HOST-SPECIFICITY OF SEVERAL PSEUDACTEON (DIPTERA, PHORIDAE) PARASITES OF FIRE ANTS (HYMENOPTERA, FORMICIDAE) IN SOUTH-AMERICA

We tested the host specificity of several parasitic Pseudacteon scuttle flies in South America with 23 species of ants in 13 genera. None of these ant species attracted Pseudacteon parasites except Solenopsis saevissima (F. Smith) and to a lesser extent Solenopsis geminata (Fab.). This result is encouraging because it indicates that the Pseudacteon flies tested in this study would not pose an ecological danger to other ant genera if these flies were introduced into the United States as classical biological control agents of imported fire ants. This prediction of host specificity will, of course, need to be validated with potential hosts in the United States before these flies can be released.

Host specificity of Metriona elatior, a potential biological control agent of tropical soda apple, Solanum viarum, in the USA

The leaf beetle Metriona elatior from Brazil-Argentina was screened in the Florida (USA) State quarantine facility as a potential biological control agent of tropical soda apple, Solanum viarum, a recently arrived weed species. Multiple-choice host-specificity tests were conducted in small cages (60 cm x 60 cm x 60 cm) using 95 plant species in 29 families. Adults fed heavily on the main target weed (S. viarum), and on turkeyberry, Solanum torvum (noxious weed of Asiatic origin); fed moderately on red soda apple, Solanum capsicoides (weed of South American origin), and eggplant, Solanum melongena (economic crop); and fed lightly on aquatic soda apple, Solanum tampicense (weed of Mexican-Caribbean-Central American origin), and on silverleaf nightshade, Solanum elaeagnifolium (native weed widely distributed). M. elatior adults laid 84 to 97% of their egg masses on S. viarum, and 3 to 16% on S. melongena. Non-choice host-specificity tests were also conducted in quarantine in which M. elatior adults and neonate larvae were exposed to 17 and 19 plant species, respectively. Tests with the neonates indicate that this insect was able to complete its development on S. viarum, S. torvum, S. melongena, and S. capsicoides. Although some adult feeding and oviposition occurred on S. melongena in quarantine on potted plants in small cages, no feeding or oviposition by M. elatior was observed in field experiments conducted in Brazil. Surveys in unsprayed S. melongena fields in Argentina and Brazil indicated that M. elatior is not a pest of S. melongena in South America. The evidence obtained from the South-American field surveys, Brazil open-field experiments, and Florida quarantine host specificity tests indicate that M. elatior causes significant feeding damage to S. viarum, and does not represent a threat to S. melongena crops in the USA. Therefore an application for permission to release M. elatior against S. viarum in the USA was submitted in October 1998.

Trail-Pheromone Specificity of Two Sympatric Termites (Rhinotermitidae) from Southeastern Brazil

Studies on pheromone specificity are of ecological interest in termite biology where different species share the same habitat. In this work we evaluated the role of the trail pheromones as a mechanism for the isolation of sympatric populations of Coptotermes gestroi and Heterotermes tenuis (Rhinotermitidae) in Brazil. Based on our results, we conclude that trail pheromones are potentially capable of separating sympatric colonies of these species. Furthermore, the trail-pheromone specificity found in these species could be explained by quantitative differences of the common component of the trail pheromone. However, secondary components on the trail pheromone may neutralize the quantitative differences of a common component. Activity bioassays showed that synthetic (Z,Z,E) 3,6,8-dodecatrien-1-ol may act as the common component of the trail pheromone of these species. Further studies should focus on the chemical identification of the trails laid by the termites.

The specificity of the Latin American State

Includes bibliography

Lack of host specificity of Colletotrichum spp. isolates associated with anthracnose symptoms on mango in Brazil

The aim of the present study was to analyse the genetic and pathogenic variability of Colletotrichum spp. isolates from various organs and cultivars of mango with anthracnose symptoms, collected from different municipalities of São Paulo State, Brazil. Colletotrichum gloeosporioides isolates from symptomless citrus leaves and C. acutatum isolates from citrus flowers with post-bloom fruit drop symptoms were included as controls. Sequencing of the ITS region allowed the identification of 183 C. gloeosporioides isolates from mango; only one isolate was identified as C. acutatum. amova analysis of ITS sequences showed larger genetic variability among isolates from the same municipality than among those from different populations. fAFLP markers indicated high levels of genetic variability among the C. gloeosporioides isolates from mango and no correlation between genetic variability and isolate source. Only one C. gloeosporioides mango isolate had the same genotype as the C. gloeosporioides isolates from citrus leaves, as determined by ITS sequencing and fAFLP analysis. Pathogenicity tests revealed that C. gloeosporioides and C. acutatum isolates from either mango or citrus can cause anthracnose symptoms on leaves of mango cvs Palmer and Tommy Atkins and blossom blight symptoms in citrus flowers. These outcomes indicate a lack of host specificity of the Colletotrichum species and suggest the possibility of host migration. © 2012 British Society for Plant Pathology.

The Identification and Biochemical Properties of the Catalytic Specificity of a Serine Peptidase Secreted by Aspergillus fumigatus Fresenius

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

Elapid Snake Venom Analyses Show the Specificity of the Peptide Composition at the Level of Genera Naja and Notechis

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

Sensitivity and specificity of serological tests, histopathology and immunohistochemistry for detection of Toxoplasma gondii infection in domestic chickens

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Crystal structure of Staphylococcus aureus exfoliative toxin D-like protein: structural basis for the high specificity of exfoliative toxins

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

Host Specificity of Calyptospora funduli (Apicomplexa: Calyptosporidae) in Atheriniform Fishes

Calyptospora funduli has a broad host specificity, infecting at least 7 natural and 10 additional experimental definitive hosts, all atheriniform fishes within 5 families, but most in the genus Fundulus. Barriers, apparently innate ones, prevent any development of C. funduli in perciform fishes but allow incomplete or abnormal development of the parasite in a few unnatural atheriniform hosts. In the freshwater species Fundulus olivaceus and Fundulus notti, these abnormalities consisted of asynchronous development, degeneration of the parasite in early stages of development, and the formation of numerous macrophage aggregates. Rivulus marmoratus has the ability to eliminate infections with a granulomatous inflammatory response. Additional barriers that limit natural infections of C. funduli in other hosts include feeding behavior, environmental conditions, and geographic isolation.

Distribution and Specificity of Helminths in Microtine Rodents: Evolutionary Implications

The taxonomic status of anoplocephaline cestodes of microtine rodents has been reviewed. Of the genus Andrya Railliet, 1883, five species are considered valid: A. macrocephala Douthitt, 1915; A. primordialis Douthitt, 1915; A. montana Kirshenblat, 1941 ; A. arctica Rausch, 1952; A. bairdi Schad, 1954. Of the genus Paranoplocephala Luehe, 1910, six species are regarded as valid: P. omphalodes (Hermann, 1783); P. blanchardi (Moniez, 1891); P. infrequens (Douthitt, 1915); P. variabilis (Douthitt, 1915); P. lemmi Rausch, 1952; P. neofibrinus Rausch, 1952. Andrya caucasica Kirshenblat, 1938, and A. bialowizensis Soltys, 1949, are regarded as synonyms of A. macrocephala. Paranoplocephala brevis Kirshenblat, 1938, is regarded as a synonym of P. infrequens. Three species, A. macrocephala, P. omphalodes, and P. infrequens, are holarctic in distribution, occurring mainly in species of Microtus. The uniformity of microtine rodents as hosts for various helminths has been discussed. It is concluded that Dicrostonyx is the most isolated genus from this standpoint, having two nematodes which have not been recorded from members of other genera, and harboring few helminths in common with others. This agrees with Hinton's conclusions, based on morphological characters of Dicrostonyx. From the present concept of Pleistocene glaciations, it is concluded that P. omphalodes and P. infrequens reached the St. Matthew Islands, in Bering Sea, as parasites of a vole from which Microtus abbreviatus has evolved. It appears that this vole arrived on these islands before North America was invaded, in the late Pleistocene, by the palearctic M. oeconomus and Clethrionomys rutilus,/i>. The present known distribution of P. omphalodes in North America corresponds about to that of M. oeconomus on the continent.

Host-Specificity of Myxoma Virus: Pathogenesis of South American and North American Strains of Myxoma Virus in Two North American Lagomorph Species

The pathogenesis of South American and North American myxoma viruses was examined in two species of North American lagomorphs, Sylvilagus nuttallii (mountain cottontail) and Sylvilagus audubonii (desert cottontail) both of which have been shown to have the potential to transmit the South American type of myxoma virus. Following infection with the South American strain (Lausanne, Lu), S. nuttallii developed both a local lesion and secondary lesions on the skin. They did not develop the classical myxomatosis seen in European rabbits (Oryctolagus cuniculus). The infection at the inoculation site did not resolve during the 20-day time course of the trial and contained transmissible virus titres at all times. In contrast, S. audubonii infected with Lu had very few signs of disseminated infection and partially controlled virus replication at the inoculation site. The prototype Californian strain of myxoma virus (MSW) was able to replicate at the inoculation site of both species but did not induce clinical signs of a disseminated infection. In S. audubonii, there was a rapid response to MSW characterized by a massive T lymphocyte infiltration of the inoculation site by day 5. MSW did not reach transmissible titres at the inoculation site in either species. This might explain why the Californian myxoma virus has not expanded its host-range in North America.

Premotor and occipital theta asymmetries as discriminators of memory- and stimulus-guided tasks

The saccadic paradigm has been used to investigate specific cortical networks involving visuospatial attention. We examined whether asymmetry in theta and beta band differentiates the role of the hemispheres during the execution of two different prosacadic conditions: a fixed condition, where the stimulus was presented at the same location; and a random condition, where the stimulus was unpredictable. Twelve healthy volunteers (3 male; mean age: 26.25) performed the task while their brain activity pattern was recorded using quantitative electroencephalography. We did not find any significant difference for beta, slow- and fast-alpha frequencies for the pairs of electrodes analyzed. The results for theta band showed a superiority of the left hemisphere in the frontal region when responding to the random condition on the right, which is related to the planning and selection of responses, and also a greater activation of the right hemisphere during the random condition, in the occipital region, related to the identification and recognition of patterns. These results indicate that asymmetries in the premotor area and the occipital cortex differentiate memory- and stimulus-driven tasks. (C) 2011 Elsevier Inc. All rights reserved.