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1.
Elife ; 122024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38662411

RESUMEN

Declines in biodiversity generated by anthropogenic stressors at both species and population levels can alter emergent processes instrumental to ecosystem function and resilience. As such, understanding the role of biodiversity in ecosystem function and its response to climate perturbation is increasingly important, especially in tropical systems where responses to changes in biodiversity are less predictable and more challenging to assess experimentally. Using large-scale transplant experiments conducted at five neotropical sites, we documented the impacts of changes in intraspecific and interspecific plant richness in the genus Piper on insect herbivory, insect richness, and ecosystem resilience to perturbations in water availability. We found that reductions of both intraspecific and interspecific Piper diversity had measurable and site-specific effects on herbivory, herbivorous insect richness, and plant mortality. The responses of these ecosystem-relevant processes to reduced intraspecific Piper richness were often similar in magnitude to the effects of reduced interspecific richness. Increased water availability reduced herbivory by 4.2% overall, and the response of herbivorous insect richness and herbivory to water availability were altered by both intra- and interspecific richness in a site-dependent manner. Our results underscore the role of intraspecific and interspecific richness as foundations of ecosystem function and the importance of community and location-specific contingencies in controlling function in complex tropical systems.


Asunto(s)
Biodiversidad , Ecosistema , Herbivoria , Insectos , Clima Tropical , Animales , Insectos/fisiología , Piper/fisiología
2.
PLoS One ; 18(9): e0285855, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37725599

RESUMEN

Phylogenetic relationships within the oestroid subclades Rhinophorinae (Calliphoridae) and Polleniidae were reconstructed for the first time, applying a Sanger sequencing approach using the two protein-coding nuclear markers CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase; 1794 bp) and MCS (molybdenum cofactor sulfurase; 2078 bp). Three genera of Polleniidae and nineteen genera of Rhinophorinae were analyzed together with a selection of taxa representing the major lineages of Oestroidea (non-rhinophorine Calliphoridae, Oestridae, Sarcophagidae, Tachinidae). The selected markers provide good resolution and moderate to strong support of the distal branches, but weak support for several deeper nodes. Polleniidae (cluster flies) emerge as monophyletic and their sister-group relationship to Tachinidae is confirmed. Morinia Robineau-Desvoidy as currently circumscribed emerges as paraphyletic with regard to Melanodexia Williston, and Pollenia Robineau-Desvoidy is the sister taxon of the Morinia-Melanodexia clade. We propose a classification with two subfamilies, Moriniinae Townsend (including Morinia, Melanodexia, and Alvamaja Rognes), and Polleniinae Brauer & Bergenstamm (including Pollenia, Dexopollenia Townsend, and Xanthotryxus Aldrich). Anthracomyza Malloch and Nesodexia Villeneuve are considered as Oestroidea incertae sedis pending further study. Rhinophorinae (woodlouse flies) emerge as monophyletic and sister to a clade composed of (Ameniinae + (Ameniinae + Phumosiinae)), and a tribal classification is proposed with the subfamily divided into Rhinophorini Robineau-Desvoidy, 1863 and Phytonini Robineau-Desvoidy, 1863 (the Stevenia-group and the Phyto-group of authors, respectively). Oxytachina Brauer & Bergenstamm, 1891, stat. rev. is resurrected to contain nine Afrotropical rhinophorine species currently assigned to genus Rhinomorinia Brauer & Bergenstamm, 1891: Oxytachina approximata (Crosskey, 1977) comb. nov., O. atra (Bischof, 1904) comb. nov., O. bisetosa (Crosskey, 1977) comb. nov., O. capensis (Brauer & Bergenstamm, 1893) comb. nov., O. scutellata (Crosskey, 1977) comb. nov., O. setitibia (Crosskey, 1977) comb. nov., O. verticalis (Crosskey, 1977) comb. nov., O. vittata Brauer & Bergenstamm, 1891, and O. xanthocephala (Bezzi, 1908) comb. nov.


Asunto(s)
Aspartato Carbamoiltransferasa , Brassicaceae , Dípteros , Xylariales , Animales , Dípteros/genética , Calliphoridae , Filogenia
3.
Insects ; 13(6)2022 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-35735857

RESUMEN

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.

4.
Mol Ecol ; 28(18): 4317-4334, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31483075

RESUMEN

Population divergence can occur due to mechanisms associated with geographic isolation and/or due to selection associated with different ecological niches. Much of the evidence for selection-driven speciation has come from studies of specialist insect herbivores that use different host plant species; however, the influence of host plant use on population divergence of generalist herbivores remains poorly understood. We tested how diet breadth, host plant species and geographic distance influence population divergence of the fall webworm (Hyphantria cunea; FW). FW is a broadly distributed, extreme generalist herbivore consisting of two morphotypes that have been argued to represent two different species: black-headed and red-headed. We characterized the differentiation of FW populations at two geographic scales. We first analysed the influence of host plant and geographic distance on genetic divergence across a broad continental scale for both colour types. We further analysed the influence of host plant, diet breadth and geographic distance on divergence at a finer geographic scale focusing on red-headed FW in Colorado. We found clear genetic and morphological distinction between red- and black-headed FW, and Colorado FW formed a genetic cluster distinct from other locations. Although both geographic distance and host plant use were correlated with genetic distance, geographic distance accounted for up to 3× more variation in genetic distance than did host plant use. As a rare study investigating the genetic structure of a widespread generalist herbivore over a broad geographic range (up to 3,000 km), our study supports a strong role for geographic isolation in divergence in this system.


Asunto(s)
Genética de Población , Geografía , Herbivoria/genética , Interacciones Huésped-Parásitos/genética , Mariposas Nocturnas/genética , Plantas/parasitología , Animales , Dieta , Mariposas Nocturnas/anatomía & histología , Filogenia , Estados Unidos
5.
Ecology ; 100(12): e02861, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31380568

RESUMEN

Habitat destruction is the single greatest anthropogenic threat to biodiversity. Decades of research on this issue have led to the accumulation of hundreds of data sets comparing species assemblages in larger, intact, habitats to smaller, more fragmented, habitats. Despite this, little synthesis or consensus has been achieved, primarily because of non-standardized sampling methodology and analyses of notoriously scale-dependent response variables (i.e., species richness). To be able to compare and contrast the results of habitat fragmentation on species' assemblages, it is necessary to have the underlying data on species abundances and sampling intensity, so that standardization can be achieved. To accomplish this, we systematically searched the literature for studies where abundances of species in assemblages (of any taxa) were sampled from many habitat patches that varied in size. From these, we extracted data from several studies, and contacted authors of studies where appropriate data were collected but not published, giving us 117 studies that compared species assemblages among habitat fragments that varied in area. Less than one-half (41) of studies came from tropical forests of Central and South America, but there were many studies from temperate forests and grasslands from all continents except Antarctica. Fifty-four of the studies were on invertebrates (mostly insects), but there were several studies on plants (15), birds (16), mammals (19), and reptiles and amphibians (13). We also collected qualitative information on the length of time since fragmentation. With data on total and relative abundances (and identities) of species, sampling effort, and affiliated meta-data about the study sites, these data can be used to more definitively test hypotheses about the role of habitat fragmentation in altering patterns of biodiversity. There are no copyright restrictions. Please cite this data paper and the associated Dryad data set if the data are used in publications.

6.
Mol Phylogenet Evol ; 140: 106602, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31449853

RESUMEN

Gall midges (Cecidomyiidae) constitute one of the largest and most diverse families of Diptera, with close to 6600 described species and thousands of undescribed species worldwide. The family is divided into six subfamilies, the five basal ones comprising only fungivorous taxa, whereas the largest, youngest and most diverse subfamily Cecidomyiinae includes fungivorous as well as herbivorous and predatory species. The currently accepted classification of the Cecidomyiinae is morphology-based, and the few phylogenetic inferences that have previously been suggested for it were based on fragmentary or limited datasets. In a first comprehensive phylogenetic analysis of the Cecidomyiinae we sampled 142 species representing 88 genera of 13 tribes from all feeding guilds and zoogeographic regions in order to test the validity of the systematic division of the subfamily and gain insight into patterns of diversification and the evolution of feeding modes. We used sequences from five mitochondrial and nuclear genes to reconstruct maximum likelihood and Bayesian, time-calibrated phylogenies and conducted ancestral state reconstruction of feeding modes. Our results corroborate to a great extent the morphology-based classification of the Cecidomyiinae, with strong support for all supertribes and tribes, all were apparently established in the Upper Cretaceous concordant with the major radiation of angiosperms. We infer that transitions from fungus-feeding to plant-feeding occurred only once or twice in the evolution of the subfamily and that predation evolved only once, contrary to previous hypotheses. All herbivorous clades in the subfamily are very species rich and have diversified at a significantly greater rate than expected, but we found no support for the assertion that herbivorous clades associated with symbiotic fungi in their galls diversify faster than clades that do not have such associations. Currently available data also do not support the hypothesis that symbiotic clades have broader host ranges than non-symbiotic clades.


Asunto(s)
Biodiversidad , Dípteros/clasificación , Conducta Alimentaria , Filogenia , Animales , Teorema de Bayes , Calibración , Dípteros/genética , Funciones de Verosimilitud , Mitocondrias/genética , Conducta Predatoria
7.
Mol Phylogenet Evol ; 139: 106358, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-30584917

RESUMEN

We reconstructed phylogenetic relationships within the diverse parasitoid fly family Tachinidae using four nuclear loci (7800 bp) and including an exceptionally large sample of more than 500 taxa from around the world. The position of the earthworm-parasitizing Polleniinae (Calliphoridae s.l.) as sister to Tachinidae is strongly supported. Our analyses recovered each of the four tachinid subfamilies and most recognized tribes, with some important exceptions in the Dexiinae and Tachininae. Most notably, the tachinine tribes Macquartiini and Myiophasiini form a clade sister to all other Tachinidae, and a clade of Palpostomatini is reconstructed as sister to Dexiinae + Phasiinae. Although most nodes are well-supported, relationships within several lineages that appear to have undergone rapid episodes of diversification (basal Dexiinae and Tachininae, Blondeliini) were poorly resolved. Reconstructions of host use evolution are equivocal, but generally support the hypothesis that the ancestral host of tachinids was a beetle and that subsequent host shifts to caterpillars may coincide with accelerated diversification. Evolutionary reconstructions of reproductive strategy using alternative methods were incongruent, however it is most likely that ancestral tachinids possessed unincubated, thick shelled eggs from which incubated eggs evolved repeatedly, potentially expanding available host niches. These results provide a broad foundation for understanding the phylogeny and evolution of this important family of parasitoid insects. We hope it will serve as a framework to be used in concert with morphology and other sources of evidence to revise the higher taxonomic classification of Tachinidae and further explore their evolutionary history and diversification.


Asunto(s)
Dípteros/clasificación , Dípteros/genética , Evolución Molecular , Filogenia , Animales , Biodiversidad , Interacciones Huésped-Parásitos
8.
Curr Opin Insect Sci ; 29: 117-125, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30551817

RESUMEN

A multi-trophic perspective improves understanding of the ecological and evolutionary consequences of rapid environmental change on insect herbivores. Loss of specialized enemies due to human impacts is predicted to dramatically reduce the number of tritrophic niches of herbivores compared to a bitrophic niche perspective. Habitat fragmentation and climate change promote the loss of both specialist enemies and herbivores, favoring ecological generalism across trophic levels. Species invasion can fundamentally alter trophic interactions toward various outcomes and contributes to ecological homogenization. Adaptive evolution on ecological timescales is expected to dampen tritrophic instabilities and diversify niches, yet its ability to compensate for tritrophic niche losses in the short term is unclear.


Asunto(s)
Ecosistema , Calentamiento Global , Herbivoria , Insectos/fisiología , Animales , Ambiente , Cadena Alimentaria
9.
Am Nat ; 192(1): E21-E36, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29897808

RESUMEN

Most studies of adaptive radiation in animals focus on resource competition as the primary driver of trait divergence. The roles of other ecological interactions in shaping divergent phenotypes during such radiations have received less attention. We evaluate natural enemies as primary agents of diversifying selection on the phenotypes of an actively diverging lineage of gall midges on tall goldenrod. In this system, the gall of the midge consists of a biotrophic fungal symbiont that develops on host-plant leaves and forms distinctly variable protective carapaces over midge larvae. Through field studies, we show that fungal gall morphology, which is induced by midges (i.e., it is an extended phenotype), is under directional and diversifying selection by parasitoid enemies. Overall, natural enemies disruptively select for either small or large galls, mainly along the axis of gall thickness. These results imply that predators are driving the evolution of phenotypic diversity in symbiotic defense traits in this system and that divergence in defensive morphology may provide ecological opportunities that help to fuel the adaptive radiation of this genus of midges on goldenrods. This enemy-driven phenotypic divergence in a diversifying lineage illustrates the potential importance of consumer-resource and symbiotic species interactions in adaptive radiation.


Asunto(s)
Ascomicetos/fisiología , Dípteros/genética , Tumores de Planta , Conducta Predatoria , Selección Genética , Animales , Evolución Biológica , Dípteros/microbiología , Larva/microbiología , Solidago/genética , Solidago/microbiología , Solidago/parasitología , Avispas/fisiología
10.
Zootaxa ; 4402(1): 53-90, 2018 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-29690278

RESUMEN

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 Zurquí de Moravia, San José Province, Costa Rica (hereafter referred to as Zurquí), 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 Zurquí with those of single Malaise traps at each of Tapantí and Las Alturas, 40 and 180 km distant from Zurquí respectively, suggested significant species turnover. Comparison of the greater number of species collected in all traps from Zurquí 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 Zurquí 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.


Asunto(s)
Dípteros , Animales , Biodiversidad , América Central , Colombia , Costa Rica , Bosques
11.
PLoS One ; 12(8): e0182101, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28832610

RESUMEN

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.


Asunto(s)
Dípteros , Fósiles , Animales , Dípteros/clasificación , Dípteros/genética , Filogenia
12.
Curr Opin Insect Sci ; 14: 87-93, 2016 04.
Artículo en Inglés | MEDLINE | ID: mdl-27436652

RESUMEN

The study of parasitoid communities is an active and dynamic field. Most studies, however, are focused primarily on parasitic wasps, despite the thousands of other insect parasitoids distributed across many lineages. Although questions in parasitoid community ecology are much the same for different groups, answers to these questions may not be due to differing biological traits. The ecology of non-hymenopteran ('NH') parasitoid communities is poorly known, but recent work indicates that habitat and host traits have strong impacts on the size and composition of these parasitoid assemblages. Recent food-web analyses indicate that host ranges vary widely within and among taxa and associations are shaped by host ecology and defenses. Evidence is also accumulating for strong 'bottom-up' and 'top-down' multi-trophic interactions between NH-parasitoids and nonadjacent trophic levels, as well as trait-mediated indirect effects on communities. Recent technical and conceptual advances in characterizing and comparing food webs, consideration of phylogenetic history, and increasing anthropogenic impacts provide many new and stimulating areas of research on parasitoid communities.


Asunto(s)
Ecosistema , Parásitos/fisiología , Animales , Ecología , Cadena Alimentaria , Filogenia
13.
Mol Phylogenet Evol ; 88: 38-54, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25841383

RESUMEN

Molecular phylogenetic studies at all taxonomic levels often infer rapid radiation events based on short, poorly resolved internodes. While such rapid episodes of diversification are an important and widespread evolutionary phenomenon, much of this poor phylogenetic resolution may be attributed to the continuing widespread use of "traditional" markers (mitochondrial, ribosomal, and some nuclear protein-coding genes) that are often poorly suited to resolve difficult, higher-level phylogenetic problems. Here we reconstruct phylogenetic relationships among a representative set of taxa of the parasitoid fly family Tachinidae and related outgroups of the superfamily Oestroidea. The Tachinidae are one of the most species rich, yet evolutionarily recent families of Diptera, providing an ideal case study for examining the differential performance of loci in resolving phylogenetic relationships and the benefits of adding more loci to phylogenetic analyses. We assess the phylogenetic utility of nine genes including both traditional genes (e.g., CO1 mtDNA, 28S rDNA) and nuclear protein-coding genes newly developed for phylogenetic analysis. Our phylogenetic findings, based on a limited set of taxa, include: a close relationship between Tachinidae and the calliphorid subfamily Polleninae, monophyly of Tachinidae and the subfamilies Exoristinae and Dexiinae, subfamily groupings of Dexiinae+Phasiinae and Tachininae+Exoristinae, and robust phylogenetic placement of the somewhat enigmatic genera Strongygaster, Euthera, and Ceracia. In contrast to poor resolution and phylogenetic incongruence of "traditional genes," we find that a more selective set of highly informative genes is able to more precisely identify regions of the phylogeny that experienced rapid radiation of lineages, while more accurately depicting their phylogenetic context. Although much expanded taxon sampling is necessary to effectively assess the monophyly of and relationships among major tachinid lineages and their relatives, we show that a small number of well-chosen nuclear protein-coding genes can successfully resolve even difficult phylogenetic problems.


Asunto(s)
Dípteros/clasificación , Filogenia , Animales , Dípteros/genética , Genes de Insecto , Proteínas de Insectos/genética , Proteínas Mitocondriales/genética
14.
Proc Natl Acad Sci U S A ; 112(2): 442-7, 2015 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-25548168

RESUMEN

Understanding variation in resource specialization is important for progress on issues that include coevolution, community assembly, ecosystem processes, and the latitudinal gradient of species richness. Herbivorous insects are useful models for studying resource specialization, and the interaction between plants and herbivorous insects is one of the most common and consequential ecological associations on the planet. However, uncertainty persists regarding fundamental features of herbivore diet breadth, including its relationship to latitude and plant species richness. Here, we use a global dataset to investigate host range for over 7,500 insect herbivore species covering a wide taxonomic breadth and interacting with more than 2,000 species of plants in 165 families. We ask whether relatively specialized and generalized herbivores represent a dichotomy rather than a continuum from few to many host families and species attacked and whether diet breadth changes with increasing plant species richness toward the tropics. Across geographic regions and taxonomic subsets of the data, we find that the distribution of diet breadth is fit well by a discrete, truncated Pareto power law characterized by the predominance of specialized herbivores and a long, thin tail of more generalized species. Both the taxonomic and phylogenetic distributions of diet breadth shift globally with latitude, consistent with a higher frequency of specialized insects in tropical regions. We also find that more diverse lineages of plants support assemblages of relatively more specialized herbivores and that the global distribution of plant diversity contributes to but does not fully explain the latitudinal gradient in insect herbivore specialization.


Asunto(s)
Dieta , Herbivoria/fisiología , Insectos/fisiología , Animales , Biodiversidad , Ecosistema , Especificidad del Huésped , Insectos/clasificación , Lepidópteros/clasificación , Lepidópteros/fisiología , Modelos Biológicos , Filogenia
15.
Oecologia ; 176(1): 207-24, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25015121

RESUMEN

Habitat fragmentation and invasive species are two of the most prominent threats to terrestrial ecosystems. Few studies have examined how these factors interact to influence the diversity of natural communities, particularly primary consumers. Here, we examined the effects of forest fragmentation and invasion of exotic honeysuckle (Lonicera maackii, Caprifoliaceae) on the abundance and diversity of the dominant forest herbivores: woody plant-feeding Lepidoptera. We systematically surveyed understory caterpillars along transects in 19 forest fragments over multiple years in southwestern Ohio and evaluated how fragment area, isolation, tree diversity, invasion by honeysuckle and interactions among these factors influence species richness, diversity and abundance. We found strong seasonal variation in caterpillar communities, which responded differently to fragmentation and invasion. Abundance and richness increased with fragment area, but these effects were mitigated by high levels of honeysuckle, tree diversity, landscape forest cover, and large recent changes in area. Honeysuckle infestation was generally associated with decreased caterpillar abundance and diversity, but these effects were strongly dependent on other fragment traits. Effects of honeysuckle on abundance were moderated when fragment area, landscape forest cover and tree diversity were high. In contrast, negative effects of honeysuckle invasion on caterpillar diversity were most pronounced in fragments with high tree diversity and large recent increases in area. Our results illustrate the complex interdependencies of habitat fragmentation, plant diversity and plant invasion in their effects on primary consumers and emphasize the need to consider these processes in concert to understand the consequences of anthropogenic habitat change for biodiversity.


Asunto(s)
Biodiversidad , Ecosistema , Especies Introducidas , Lepidópteros/fisiología , Lonicera/fisiología , Árboles/fisiología , Animales , Larva/fisiología , Modelos Biológicos , Ohio , Dinámica Poblacional
16.
New Phytol ; 202(4): 1357-1370, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24611577

RESUMEN

Understanding the evolutionary reasons for patterns of chemical defense in plants is an ongoing theoretical and empirical challenge. The goal is to develop a model that can reliably predict how defenses are distributed within the plant over space and time. This is difficult given that evolutionary, ecological, and physiological processes and tradeoffs can operate over different spatial and temporal scales. We evaluated the major predictions of two leading defense theories, the growth-differentiation balance hypothesis (GDBH) and optimal defense theory (ODT). To achieve this, enemies, fitness components, terpenoids, and protease inhibitors were measured in Solidago altissima and used to construct conventional univariate and structural equation models (SEMs). Leaf-tissue value indices extracted from an SEM revealed a strong correlation between tissue value and terpenoid defense that supports ODT. A tradeoff between serine protease inhibition and growth as well as an indirect tradeoff between growth and terpenoids manifested through galling insects supported the GDBH. Interestingly, there was a strong direct effect of terpenoids on rhizome mass, suggesting service to both storage and defense. The results support established theories but unknown genotypic traits explained much of the variation in defense, confirming the need to integrate emerging theories such as pollination constraints, defense syndromes, tolerance, mutualisms, and facilitation.


Asunto(s)
Modelos Estadísticos , Enfermedades de las Plantas/inmunología , Inmunidad de la Planta , Solidago/inmunología , Terpenos/aislamiento & purificación , Animales , Biomasa , Herbivoria , Insectos/fisiología , Fenotipo , Hojas de la Planta/química , Hojas de la Planta/inmunología , Hojas de la Planta/fisiología , Inhibidores de Proteasas/metabolismo , Rizoma , Solidago/química , Solidago/fisiología
17.
Zookeys ; (464): 63-97, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25589870

RESUMEN

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, Euptilodegeeriaobumbrata (Wulp) and Myiodoriopsmarginalis Townsend were reinstated as monotypic genera. In the present study, we demonstrate that Euptilodegeeriaobumbrata (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 Eucelatoriacarinata (Townsend) belongs to the same species group as Eucelatoriaobumbrata, which we here define and characterize as the Eucelatoriaobumbrata species group. Additionally, we describe Eucelatoriaflava sp. n. as a new species within the Eucelatoriaobumbrata species group. Finally, we redescribe the genus Myiodoriops Townsend and the single species Myiodoriopsmarginalis Townsend.

18.
Mol Phylogenet Evol ; 68(2): 221-8, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23542649

RESUMEN

Carotenoids are conjugated isoprenoid molecules with many important physiological functions in organisms, including roles in photosynthesis, oxidative stress reduction, vision, diapause, photoperiodism, and immunity. Until recently, it was believed that only plants, microorganisms, and fungi were capable of synthesizing carotenoids and that animals acquired them from their diet, but recent studies have demonstrated that two arthropods (pea aphid and spider mite) possess a pair of genes homologous to those required for the first step of carotenoid biosynthesis. Absent in all other known animal genomes, these genes appear to have been acquired by aphids and spider mites in one or several lateral gene transfer events from a fungal donor. We report the third case of fungal carotenoid biosynthesis gene homologs in an arthropod: flies from the family Cecidomyiidae, commonly known as gall midges. Using phylogenetic analyses we show that it is unlikely that lycopene cyclase/phytoene synthase and phytoene desaturase homologs were transferred singly to an ancient arthropod ancestor; instead we propose that genes were transferred independently from related fungal donors after divergence of the major arthropod lineages. We also examine variation in intron placement and copy number of the carotenoid genes that may underlie function in the midges. This trans-kingdom transfer of carotenoid genes may represent a key innovation, underlying the evolution of phytophagy and plant-galling in gall midges and facilitating their extensive diversification across plant lineages.


Asunto(s)
Carotenoides/biosíntesis , Dípteros/genética , Transferencia de Gen Horizontal , Proteínas de Insectos/genética , Oxidorreductasas/genética , Animales , Carotenoides/genética , Dípteros/enzimología , Evolución Molecular , Dosificación de Gen , Genes Fúngicos , Geranilgeranil-Difosfato Geranilgeraniltransferasa/genética , Liasas Intramoleculares/genética , Funciones de Verosimilitud , Anotación de Secuencia Molecular , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN
19.
Zootaxa ; 3621: 1-82, 2013 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-25136728

RESUMEN

The Neotropics harbor an enormous diversity of tachinid flies (Diptera: Tachinidae), yet the fauna remains poorly understood. This is especially true of the tribe Blondeliini, which is particularly diverse in this region and in great need of taxonomic attention. Here, the Neotropical blondeliine genus Erythromelana Townsend is revised. This genus is widely distributed from southern Mexico to northern Argentina, with the Andes being a hotspot of diversity. Known hosts belong to the genus Eois Hübner (Lepidoptera: Geometridae). This revision includes the redescription of three previously described species and the description of 11 new species based on characteristics of adults and immatures. The new species are E. arciforceps sp. nov., E. catarina sp. nov., E. convexiforceps sp. nov., E. cryptica sp. nov., E. curvifrons sp. nov., E. distincta sp. nov., E. ecuadoriana sp. nov., E. eois sp. nov., E. leptoforceps sp. nov., E. napensis sp. nov., and E. woodi sp. nov. A morphological database of 62 characters was constructed to assess morphological variation within and among species and species groups using Principal Components Analysis. Means and medians for these morphological traits were calculated to infer phylogenetic relationships using parsimony. Additionally, a maximum likelihood phylogenetic analysis was performed using COI mtDNA sequences for a subset of eight species. Nominal species E. obscurifrons (Wulp) is treated as a nomen dubium within Erythromelana. Two species previously assigned to Erythromelana appear to represent distinct genera with unclear relationships to this genus and are reinstated as monotypic genera: Myiodoriops marginalis Townsend and Euptilodegeeria obumbrata (Wulp), revived status. Biological and phylogenetic data are used to infer modes of diversification within Erythromelana.


Asunto(s)
Biodiversidad , Dípteros/clasificación , Dípteros/fisiología , Lepidópteros/parasitología , Filogenia , Distribución Animal , Animales , Dípteros/anatomía & histología , Dípteros/genética , Complejo IV de Transporte de Electrones/genética , Complejo IV de Transporte de Electrones/metabolismo , Femenino , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Masculino , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Pupa/anatomía & histología , Pupa/clasificación , Análisis de Secuencia de ADN , Especificidad de la Especie
20.
Mol Phylogenet Evol ; 54(1): 194-210, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19765662

RESUMEN

Gall-forming insects provide ideal systems to analyze the evolution of host-parasite interactions and understand the ecological interactions that contribute to evolutionary diversification. Flies in the family Cecidomyiidae represent the largest radiation of gall-forming insects and are characterized by complex trophic interactions with plants, fungal symbionts, and predators. We analyzed the phylogenetic history and evolutionary associations of the North American cecidomyiid genus Asteromyia, which is engaged in a complex and perhaps co-evolving community of interactions with host-plants, fungi, and parasitoids. Mitochondrial gene trees generally support current classifications, but reveal extensive cryptic diversity within the eight named species. Asteromyia likely radiated after their associated host-plants in the Astereae, but species groups exhibit strong associations with specific lineages of Astereae. Evolutionary associations with fungal mutualists are dynamic, however, and suggest rapid and perhaps coordinated changes across trophic levels.


Asunto(s)
Dípteros/genética , Evolución Molecular , Especiación Genética , Filogenia , Plantas/parasitología , Animales , ADN Mitocondrial/genética , Dípteros/clasificación , Ecología , Hongos/fisiología , Genes de Insecto , Interacciones Huésped-Parásitos/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Simbiosis
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