Temporal patterns of parasitism in Diatraea saccharalis Fabr. (Lep., Crambidae) populations at different spatial scales in sugarcane fields in Brazil

Biological control of Diatraea saccharalis is regarded as one of the best examples of successful classical biological control in Brazil. Since the introduction of the exotic parasitoid, Cotesia flavipes, from Pakistan at the beginning of the 1970s, decrease in D. saccharalis infestation in sugarcane fields has been attributed to the effectiveness of this agent. Recently, the native Tachinidae fly parasitoids (Lydella minense and Paratheresia claripalpis) have also been implicated in this success. However, quantitative data confirming the actual contribution of these agents to the control of D. saccharalis are rather limited. The purpose of this study was to investigate the dynamics of the interactions between D. saccharalis and its parasitoids, emphasizing the temporal patterns of parasitism. To investigate this question, a large data set comprising information collected from two sugarcane mills located in the state of São Paulo, Brazil (Barra and Sao Joao sugarcane mills), was analysed. Basically, the data set contained monthly information about the number of D. saccharalis larvae and their parasitoids in each sample (man-hour per sample), the sugarcane varieties cultivated, the age of the sugarcane plants (only at the Sao Joao sugarcane mill) as well as the sugarcane cut at sampling time. The data were collected from March 1984 to March 1997 and from May 1982 to December 1996 for the Barra and Sao Joao sugarcane mills, respectively. Temporal inverse density-dependent parasitism was predominant for both parasitoid species with respect to all spatial scales. Although the temporal pattern of parasitism was not directly density dependent, it was evident that the tachinids and C. flavipes presented positive numerical responses according to variations in D. saccharalis densities through time.

Epiphyte plants use by birds in Brazil

This study firstly reviewed the interspecific interaction records between birds and epiphyte plants in Brazil. Forty two documents, including articles, scientific notes, books and thesis, and 35 personal records and from collaborators were argued, totaling 112 species of birds that interacted with 97 species of epiphyte plants. Two articles treated the theme specifically and another 40 treated related subjects, such as: pollination of epiphytes, ecology and feeding behavior of birds. Studies were concentrated mainly in Atlantic Forest, in the southeastern Brazilian region. The epiphyte species more visited by birds was Aechmea nudicaulis (Bromeliaceae). The main visitor of epiphytes was Ramphodon naevius (Trochilidae). According to the number of authors' citations an index of generality in bird-epiphyte interactions was created. As result the index inferred that the ovenbird Cichlocolaptes leucophrus and the bromeliad Nidularium procerum are less generalist and more specialist species in bird-epiphyte interactions. The totality of the papers showed a considerable number of bird species that use the epiphytes plants and its resources, including nectar, fruits, invertebrates, nest material, nesting place, water and bath. Considering the importance of epiphytes to supply a variety of resources for birds, these results highlighted the necessity of additional and specific studies about the theme in various Brazilian regions and biomes.

Association of the stilt bug Jalysus ossesae Henry (Hemiptera : Heteroptera : Berytidae) with myrmecophytic plants of the genus Maieta (Melastomataceae) in an upland forest area in central Amazon, Brazil

Maieta guianensis Aubl. and M. poeppigii Mart. ex. Triana (Melastomataceae) are among the most common myrmecophytic plants in the Amazonian forest understory. These myrmecophytes are colonized exclusively by the ants Pheidole minutula Mayr or Crematogaster sp. and usually host two other arthropods, the spider Faiditus subflavus Exline and Levi and the recently described stilt bug Jalysus ossesae Henry. In this study, the association between J ossesae and the myrmecophytic plants M. guianensis and M. poeppigii in an upland forest area in central Amazon, Brazil, is described. The presence of the stilt bugs on M. guianensis and M. poeppigii and on plants around these myrmecophytes was recorded in five transects. The number and position of the stilt bugs on the leaf surface (upper or lower) and leaf type (with or without domatia) of these myrmecophytes, as well as their behavioral acts, were recorded. Jalysus ossesae was found only on the myrmecophytic plants M. guianensis and M. poeppigii. The stilt bug occurred at similar frequencies on M. guianensis and M. poeppigii, and the number of leaves significantly influenced the presence and number of stilt bugs on these myrmecophytes. Feeding, agonistic interaction between males, and mating were observed. Our data indicate that J. ossesae uses the myrmecophytes M. guinanensis and M. poeppigii as reproductive and foraging sites.

Identification and characterization of a potyvirus isolated from siratro plants

The present work describes the identification and characterization of a potyvirus isolated from siratro (Macroptilium atropurpureum Urb.) in the north-west region of the State of Sdo Paulo, Brazil. The virus was transmitted by mechanical inoculation. Its host range was restricted mainly to members of the Fabaceae. A cDNA fragment of about 930 bp was amplified by RT/PCR, cloned and sequenced. The fragment, which included the coat protein gene, had amino acid identity percentages between 88 and 98% with isolates of Bean common mosaic virus (BCMV). Phylogenetic analysis grouped the. siratro potyvirus and BCMV isolates in 99% of the replicates, including Azuki mosaic virus, Dendrobium mosaic virus, Blackeye cowpea mosaic virus and Peanut stripe virus, which have been classified as BCMV strains. This is the first citation on the presence of BCMV in siratro plants in Brazil.

Mites and leaf domatia: no evidence of mutualism in Coffea arabica plants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of the medicinal plants Curcuma zedoaria and Camellia sinensis on halitosis control

Volatile sulphur compounds (VSC) are the gases mainly responsible for halitosis (bad breath). The aim of this research was to evaluate the effects of medicinal plants on halitosis control. Two commonly used plants were tested: Curcuma zedoaria and Camellia sinensis (green tea). These plants were prepared as an aqueous solution and used as mouthwashes, compared with a standard mouthwash of 0.12% chlorhexidine gluconate and a placebo (water). The experiment was conducted with 30 volunteers from the School of Dentistry of Sao Jose dos Campos, Univ. Estadual Paulista - UNESP, SP, Brazil. Each volunteer tested the four mouthwashes. The Cysteine Challenge Method, modified for this study, was used for initial breath standardization. Four breath assessments were conducted after volunteers rinsed orally with acetylcysteine: one before the test mouthwash was used; the second, one minute after its use; a third 90 minutes later; and the last 180 minutes later. The results showed that chlorhexidine gluconate lowered VSC production immediately, and that this effect lasted up to 3 hours, while the tested plants had immediate inhibitory effects but no residual inhibitory effects on VSC. We concluded that Curcuma zedoaria and Camellia sinensis, prepared as infusions and used as mouthwashes, did not have a residual neutralizing effect on VSC.

Experimental discrimination between charge 2e/3 top quark and charge 4e/3 exotic quark production scenarios

We present the first experimental discrimination between the 2e/3 and 4e/3 top quark electric charge scenarios, using top quark pairs (t (t) over bar) produced in p (p) over bar collisions at root s =1.96 TeV by the Fermilab Tevatron Collider. We use 370 pb(-1) of data collected by the D0 experiment and select events with at least one high transverse momentum electron or muon, high transverse energy imbalance, and four or more jets. We discriminate between b- and (b) over bar -quark jets by using the charge and momenta of tracks within the jet cones. The data are consistent with the expected electric charge, |q|=2e/3. We exclude, at the 92% C.L., that the sample is solely due to the production of exotic quark pairs Q (Q) over bar with |q|=4e/3. We place an upper limit on the fraction of Q (Q) over bar pairs rho < 0.80 at the 90% C.L.

Structure of large two-neutron halos in light exotic nuclei

The structure of three-body halo nuclei formed by two neutrons and a core (nnc) is studied using zero-range interactions. The halo wave function can be completely parameterized only by the s-wave scattering lengths and two-neutron separation energy. The sizes and the neutron-neutron correlation function of Li-11 and Be-14 are calculated and compared to experimental data. A general classification scheme for three-body halos with two identical particles is discussed as well as the critical conditions to allow excited Efimov states.

A few-body treatment of low energy atomic collisions involving exotic particles

Faddeev-type equations are applied to three-charged particle systems. The rather satisfactory results are obtained for low energy e(+)H elastic scattering and muonic transfer reactions. The cross sections for antihydrogen formation from antiproton-positronium collisions are calculated using a six state model (Ps[1s2s2p], (H) over bar[1s2s2p]).

Neutron-neutron correlation in the halo dissociation of light exotic nuclei

We present model results for the two-halo-neutron correlation functions, C-nn, for the dissociation process of light exotic nuclei modelled as two neutrons and a core. A minimum is predicted for C-nn as a function of the relative momentum of the two neutrons, p(nn), due to the coherence of the neutrons in the halo and final state interaction. Studying the systems Be-14, Li-11, and He-6 within this model, we show that the numerical asymptotic limit, C-nn-> 1, occurs only for p(nn)greater than or similar to 400 MeV/c, while such limit is reached for much lower values of p(nn) in an independent particle model as the one used in the analysis of recent experimental data. Our model is consistent with data once the experimental correlation function is appropriately normalized.

Structure of exotic three-body systems

The classification of large halos formed by two identical particles and a core is systematically addressed according to interparticle distances. The root-mean-square distances between the constituents are described by universal scaling functions obtained from a renormalized zero-range model. Applications for halo nuclei, Li-11 and Be-14, and for atomicn He-4(3) are briefly discussed. The generalization to four-body systems is proposed.

Schizophrenic active neutrinos and exotic sterile neutrinos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

EXOTIC CARBON SYSTEMS IN TWO-NEUTRON HALO THREE-BODY MODELS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antioxidant activity, ascorbic acid and total phenol of exotic fruits occurring in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Simultaneous Determination of Cadmium and Lead in Medicinal Plants Using Graphite Furnace Atomic Absorption Spectrometry and Direct Slurry Sampling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)