Species richness and abundance of defoliating Lepidoptera associated with Eucalyptus grandis in Brazil and their response to plant age

The present paper documents patterns of species richness and abundance in Lepidoptera associated with a Eucalyptus grandis plantation, and how these patterns relate to plant age. The large number of species collected (1385), the lack of dominant species and the absence of pest outbreaks during the survey may be related to the high level of plant diversity of the native forest reserves in the area. There was no clear pattern of seasonal variation in species richness, but there were seasonal fluctuations in abundance, with minor defoliator species prevailing in October at the start of the rainy season. Species richness and abundance of Lepidoptera were positively correlated, with both variables decreasing in older plantations. However, the greatest numbers of major outbreak species and minor eucalypt defoliators were observed in plants after the mid‐point (6 years old) of their cutting cycle (7–10 years). This may be because of a larger amount of better‐quality plant leaves after this mid‐point or the reduction in silvicultural management interventions at this period of the Eucalyptus cutting cycle. The abundance of the main outbreak species observed in the survey, Stenalcidia grosica Schaus (Geometridae), was negatively correlated with plant age. Nonetheless, the effect was weak (r = – 0.21, P = 0.03) and we were not able to find further significant correlations between plant age and abundance of the other most frequent and constant species that were collected.     

Detection of a Bacterium Associated with a Leaf Spot Disease of Maize in Brazil

A leaf spot disease of maize occurring in Brazil in the 1980s was described as being caused by the ascomycete Phaeosphaeria maydis (P. Henn) Rane. Payak and Renfro (imperfect form Phyllosticta sp.). Disease symptoms were dark-green water-soaked spots that later became necrotic lesions. There are no reports at present in the literature of re-infection by the fungus under controlled conditions, casting doubt on the true identity of the pathogen. In this study, cytological analyses of lesions at the initial stages did not detect the presence of fungal structures. Bacterial colonies with yellow pigmentation were isolated from the lesions, which reacted positively in hypersensitivity tests in tobacco plants. Maize plants were inoculated with the isolated bacteria. After 72 h incubation in a dew chamber, plants were transferred to a greenhouse, where they remained until evaluation. Typical symptoms of the disease were observed 5–7 days after inoculation of plants, only on treatments inoculated with the bacteria. The bacterium was re-isolated, which suggests its involvement in the initial phases of disease. The bacterium was identified as Pantoea ananas (synonym Erwinia ananas ).     

Genetic Diversity of Badnaviruses Associated with Bougainvillea in Brazil

The genus Bougainvillea is native to South America and is cultivated worldwide for ornamental purposes. To investigate the diversity of bougainvillea badnavirus populations, plants with various types of symptoms from different regions of Brazil were collected and subjected to DNA extraction, PCR, cloning and sequencing. Sequence analysis revealed that clones from the Brasília (DF) isolate showed maximum identity of 71.7%. No genetic diversity was observed in partial RT/RNase H sequences of Badnavirus isolates derived from the bougainvillea clones grown in São Paulo (SP) state, which shared a monophyletic group with 100% bootstrap in the tree topology reconstructed by maximum likelihood. One clade consistently supported by 100% bootstrap formed by clones of the samples from Minas Gerais (MG) and Ceará (CE) states and Taiwan was also observed. Furthermore, DF, CE and MG isolates formed a monophyletic group with the Delhi isolate, which may represent a new Badnavirus species that infects bougainvillea. Two Brazilian isolates and one from Taiwan appeared to have recombination sites in the RT and RNase H conserved region of BCVBV. These results demonstrate the existence of at least three probably new bougainvillea badnavirus species or strains, which may be spread, as this ornamental is vegetatively propagated.     

Bee Species Diversity Enhances Productivity and Stability in a Perennial Crop

Wild bees provide important pollination services to agroecoystems, but the mechanisms which underlie their contribution to ecosystem functioning—and, therefore, their importance in maintaining and enhancing these services—remain unclear. We evaluated several mechanisms through which wild bees contribute to crop productivity, the stability of pollinator visitation, and the efficiency of individual pollinators in a highly bee-pollination dependent plant, highbush blueberry. We surveyed the bee community (through transect sampling and pan trapping) and measured pollination of both open- and singly-visited flowers. We found that the abundance of managed honey bees, Apis mellifera, and wild-bee richness were equally important in describing resulting open pollination. Wild-bee richness was a better predictor of pollination than wild-bee abundance. We also found evidence suggesting pollinator visitation (and subsequent pollination) are stabilized through the differential response of bee taxa to weather (i.e., response diversity). Variation in the individual visit efficiency of A. mellifera and the southeastern blueberry bee, Habropoda laboriosa, a wild specialist, was not associated with changes in the pollinator community. Our findings add to a growing literature that diverse pollinator communities provide more stable and productive ecosystem services.     

Fusarium Species Associated with Mango Malformation in Peninsular Malaysia

Mango malformation has become the most important global disease on mango. Fusarium species previously associated with this disease include F. mangiferae, F. mexicanum, F. sterilihyphosum, F. proliferatum, F. subglutinans and F. tupiense. A few strains of F. proliferatum have been reported from Malaysia, but in this study, we report the results of more extensive sampling. The recovered strains were evaluated with morphology, mating tester strain cross‐fertility, amplified fragment length polymorphisms (AFLPs), and partial DNA sequences of the genes encoding translation elongation factor 1‐α (tef‐1α) and β‐tubulin (tub‐2). Amongst the 43 strains evaluated, three species were identified – F. proliferatum, F. mangiferae and F. subglutinans – with F. proliferatum being the most frequent (69%). None of the Fusarium species that appear to originate in the Americas were recovered in Malaysia, which suggests special measures may be warranted to keep these species from entering the country.     

The Role of Exotic Species in Traditional Pharmacopeias of the Cerrado: a Case Study in Southeast Brazil

The “diversification hypothesis” proposes that exotic species are incorporated into plant pharmacopeias to broaden the range of treatments and meet therapeutic demands unattended by native species. The “versatility hypothesis” suggests that the wider range of uses of exotic species explains their selection in traditional pharmacopeias. This study was conducted with experts in medicinal plants in the Cerrado (Brazilian savanna), selected through the “snowball” technique, to test if the versatility and diversity hypotheses explain the incorporation of exotic species in the popular pharmacopeia. Relative importance (RI) index was calculated for each species, as a measure of versatility. A variance analysis was performed to compare RI of native and exotic species. An analysis of similarity (ANOSIM) was used to test the differences among the types of therapeutic indication and the ICD-10 body systems, by native and exotic species. The local pharmacopeia has 108 native and 32 exotic species for the treatment of 52 health issues. The results do not support the versatility hypothesis, since native and exotic species have similar RI. However, the repertoire of native species tends to be more versatile, being suitable for treating a wider range of disorders. In spite of the overlap of native and exotic species in therapeutic indications, some exotic species are unique to the treatment of certain diseases, effectively strengthening the local pharmacopeia and thus supporting the diversification hypothesis.     

Increased Productivity of a Cover Crop Mixture Is Not Associated with Enhanced Agroecosystem Services

Cover crops provide a variety of important agroecological services within cropping systems. Typically these crops are grown as monocultures or simple graminoid-legume bicultures; however, ecological theory and empirical evidence suggest that agroecosystem services could be enhanced by growing cover crops in species-rich mixtures. We examined cover crop productivity, weed suppression, stability, and carryover effects to a subsequent cash crop in an experiment involving a five-species annual cover crop mixture and the component species grown as monocultures in SE New Hampshire, USA in 2011 and 2012. The mean land equivalent ratio (LER) for the mixture exceeded 1.0 in both years, indicating that the mixture over-yielded relative to the monocultures. Despite the apparent over-yielding in the mixture, we observed no enhancement in weed suppression, biomass stability, or productivity of a subsequent oat (Avena sativa L.) cash crop when compared to the best monoculture component crop. These data are some of the first to include application of the LER to an analysis of a cover crop mixture and contribute to the growing literature on the agroecological effects of cover crop diversity in cropping systems.     

Temporal Patterns of Species Accumulation in a Survey of Lepidoptera in a Beech-Maple Forest

One of the most significant challenges to insect conservation is lack of information concerning species diversity and distribution. Because a complete inventory of all species in an area is virtually impossible, interest has turned to developing statistical techniques to guide sampling design and to estimate total species richness within a site. We used two such techniques, diversity partitioning and non-parametric richness estimation, to determine how variation in sampling effort over time affected species accumulation for a survey of Lepidoptera in an old-growth beech-maple forest. Temporal scaling of sampling effort had significant effects on two measures of species diversity. Increases in species richness were primarily driven by changes in species occurrences with season, while Shannon diversity was largely determined at the scale of individual sampling units (i.e. by spatial effects). Variation in sampling effort affected the values of the two most widely regarded richness estimators (ICE and Chao 2); neither diversity estimator achieved stable values across a range of sampling efforts. Even after 52 trap-nights and accounting for seasonality, rare species (singletons and uniques) remained a significant component of the moth community. To the extent that moth communities in other forest systems are similarly comprised of many rare species, non-parametric richness estimators should be expected to yield variable estimates with increased effort and should only be used to provide a minimum benchmark for predicting the number of species remaining to be sampled. Our results suggest the best strategy for a short-term survey of forest Lepidoptera should emphasize spreading sampling intervals throughout a given year rather than focusing on intensive sampling during a short time period or prolonged sampling over many years.     

Cluster Analysis of Longidorus Species (Nematoda: Longidoridae), a New Approach in Species Identification

Hierarchical cluster analysis based on female morphometric character means including body length, distance from vulva opening to anterior end, head width, odontostyle length, esophagus length, body width, tail length, and tail width were used to examine the morphometric relationships and create dendrograms for (i) 62 populations belonging to 9 Longidorus species from Arkansas, (ii) 137 published Longidorus species, and (iii) 137 published Longidorus species plus 86 populations of 16 Longidorus species from Arkansas and various other locations by using JMP 4.02 software (SAS Institute, Cary, NC). Cluster analysis dendograms visually illustrated the grouping and morphometric relationships of the species and populations. It provided a computerized statistical approach to assist by helping to identify and distinguish species, by indicating morphometric relationships among species, and by assisting with new species diagnosis. The preliminary species identification can be accomplished by running cluster analysis for unknown species together with the data matrix of known published Longidorus species.     

Species convergence into life-forms in a hyperseasonal cerrado in central Brazil

Whether the functional structure of ecological communities is deterministic or historically contingent is still quite controversial. However, recent experimental tests did not find effects of species composition variation on trait convergence and therefore the environmental constraints should play the major role on community convergence into functional groups. Seasonal cerrados are characterized by a sharp seasonality, in which the water shortage defines the community functioning. Hyperseasonal cerrados experience additionally waterlogging in the rainy season. Here, we asked whether waterlogging modifies species convergences into life-forms in a hyperseasonal cerrado. We studied a hyperseasonal cerrado, comparing it with a nearby seasonal cerrado, never waterlogged, in Emas National Park, central Brazil. In each area, we sampled all vascular plants by placing 40 plots of 1 m(2) plots in four surveys. We analyzed the species convergences into life-forms in both cerrados using the Raunkiaer's life-form spectrum and the index of divergence from species to life-form diversity (IDD). The overall life-form spectra and IDDs were not different, indicating that waterlogging did not affect the composition of functional groups in the hyperseasonal cerrado. However, there was a seasonal variation in IDD values only in the hyperseasonal cerrado. As long as we did not find a seasonal variation in life-form diversity, the seasonal variation of convergence into life-forms in the hyperseasonal cerrado was a consequence of the seasonal variation of species diversity. Because of high functional redundancy of cerrado plants, waterlogging promoted a floristic replacement without major changes in functional groups. Thus, waterlogging in the hyperseasonal cerrado promoted seasonal changes in species convergence into life-forms by reducing species diversity.     

Aphid Species and Population Dynamics Associated with Strawberry

Aphids are among the major pests associated with strawberries in Southern Brasil. In this study, we identified the main species that occur in strawberry fields in the states of Paraná and Rio Grande do Sul, Brasil. We also compared the effectiveness of different sampling methods and studied the population dynamics of aphid species during two strawberry crop cycles in the municipality of Pinhais, state of Paraná, Brasil. Chaetosiphon fragaefolii (Cockerell) and Aphis forbesi Weed were the main species associated with strawberry. The method of hit plant and the Möericke trap showed equal effectiveness to capture wingless and winged insects. The peak population of aphids in the state of Paraná occurred from September to November. This information can help producers to implement strategies to monitor and control the major aphid species that occur in strawberry culture.     

Species limits in butterflies (Lepidoptera: Nymphalidae): reconciling classical taxonomy with the multispecies coalescent

Species delimitation is at the core of biological sciences. During the last decade, molecular‐based approaches have advanced the field by providing additional sources of evidence to classical, morphology‐based taxonomy. However, taxonomy has not yet fully embraced molecular species delimitation beyond threshold‐based, single‐gene approaches, and taxonomic knowledge is not commonly integrated into multilocus species delimitation models. Here we aim to bridge empirical data (taxonomic and genetic) with recently developed coalescent‐based species delimitation approaches. We use the multispecies coalescent model as implemented in two Bayesian methods (dissect/stacey and bp&p ) to infer species hypotheses. In both cases, we account for phylogenetic uncertainty (by not using any guide tree) and taxonomic uncertainty (by measuring the impact of using a priori taxonomic assignments to specimens). We focus on an entire Neotropical tribe of butterflies, the Haeterini (Nymphalidae: Satyrinae). We contrast divergent taxonomic opinion – splitting, lumping and misclassifying species – in the light of different phenotypic classifications proposed to date. Our results provide a solid background for the recognition of 22 species. The synergistic approach presented here overcomes limitations in both traditional taxonomy (e.g. by recognizing cryptic species) and molecular‐based methods (e.g. by recognizing structured populations, and not raising them to species). Our framework provides a step forward towards standardization and increasing reproducibility of species delimitations.     

Behaviour Associated with Ultrasonic Vocalizations in Six Gerbilline Rodent Species

Encounters were staged between male and oestrus-induced females of the same or different taxa of the species/subspecies Gerbillurus paeba paeba, G. p. exilis, G. tytonis, G. setzeri, G. vallinus and Tatera brantsii. Each encounter lasted 20 min; converted ultrasonic emissions were recorded on videotape simultaneously with visual images. Videotapes were transcribed and sequences of acts and vocalizations were recorded. The frequency of acts was compared separately with the number of ultrasonic vocalizations during and after acts by χ² contingency table analysis, followed by partitioned χ² to identify individual acts which contributed significantly to the overall χ² value. Vocalizations occurred significantly more frequently than expected during sexual and/or huddling behaviour in all species-groups; and significantly less frequently than expected during exploratory, watching and/or submissive behaviour. Vocalizations were uncommon during investigative behaviour in all taxa, and aggressive behaviour in Gerbillurus taxa, but occurred significantly more frequently than expected after these behaviour categories in all taxa. Analysis of vocalizations immediately following acts verified the interpretations of function of vocalizations during acts. Ultrasonic vocalizations clearly play an important role in the communication of six taxa of southern African gerbils.