Development and feeding behavior of <Emphasis Type="Italic">Helicoverpa armigera</Emphasis> (Hübner) (Lepidoptera: Noctuidae) on different sunflower genotypes under laboratory conditions

The aim of this study was to assess the biological aspects and food preferences of Helicoverpa armigera fed different sunflower genotypes and an artificial diet. Tests were performed under multiple-choice and no-choice conditions to evaluate the biological characteristics of H. armigera. In addition, the biological data obtained were used to determine parameters of fertility life tables. The results showed that H. armigera does not have a feeding preference among the sunflower genotypes tested. The larval period on sunflower ranged from 15.0 to 16.2 days. The maximum fecundity on sunflower was 542.6 eggs/female and that on the artificial diet was 794.5 eggs/female. In general, insects feeding on Helio 250 consumed greater quantities of leaves, had higher survival until the end of the pupal stage, displayed high population growth rates, and had low population doubling times, suggesting that in the field populations will achieve greater population densities when fed on Helio 250. Insects that fed on CF101 consumed smaller leaf areas, had lower survival until the end of the pupal stage, lower fertility rates, and lower population growth rates, and may also have displayed lower population densities and smaller reductions in field productivity. This insect developed best on an artificial diet in comparison to sunflower genotypes studied.     

Evolutionary changes in the complexity of the tectum of nontetrapods: a cladistic approach

Background

The tectum is a structure localized in the roof of the midbrain in vertebrates, and is taken to be highly conserved in evolution. The present article assessed three hypotheses concerning the evolution of lamination and citoarchitecture of the tectum of nontetrapod animals: 1) There is a significant degree of phylogenetic inertia in both traits studied (number of cellular layers and number of cell classes in tectum); 2) Both traits are positively correlated accross evolution after correction for phylogeny; and 3) Different developmental pathways should generate different patterns of lamination and cytoarchitecture.

Methodology/Principal Findings

The hypotheses were tested using analytical-computational tools for phylogenetic hypothesis testing. Both traits presented a considerably large phylogenetic signal and were positively associated. However, no difference was found between two clades classified as per the general developmental pathways of their brains.

Conclusions/Significance

The evidence amassed points to more variation in the tectum than would be expected by phylogeny in three species from the taxa analysed; this variation is not better explained by differences in the main course of development, as would be predicted by the developmental clade hypothesis. Those findings shed new light on the evolution of an functionally important structure in nontetrapods, the most basal radiations of vertebrates.     

Angiotensin II contributes to arterial compliance in congestive heart failure

Arterial compliance is determined by structural factors, such as collagen and elastin, and functional factors, such as vasoactive neurohormones. To determine whether angiotensin II contributes to decreased arterial compliance in patients with heart failure, this study tested the hypothesis that administration of an angiotensin-converting enzyme inhibitor improves arterial compliance. Arterial compliance and stiffness were determined by measuring carotid artery diameter, using high-resolution duplex ultrasonography, and blood pressure in 23 patients with heart failure secondary to idiopathic dilated cardiomyopathy. Measurements were made before and after intravenous administration of enalaprilat (1 mg) or vehicle. Arterial compliance was inversely related to both baseline plasma angiotensin II (r = -0.52; P = 0.015) and angiotensin-converting enzyme concentrations (r = -0.45; P = 0.041). During isobaric conditions, enalaprilat increased carotid artery compliance from 3.0 +/- 0.4 to 5.0 +/- 0.4 x 10(-10) N(-1). m(4) (P = 0.001) and decreased the carotid artery stiffness index from 17.5 +/- 1.8 to 10.1 +/- 0.6 units (P = 0.001), whereas the vehicle had no effect. Thus angiotensin II is associated with reduced carotid arterial compliance in patients with congestive heart failure, and angiotensin-converting enzyme inhibition improves arterial elastic properties. This favorable effect on the pulsatile component of afterload may contribute to the improvement in left ventricular performance that occurs in patients with heart failure treated with angiotensin-converting enzyme inhibitors.     

Identification of the origin of replication of the Mycoplasma pulmonis chromosome and its use in oriC replicative plasmids

Mycoplasma pulmonis is a natural rodent pathogen, considered a privileged model for studying respiratory mycoplasmosis. The complete genome of this bacterium, which belongs to the class Mollicutes, has recently been sequenced, but studying the role of specific genes requires improved genetic tools. In silico comparative analysis of sequenced mollicute genomes indicated the lack of conservation of gene order in the region containing the predicted origin of replication (oriC) and the existence, in most of the mollicute genomes examined, of putative DnaA boxes lying upstream and downstream from the dnaA gene. The predicted M. pulmonis oriC region was shown to be functional after cloning it into an artificial plasmid and after transformation of the mycoplasma, which was obtained with a frequency of 3 x 10(-6) transformants/CFU/ micro g of plasmid DNA. However, after a few in vitro passages, this plasmid integrated into the chromosomal oriC region. Reduction of this oriC region by subcloning experiments to the region either upstream or downstream from dnaA resulted in plasmids that failed to replicate in M. pulmonis, except when these two intergenic regions were cloned with the tetM determinant as a spacer in between them. An internal fragment of the M. pulmonis hemolysin A gene (hlyA) was cloned into this oriC plasmid, and the resulting construct was used to transform M. pulmonis. Targeted integration of this genetic element into the chromosomal hlyA by a single crossing over, which results in the disruption of the gene, could be documented. These mycoplasmal oriC plasmids may therefore become valuable tools for investigating the roles of specific genes, including those potentially implicated in pathogenesis.     

The conservation value of cacao agroforestry for bird functional diversity in tropical agricultural landscapes

Cacao agroforestry have been considered as biodiversity‐friendly farming practices by maintaining habitats for a high diversity of species in tropical landscapes. However, little information is available to evaluate whether this agrosystem can maintain functional diversity, given that agricultural changes can affect the functional components, but not the taxonomic one (e.g., species richness). Thus, considering functional traits improve the understanding of the agricultural impacts on biodiversity. Here, we measured functional diversity (functional richness‐FD, functional evenness‐FEve, and functional divergence‐Rao) and taxonomic diversity (species richness and Simpson index) to evaluate changes of bird diversity in cacao agroforestry in comparison with nearby mature forests (old‐growth forests) in the Brazilian Atlantic Forest. We used data from two landscapes with constraining areas of mature forest (49% Una and 4.8% Ilhéus) and cacao agroforestry cover (6% and 82%, respectively). To remove any bias of species richness and to evaluate assembly processes (functional overdispersion or clustering), all functional indices were adjusted using null models. Our analyses considered the entire community, as well as separately for forest specialists, habitat generalists, and birds that contribute to seed dispersal (frugivores/granivores) or invertebrate removal (insectivores). Our findings showed that small cacao agroforestry in the forested landscape sustains functional diversity (FD and FEve) as diverse as nearby forests when considering the entire community, forest specialist, and habitat generalists. However, we observed declines for frugivores/granivores and insectivores (FD and Rao). These responses of bird communities differed from those observed by taxonomic diversity, suggesting that even species‐rich communities in agroforestry may capture lower functional diversity. Furthermore, communities in both landscapes showed either functional clustering or neutral processes as the main driver of functional assembly. Functional clustering may indicate that local conditions and resources were changed or lost, while neutral assemblies may reveal high functional redundancy at the landscape scale. In Ilhéus, the neutral assembly predominance suggests an effect of functional homogenization between habitats. Thus, the conservation value of cacao agroforestry to harbor species‐rich communities and ecosystem functions relies on smallholder production with reduced farm management in a forested landscape. Finally, we emphasize that seed dispersers and insectivores should be the priority conservation targets in cacao systems.     

Sensory ecology of ostariophysan alarm substances

Chemical communication of predation risk has evolved multiple times in fish species, with conspecific alarm substance (CAS) being the most well understood mechanism. CAS is released after epithelial damage, usually when prey fish are captured by a predator and elicits neurobehavioural adjustments in conspecifics which increase the probability of avoiding predation. As such, CAS is a partial predator stimulus, eliciting risk assessment-like and avoidance behaviours and disrupting the predation sequence. The present paper reviews the distribution and putative composition of CAS in fish and presents a model for the neural processing of these structures by the olfactory and the brain aversive systems. Applications of CAS in the behavioural neurosciences and neuropharmacology are also presented, exploiting the potential of model fish [e.g., zebrafish Danio rerio, guppies Poecilia reticulata, minnows Phoxinus phoxinus) in neurobehavioural research.     

Validation of the recently developed aromaticity index D3BIA for benzenoid systems. Case study: acenes

There are four types of aromaticity criteria: energetic, electronic, magnetic and geometric. The delocalization, density and degeneracy-based index of aromaticity, D3BIA, is an electronic aromaticity index from QTAIM that is not reference dependent and can be used for aromatic, homoaromatic, sigma aromatic and other aromatic systems with varying ring size containing hetereoatoms or not. We used B3LYP, MP2 and MP3 methods to search for linear relations between well-known aromaticity indices and D3BIA for a series of acenes. We found that the D3BIA versus FLU correlation exceeded 91 % and reasonably good correlations exist between D3BIA and HOMA and between D3BIA and PDI. Previous works have shown that D3BIA can be used for homoaromatic systems and tetrahedrane derivatives (sigma aromaticity), but no previous work has validated D3BIA for benzenoid systems. This is the first time we have shown that D3BIA can be used successfully for benzenoid systems, for example, acenes. This work supports and validates the use of D3BIA in classical aromatic systems.

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Graphical Abstract Linear relations of D3BIA with FLU, PDI and HOMA for acenes

     

Current and future effectiveness of protected areas for the conservation of endemic owls from the Atlantic Forest

Protected areas are essential conservation tools for mitigating the rapid decline of biodiversity. However, climate change represents one of the main challenges to their long-term effectiveness, as it induces rapid changes in the geographical distribution of many species. We used ecological niche modelling to predict the impacts of climate change on the distribution of five endemic owls in the Atlantic Forest and evaluated the effectiveness of the protected areas network for their conservation. The results indicate that the protected areas network is currently effective in terms of representativeness for most species; however, there will be a decline for all species in the coming decades because of climate change. We found that the ecoregions in the northern part of the Atlantic Forest will experience a higher loss of species, whereas those ecoregions in the southern part will be important stable climatic refuges in the future. Therefore, we emphasize the need to complement the network of protected areas to increase their representativeness in the distribution of species that will be affected by climate change, reducing species loss and increasing connectivity between suitable areas. We hope the results presented herein will serve as a basis for decision-makers to re-evaluate and improve current conservation policies and decisions in order to address the challenges posed by climate change and secure the survival of these species.     

Establishment of rapid and non-invasive protocols to identify B-carrying individuals of Psalidodon paranae

Supernumerary, or B, chromosomes are present in several eukaryotes, including characid fish of the genus Psalidodon. Notably, Psalidodon paranae carries the most studied B chromosome variant, a macro-B chromosome. The origin of this element was determined to be an isochromosome; however, data regarding its inheritance remain unavailable due to methodological barriers such as the lack of an efficient, non-invasive, and rapid protocol for identifying B-carrying individuals that would enable the design of efficient crossing experiments. Thus, in this study, we primarily aimed was to develop two non-invasive and fast (approximately 2 h) methods to identify the presence of B chromosomes in live specimens of P. paranae based on satellite DNA (satDNA) sequences known to be present in this element. The methods include fluorescence in situ hybridization in interphase nuclei and relative gene quantification of satDNAs using quantitative polymerase chain reaction. Our results reveal the efficiency of quick-fluorescence in situ hybridization and quantitative polymerase chain reaction for identifying B-carrying individuals using the proposed satDNA sequences and open up new possibilities to study B chromosomes.     

Foraging activity of leaf-cutter ants is affected by barometric pressure

Among all activities displayed by ant colonies, searching for food is essential for all individuals survival. However, many external activities are hazardous or restrictive for the entire society. Even though leaf-cutter ants are highly successful insects, they are subject to extreme aspects of foraging, as raindrops and wind. Although recruitment and food exploitation are known to change with temperature and humidity, barometric pressure changes and how they affect ant behavior remain unknown. We aimed to determine how an increase or decrease in barometric pressure might modify foraging strategies of the leaf-cutter ant Atta sexdens compared to steady pressure. The first modification observed in the workers behavior was the scouts greater promptness in leaving the nest when the barometric pressure decreased. Regard to the foragers, there was no difference in the number of individuals recruited for collecting leaves. However, it was cut and brought into the nest 1.5 and 2 times more leaves during the pressure drop, respectively. The reason for this foraging efficiency as a whole was ultimately the sum of the efficiency of each forager. The shifts in behavior, therefore, could be related to the indirect consequences of a pressure decrease, such as rainfall and strong winds, both strong constraints on ants on a trail. This is the first report of barometric pressure affecting the behavior of a social insect under controlled conditions.