Population dynamics of phytophagous and predaceous mites on coffee in Brazil, with emphasis on Brevipalpus phoenicis (Acari: Tenuipalpidae)

The objective of this work was to study the population dynamics of Brevipalpus phoenicis (Geijskes) and predaceous mites (Phytoseiidae and Stigmaeidae), as well as the interactions among these mite species, in a coffee plantation in the State of São Paulo, Brazil. Tydeids were also evaluated because of the high frequency of these mites on coffee plants. Samples of leaves, branches and fruits were taken fortnightly, from April 2001 to June 2003, from plants randomly chosen in the coffee plantation. B. phoenicis mites were found on leaves in higher number during the drier periods of the year. Among the predaceous mites, Euseius citrifolius Denmark &; Muma and Euseius concordis (Chant) were the most frequent species on the surface of leaves. During the evaluations, 72,534 domatia were cut and opened to remove the mites, from 6,360 leaves examined. Zetzellia malvinae Matioli, Ueckermann &; Oliveira was the most frequent predator species found inside domatia. Significant correlations were observed between population dynamics of, among others, E. concordis and B. phoenicis, Z. malvinae and B. phoenicis, and Z. malvinae and E. concordis. Significant correlations were also verified between the number of domatia and the population densities of B. phoenicis, E. concordis, Lorryia sp. and Z. malvinae. Interactions between predator–prey and predator–predator on coffee plants are discussed. The influence of the meteorological factors temperature and precipitation on the most frequent mite species is also discussed.     

A revision of the genus Neogrubea Dillon & Hargis, 1968 (Monogenea: Mazocraeidae): new morphological and molecular data from off the Patagonian coast of Argentina

The genus Neogrubea Dillon & Hargis, 1968 (syn. Asymmetria Suriano, 1975) is revised based on examination of type- and voucher material, and from new specimens collected from the gills of Seriolella porosa Guichenot and Stromateus brasiliensis Fowler from off Patagonia, Argentina. Morphological comparisons based on light and scanning electron microscopy and molecular data (partial SSU and LSU rDNA sequences) of the monogeneans from off Patagonia suggest that N. seriolellae Dillon & Hargis, 1968 (syns N. stromateae Gibson, 1976, A. asymmetria Suriano, 1975 and A. platensis Rey & Meneses, 1985) is currently the only species of the genus. Neogrubea soni Evdokimova, 1969 is considered a species inquirenda. An emended diagnosis of Neogrubea is presented, and new host and locality records for N. seriolellae are given in detail. Morphological characters of the members of the mazocraeid subfamily Grubeinae Price, 1961 are also discussed.     

Spatial distribution and aggregation of Xenobalanus globicipitis on the flukes of striped dolphins,Stenella coeruleoalba: An indicator of host hydrodynamics?

We analyzed patterns of aggregation and spatial distribution of the epizoic barnacle Xenobalanus globicipitis on the flukes of Mediterranean striped dolphins, Stenella coeruleoalba, assessing its potential use as an indicator of the host's hydrodynamics based on data from 55 dolphins. Barnacles occurred along the trailing edge with the cirri oriented towards the oncoming flow. Nearest neighbor analyses suggested that new recruits actively seek placement next to already settled barnacles, forming aggregations possibly to facilitate copulation. The probability of spanwise settlement strongly increased with fluke width (presumably enabling prolonged leading-edge vorticity), and with chordwise length where pressure is predicted to be positive. Consequently, clustering tended to increase nonlinearly towards the fluke notch. Furthermore, it was three times more likely for barnacles to occur on the dorsal vs. ventral side of flukes, at an average abundance ca. 12 times higher. This difference could result from a host's asymmetric oscillation of the tail, which would alter leading-edge vorticity, and/or an interaction between the wake produced by the dorsal fin and the flow associated with flukes. Both processes could primarily enhance cyprid contact and/or attachment on the dorsal side. This study offers a starting point for future comparison with other cetaceans.     

γδ T lymphocytes from cystic fibrosis patients and healthy donors are high TNF-α and IFN-γ-producers in response to Pseudomonas aeruginosa

Background

γδ T cells have an important immunoregulatory and effector function through cytokine release. They are involved in the responses to Gram-negative bacterium and in protection of lung epithelium integrity. On the other hand, they have been implicated in airway inflammation.

Methods

The aim of the present work was to study intracytoplasmic IL-2, IL-4, IFN-γ and TNF-α production by γδ and αβ T lymphocytes from cystic fibrosis patients and healthy donors in response to Pseudomonas aeruginosa (PA). Flow cytometric detection was performed after peripheral blood mononuclear cells (PBMC) culture with a cytosolic extract from PA and restimulation with phorbol ester plus ionomycine. Proliferative responses, activation markers and receptor usage of γδ T cells were also evaluated.

Results

The highest production of cytokine was of TNF-α and IFN-γ, γδ being better producers than αβ. No differences were found between patients and controls. The Vγ9δ2 subset of γδ T cells was preferentially expanded. CD25 and CD45RO expression by the αβ T subset and PBMC proliferative response to PA were defective in cystic fibrosis lymphocytes.

Conclusion

Our results support the hypothesis that γδ T lymphocytes play an important role in the immune response to PA and in the chronic inflammatory lung reaction in cystic fibrosis patients. They do not confirm the involvement of a supressed Th1 cytokine response in the pathogenesis of this disease.     

MITOCHONDRIAL DNA VARIABILITY OF STRIPED DOLPHINS (STENELLA COERULEOALBA) IN THE SPANISH MEDITERRANEAN WATERS

Frozen muscle samples from 44 striped dolphins stranded on the Spanish Mediterranean coasts from 1990 to 1993 have been studied by means of mitochondrial DNA (mtDNA) restriction site analysis. Thirty-five of these dolphins were affected by a die-off occurring during this time in the western Mediterranean Sea. The mtDNA from each dolphin was digested with 15 restriction endonucleases that recognized 61 different restriction sites. The specific location of these sites on the mitochondrial gene map allowed us to determine the distribution of variability along this molecule. From the restriction analysis, a total of 15 different composite patterns or haplotypes was obtained and their phylogenetic relationships established both by cladistic and phenetic methods.
Estimates of sequence divergence among the 15 haplotypes ranged from 0.148% to 0.919%. Haplotype diversity (average heterozygosity) obtained was 0.789, a high value compared to other available data on cetaceans, especially considering that only a small area of the distribution of the species has been sampled. Neither population subdivision nor any evidence of correlation between haplotype frequencies and temporal or geographic distribution of dolphins has been detected.