions. The lack of a simple interaction metric that is analogous to species richness is one reason why diversity of interactions is not examined as a response or predictor variable in diversity studies. Using plant-herbivore-enemy trophic chains as an example, we develop a simple metric of diversity in which richness, diversity indices (e.g., Simpson\u27s 1/D), and rarefaction diversity are calculated with links as the basic unit rather than species. Interactions include all two-link (herbivore-plant and enemy-herbivore) and three-link (enemy-herbivore-plant) chains found in a study unit. This metric is different from other indices, such as traditional diversity measures, connectivity and interaction diversity in food-web studies, and the diversity of interaction index in behavioral studies, and it is easier to compute. Using this approach to studying diversity provides novel insight into debates about neutrality and correlations between diversity, stability, productivity, and ecosystem services

Continuing Progress towards a Phylogeny of Tachinidae

Readers of this newsletter are likely familiar with our ongoing project to establish a framework phylogeny of world Tachinidae (see articles in The Tachinid Times 26 and 27). This collaborative project, involving myself, Jim O’Hara, Kevin Moulton, Pierfilippo Cerretti, Isaac Winkler and a long list of collaborating tachinidophiles was initiated in 2012 with funding from the U.S. National Science Foundation. Our goal is to produce a robust phylogenetic framework of Tachinidae that can be used to inform tachinid taxonomy, systematics research, and the patterns of tachinid evolution. In previous issues of The Tachinid Times we summarized our progress to date in terms of obtaining taxa (e.g., Cerretti et al. 2013, O’Hara et al. 2014) and some of our preliminary phylogenetic findings (Stireman et al. 2013, Winkler et al. 2014). Here, we provide a brief update on some of our recent progress and associated products

First fossil of an oestroid fly (Diptera: Calyptratae: Oestroidea) and the dating of oestroid divergences

Calyptrate flies include about 22,000 extant species currently classified into Hippoboscoidea (tsetse, louse, and bat flies), the muscoid grade (house flies and relatives) and the Oestroidea (blow flies, bot flies, flesh flies, and relatives). Calyptrates are abundant in nearly all terrestrial ecosystems, often playing key roles as decomposers, parasites, parasitoids, vectors of pathogens, and pollinators. For oestroids, the most diverse group within calyptrates, definitive fossils have been lacking. The first unambiguous fossil of Oestroidea is described based on a specimen discovered in amber from the Dominican Republic. The specimen was identified through digital dissection by CT scans, which provided morphological data for a cladistic analysis of its phylogenetic position among extant oestroids. The few known calyptrate fossils were used as calibration points for a molecular phylogeny (16S, 28S, CAD) to estimate the timing of major diversification events among the Oestroidea. Results indicate that: (a) the fossil belongs to the family Mesembrinellidae, and it is identified and described as Mesembrinella caenozoica sp. nov.; (b) the mesembrinellids form a sister clade to the Australian endemic Ulurumyia macalpinei (Ulurumyiidae) (McAlpine’s fly), which in turn is sister to all remaining oestroids; (c) the most recent common ancestor of extant Calyptratae lived just before the K–Pg boundary (ca. 70 mya); and (d) the radiation of oestroids began in the Eocene (ca. 50 mya), with the origin of the family Mesembrinellidae dated at ca. 40 mya. These results provide new insight into the timing and rate of oestroid diversification and highlight the rapid radiation of some of the most diverse and ecologically important families of flies. ZooBank accession number–urn:lsid:zoobank.org:pub:0DC5170B-1D16-407A-889E-56EED3FE3627.publishedVersio

Remarkable fly (Diptera) diversity in a patch of Costa Rican cloud forest : Why inventory is a vital science

Study of all flies (Diptera) collected for one year from a four-hectare (150 x 266 meter) patch of cloud forest at 1,600 meters above sea level at Zurqui de Moravia, San Jose Province, Costa Rica (hereafter referred to as Zurqui), revealed an astounding 4,332 species. This amounts to more than half the number of named species of flies for all of Central America. Specimens were collected with two Malaise traps running continuously and with a wide array of supplementary collecting methods for three days of each month. All morphospecies from all 73 families recorded were fully curated by technicians before submission to an international team of 59 taxonomic experts for identification. Overall, a Malaise trap on the forest edge captured 1,988 species or 51% of all collected dipteran taxa (other than of Phoridae, subsampled only from this and one other Malaise trap). A Malaise trap in the forest sampled 906 species. Of other sampling methods, the combination of four other Malaise traps and an intercept trap, aerial/hand collecting, 10 emergence traps, and four CDC light traps added the greatest number of species to our inventory. This complement of sampling methods was an effective combination for retrieving substantial numbers of species of Diptera. Comparison of select sampling methods (considering 3,487 species of non-phorid Diptera) provided further details regarding how many species were sampled by various methods. Comparison of species numbers from each of two permanent Malaise traps from Zurqui with those of single Malaise traps at each of Tapanti and Las Alturas, 40 and 180 km distant from Zurqui respectively, suggested significant species turnover. Comparison of the greater number of species collected in all traps from Zurqui did not markedly change the degree of similarity between the three sites, although the actual number of species shared did increase. Comparisons of the total number of named and unnamed species of Diptera from four hectares at Zurqui is equivalent to 51% of all flies named from Central America, greater than all the named fly fauna of Colombia, equivalent to 14% of named Neotropical species and equal to about 2.7% of all named Diptera worldwide. Clearly the number of species of Diptera in tropical regions has been severely underestimated and the actual number may surpass the number of species of Coleoptera. Various published extrapolations from limited data to estimate total numbers of species of larger taxonomic categories (e.g., Hexapoda, Arthropoda, Eukaryota, etc.) are highly questionable, and certainly will remain uncertain until we have more exhaustive surveys of all and diverse taxa (like Diptera) from multiple tropical sites. Morphological characterization of species in inventories provides identifications placed in the context of taxonomy, phylogeny, form, and ecology. DNA barcoding species is a valuable tool to estimate species numbers but used alone fails to provide a broader context for the species identified.Peer reviewe

Tachinid Collecting in Southwest New Mexico and Arizona during the 2007 NADS Field Meeting

The 2007 field meeting of the North American Dipterists Society (NADS) was held August 13–16 in southwestern New Mexico, centered in Silver City (at Western New Mexico University), and the surrounding Gila National Forest. This was the first NADS meeting that I have been able to attend, and I think I can speak for all in saying it was enjoyable, productive, and interesting; an overall success. A more detailed account and evaluation of this meeting is available in the 2007 Fly Times article (O’Hara 2007)

Phylogenetic Reconstruction of Exoristinae Using Molecular Data: a Bayesian re-analysis

A few years ago I published the results of a phylogenetic analysis of New World Exoristinae based on molecular data from two genes, 28S rDNA and Elongation Factor 1-alpha (Stireman 2002). In that study I employed parsimony, neighbor joining, and maximum likelihood inference methods to generate phylogenetic reconstructions, and explored a variety of weighting schemes and combinations of the sequence data (i.e. each gene separately and both together). The results of these analyses generally supported recent taxonomic hypotheses (e.g., Herting 1984; Wood 1987; O’Hara and Wood 2004). For example, Tachinidae and Exoristinae were reconstructed as monophyletic in most analyses, as were the Exoristini, Winthemiini, and Blondeliini. However, there were also some ambiguous and unexpected results. First, representative taxa of Tachininae and Phasiinae (used as outgroups) failed to support monophyly for either of these subfamilies. Also, species of the genera Masiphya (Masiphyini), Ceracia (Tachininae), and Phyllophilopsis (Blondeliini) tended to form a clade that varied widely in position between reconstructions. Perhaps most interesting, all reconstructions indicated a paraphyletic or polyphyletic Goniini. Finally, and most disturbing, was the fact that my representative of Drino (D. incompta) was often reconstructed near the base of Exoristinae joining taxa from other subfamilies (at least in analyses of EF1 alpha) even though all morphological considerations would place this taxon with other “Eryciini”

Preliminary Notes on Tachinidae Reared from Lepidoptera in the Ecuadorian Andes

Current estimates of the species richness of Tachinidae among geographical provinces suggest that the Neotropical Region harbors the largest number of species and represents a geographic epicenter of tachinid diversification (O’Hara 2006). The Neotropics boasts an impressive fauna consisting of 2864 described species belonging to 822 genera at the time of the Neotropical catalog (Guimarães 1971), making it almost twice as species rich as any other geographic realm (O’Hara 2006; Stireman et al. 2006). This diversity is most apparent at middle elevations (1000– 2000m) along the mountain chains of tropical Central and South America, where tachinids are an abundant and conspicuous component of the diurnal insect fauna. Despite this large number of described species, it is generally thought that only a fraction of Neotropical Tachinidae have been described, and for most of those that have been described, nothing is known about their life history, host associations, or behavior (Guimarães 1977). Here, I provide a preliminary list of the genera and numbers of species that have been reared from a research program focused on rearing Lepidoptera in the Ecuadorian Andes. I also provide host–family affiliations for most taxa as well as notes concerning the species reared, their characteristics, and/or their host associations. A more complete analysis of species diversity patterns and host associations will be published in a forthcoming special issue of the Journal of Research on the Lepidoptera

The Evolution of Generalization? Parasitoid Flies and the Perils of Inferring Host Range Evolution from Phylogenies

It is widely assumed that high resource specificity predisposes lineages toward greater likelihood of extinction and lower likelihood of diversification than more generalized lineages. This suggests that host range evolution in parasitic organisms should proceed from generalist to specialist, and specialist lineages should be found at the ‘tips’ of phylogenies. To test these hypotheses, parsimony and maximum likelihood methods were used to reconstruct the evolution of host range on a phylogeny of parasitoid flies in the family Tachinidae. In contrast to predictions, most reconstructions indicated that generalists were repeatedly derived from specialist lineages and tended to occupy terminal branches of the phylogeny. These results are critically examined with respect to hypotheses concerning the evolution of specialization, the inherent difficulties in inferring host ranges, our knowledge of tachinid-host associations, and the methodological problems associated with ancestral character state reconstruction. Both parsimony and likelihood reconstructions are shown to provide misleading results and it is argued that independent evidence, in addition to phylogenetic trees, is needed to inform models of the evolution of host range and the evolutionary consequences of specialization