THE LYCHEE TREE PROPAGATION BY LAYERING

The aim of the study was to assess the influence of season and different substrates on rooting of air layers of lychee (Litchi chinensisSonn.) for the production of seedlings to ensure the formation of uniform and productive orchards. Air layers were done in plants of the Bengal cultivar using leafy and healthy woody branches, with about 0.010 to 0.015 m in diameter, in which were performed complete girdling with 0.020 m wide at a distance of 0.30 to 0.40 m below the apex. Then the branches were wrapped in moistened substrate. The layering was made at six times of theyear (January, March, May, July, September and November) and two substrates were used (coconut fiber and sphagnum) in a 6 x 2 factorial design in a randomized block with ten replicates. After 90 days, layers were separated from the matrix plant and evaluated for rooting and callus formation, root number, considering only the primary roots, length, area and volume of the roots, beyond the dry weight of roots and calluses. The months of January, March, September and November showed the best results for all analyzed variables related to rooting. With respect to the substrates, the only difference was in January and March to the root number and dry weight of roots, where the sphagnum showed the best results. The month of July was more conducive to the formation of calluses. The period between September and March was more suitable to the propagation of lychee, when there were rooting percentages above 90%, in addition to the formation of large amount of roots.

Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated by the sediment and that the collector organisms as Chironomus species accumulated higher concentration of metals than the predator organisms.

Floral resources used by insects in a grassland community in Southern Brazil

The goal of the present study was to identify plant species used as food source, the floral resources utilized, and the insects that visit flowers in a grassland community in southern Brazil. The study was carried out in an area of one hectare, located in a grassland formation in the Parque Estadual de Itapuã, State of Rio Grande do Sul, Brazil. The flowering pattern was seasonal, and richness and abundance of insects was higher during the period of high resource availability. Flowers of 106 species of angiosperms (73 genera and 34 families) were used as source of floral resources for 219 species (2,767 specimens) of insects. A total of 91.5% of plant species were visited by bees, 53.8% by flies, 34.9% by wasps, 22.6% by butterflies, and 12.3% by beetles. Nectar was the main resource consumed by the visitors (41.1%). Asteraceae was the richest (38 spp.) and most visited family, with 63.1% of the species and 49.5% of all specimens of recorded insects. Bees were the most representative insects (33.2% spp., 65% indiv.), followed by flies (26.9% spp., 16.5% indiv.), wasps, butterflies and beetles. 40 plant species were considered important resources for the floral visitors' community, due to high number of, both, species and individuals recorded in their flowers. The family Asteraceae as a species set was the main floral resource used by insect visitors through the year and has great importance for the maintenance of populations of many species of bees, flies, wasps and butterflies in the studied area.

Indirect effect of neem oil on Podisus nigrispinus (Hemiptera, Pentatomidae): biology and predatory capacity

This study evaluated the effects on the development and predatory capacity of Podisus nigrispinus fed on Spodoptera frugiperda that have ingested different concentrations of neem oil. The predatory capacity of Podisus nigrispinus was assessed, separating nymphs (fourth instar) and adults (males and females). The treatments consisted of S. frugiperda larvae reared in neem oil aqueous solutions (0.077, 0.359 and 0.599%), deltamethrin EC 25 (0.100%) and control arranged in a completely randomized design, with ten replicates. Insects were offered three larval densities (one, three and six), in the third or fourth instars. The predated larvae were examined at 24 and 48 hours after the beginning of the experiment. Biological parameters of Podisus nigrispinus were evaluated in groups of ten second-instar nymphs transferred to pots, in five replicates. Insects were offered 2-6 third and/or fourth-instar larvae reared in the same neem oil concentrations in a completely randomized design. The following parameters were evaluated: duration of each nymph stage (days), nymph mortality (%), weight of fifth-instar nymphs (mg), sex ratio, weight of males and females (mg) and longevity of unfed adults (days). The predatory capacity of nymphs and adults of Podisus nigrispinus was influenced by the neem oil at the concentrations of 0.359% and 0.599% in the highest density. The concentration of 0.359% lengthened the nymphal stage and the concentration of 0.599% reduced the weight of males.

The process of implementing answerability in contemporary Brazil

Abstract: The aim of this study was to characterize the trajectory of answerability in Brazil. In the light of studies based on the historical neo-institutionalism approach, formal institutional changes adopted at federal level between 1985 and 2014, and which favor the typical requirements of answerability - information and justification - were identified and analyzed through the content analysis technique. The conclusion is that the trajectory of answerability in contemporary Brazil can be characterized as continuous, primarily occurring through the layering strategy, and whose leitmotif, since its origin, has consisted of matters of financial and budgetary nature. Nevertheless, a recent influence of deeper democratic subjects on it has been observed.

Biting activity of Aedes scapularis (Rondani) and Haemagogus mosquitoes in Southern Brazil (Diptera: Culicidae)

The biting activity of a population of Aedes scapularis (Rondani), Haemagogus capricornii Lutz and Hg. leucocelaenus (Dyar and Shannon) in Southern Brazil was studied between March 1980 and April 1983. Data were obtained with 25-hour human bait catches in three areas with patchy residual forests, named "Jacaré-Pepira", "Lupo" Farm, and "Sta. Helena" Farm, in the highland region of S. Paulo State (Brazil). Data obtained on Ae. scapularis were compared with those formerly gathered in the "Ribeira'' Valley lowlands, and were similar, except in the "Lupo" Farm study area, where a precrepuscular peak was observed, not recorded at the "Jacaré-Pepira" site or in the "Ribeira" Valley. In all the areas this mosquito showed diurnal and nocturnal activity, but was most active during the evening crepuscular period. These observations support the hypothesis about the successful adaptation of Ae. scapularis to man-made environments and have epidemiological implications that arise from it. As for Haemagogus, results obtained on the "Lupo" and "Sta. Helena" regions agree with previous data obtained in several other regions and show its diurnal activity. The proximity of "Lupo" Farm, where Hg. capricornii and Hg. leucocelaenus showed considerable activity, to "Araraquara" city where Aedes aegypti was recently found, raises some epidemiological considerations about the possibility of urban yellow fever resurgence.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 3 - On the interaction of vector species and parasite strain in the reaction of bugs to infection by Trypanosoma cruzi

The reaction of nine vector species of Chagas' disease to infection by seven different Trypanosoma cruzi strains; Berenice, Y, FL, CL, S. Felipe, Colombiana and Gávea, are examined and compared. On the basis of the insects' ability to establish and maintain the infection, vector species could be divided into two distinct groups which differ in their reaction to an acute infection by T. cruzi. While the proportion of positive bugs was found to be low in Triatoma infestans and Triatoma dimidiata it was high, ranging from 96.9% to 100% in the group of wild (Rhodnius neglectus, Triatoma rubrovaria)and essentially sylvatic vectors in process of adaptation to human dwellings, maintained under control following successful insecticidal elimination of Triatoma infestans (Panstrongylus megistus, Triatoma sordida and Triatoma pseudomaculata). An intermediate position is held by Triatoma brasiliensis and Rhodnius prolixus. This latter has been found to interchange between domestic and sylvatic environments. The most important finding is the strikingly good reaction between each species of the sylvatic bugs and practically all T. cruzi strains herein studied, thus indicating that the factors responsible for the excellent reaction of P.megistus to infection by Y strain, as previously reported also come into operation in the reaction of the same vector species to acute infections by five of the remaining T.cruzi strains. Comparison or data reported by other investigators with those herein described form the basis of the discussion of Dipetalogaster maximus as regards its superiority as a xenodiagnostic agent.

Diptera of sanitary importance associated with composting of biosolids in Argentina

OBJECTIVE: Odorous compounds produced at the biosolids composting plant in Bariloche (NW Patagonia) attract a variety of insects, mainly belonging to the order Diptera. In order to characterize these flies, collected specimens were taxonomically identified, their community characteristics were described and their sanitary and synanthropic importance and autochthonous or introduced character were determined. METHODS: Sampling was performed from October 1999 until March 2000. Adults were collected using an entomological net, and larvae and puparia were obtained from the composting material and incubated to obtain adults. Richness, abundance and sex ratio were calculated. RESULTS: A total of 9 taxa of Diptera were identified: Sarconesia chlorogaster, Phaenicia sericata, Calliphora vicina, Cochliomya macellaria, Ophyra sp, Muscina stabulans, Musca domestica, Sarcophaga sp and Fannia sp. Specimens of Anthomyiidae, Acaliptratae and one larva of Eristalis tenax were also found. Ophyra sp. was the most abundant taxa. All the captured Diptera belonged to introduced taxa. Most of them are considered to be eusynanthropic and/or hemisynanthropic and have sanitary importance as they may cause myiasis and pseudomyiasis. The high number of females registered and the finding of immature stages indicated that flies can develop their complete life cycle on biosolid composting windrows. CONCLUSIONS: The characterization of flies obtained in this study may be useful for defining locations of urban or semi-urban composting facilities. It also highlights the importance of sanitary precautions at such plants.

Resistance of Aedes aegypti to temephos and adaptive disadvantages

OBJECTIVE To evaluate the resistance of Aedes aegypti to temephos Fersol 1G (temephos 1% w/w) associated with the adaptive disadvantage of insect populations in the absence of selection pressure. METHODS A diagnostic dose of 0.28 mg a.i./L and doses between 0.28 mg a.i./L and 1.40 mg a.i./L were used. Vector populations collected between 2007 and 2008 in the city of Campina Grande, state of Paraíba, were evaluated. To evaluate competition in the absence of selection pressure, insect populations with initial frequencies of 20.0%, 40.0%, 60.0%, and 80.0% resistant individuals were produced and subjected to the diagnostic dose for two months. Evaluation of the development of aquatic and adult stages allowed comparison of the life cycles in susceptible and resistant populations and construction of fertility life tables. RESULTS No mortality was observed in Ae. aegypti populations subjected to the diagnostic dose of 0.28 mg a.i./L. The decreased mortality observed in populations containing 20.0%, 40.0%, 60.0%, and 80.0% resistant insects indicates that temephos resistance is unstable in the absence of selection pressure. A comparison of the life cycles indicated differences in the duration and viability of the larval phase, but no differences were observed in embryo development, sex ratio, adult longevity, and number of eggs per female. CONCLUSIONS The fertility life table results indicated that some populations had reproductive disadvantages compared with the susceptible population in the absence of selection pressure, indicating the presence of a fitness cost in populations resistant to temephos.

Natural Trypanosoma cruzi infection in dogs of endemic areas of the Argentine Republic

The population dynamics and the prevalence of chagasic infection of 352 dogs living in 108 rural houses infested by triatomines were studied. The region was divided into three sections according to increasing distances to an urban area. Each animal was identified by means of its particular characteristics and built, and its owners gave information about its habits. By means of xenodiagnosis, serology and ECG studies, prevalences of infection, parasitological-serological correlation, percentage of altered electrocardiographic outlines and percentage of houses with parasitemic dogs, were determined. The rural area showed a characteristic T. cruzi infection pattern and differences in the canine population parameters with respect to the other areas were observed: a higher proportion of puppies than adult dogs, a more sedentary population, higher prevalences of infection, as measured by xenodiagnosis, in dogs, and the highest proportion of bedroom insects infected with T. cruzi. It is assumed that the sedentary characteristics of the human population in that rural area impinge in the blood offer to the triatomine population, and the high percentage of parasitemic dogs of the area, contribute to the rise of "kissing ougs" infected with T. cruzi found in bedrooms.

Lethality of triatomines (Hemiptera: Reduviiae), vectors of Chagas' disease, feeding on blood baits containing synthetic insecticides, under laboratory conditions

A laboratory study was conducted to test the toxicity of synthetic insecticides added to defibrinated sheep blood kept at room temperature and offered as food to the following triatomine species: Triatoma infestans, Panstrongylus megistus, Triatoma vitticeps, Triatoma pseudomaculata, Triatoma brasiliensis and Rhodnius prolixus. The insecticides used, at a concentration of 1g/l, were: HCH, DDT, Malathion and Trichlorfon, and the lethalithy observed at the end of a 7-day period varied according to the active principle of each. HCH was the most effective by the oral route, killing 100% of the insects, except P. megistus (95.7%) and T. pseudomaculata (94.1%). Trichlorfon killed the insects at rates ranging from 71.8% (T. vitticeps) to 98% (R. prolixus). Malathion was slightly less efficient, killing the insects at rates from 56.8% (T. vitticeps) to 97% (T.brasiliensis). DDT was the least effective, with a killing rate of 10% (T. vitticeps) to 75% (T.brasiliensis). Since the tests were performed at room temperature, we suggest that baits of this type should be tried for the control of triatomines in the field.

Embryology of Triatoma infestans (KLUG), (Hemiptera, Reduviidae), a Chagas' disease vector

This study reports the embryogenesis of T. infestans (Hemiptera, Reduviidae). Morphological parameters of growth sequences from oviposition until hatching (12-14 d 28ºC) were established. Five periods, as percent of time of development (TD), were characterized from oviposition until hatching. The most important morphological features were: 1) formation of blastoderm within 7% of TD; 2) germ band and gastrulation within 30% of TD; 3) nerve cord, limb budding, thoracic and abdominal segmentation and formation of body cavity within 50% of TD; 4) nervous system and blastokinesis end, and development of embryonic cuticle within 65% of TD; 5) differentiation of the mouth parts, fat body, and Malphigian tubules during final stage and completion of embryo at day 12 to day 14 around hatching. These signals were chosen as appropriate morphological parameters which should enable the evaluation of embryologic modifications due to the action/s of different insecticides

Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae)

DNA amplification by the polymerase chain reaction (PCR) was applied in the investigation of the presence of Leishmania (Kinetoplastida: Trypanosomatidae) parasites in single phlebotomine sandflies. Three phlebotomine/parasite pairs were used: Lutzomyia longipalpis/Leishmania chagasi, Lutzomyia migonei/Leishmania amazonensis and Lutzomyia migonei/Leishmania braziliensis, all of them incriminated in the transmission of visceral or cutaneous leishmaniasis. DNA extraction was performed with whole insects, with no need of previous digestive tract dissection or pooling specimens. The presence of either mouse blood in the digestive tract of the sandflies or the digestive tract itself did not interfere in the PCR. Infection by as few as 10 Leishmania sp. per individual were sufficient for DNA amplification with genus-specific primers. Using primers for L. braziliensis and L. mexicana complexes, respectively, it was possible to discriminate between L. braziliensis and L. amazonensis in experimentally infected vectors (L. migonei).

Cryptococcus neoformans strains isolated from church towers in Rio de Janeiro City, RJ, Brazil

Cryptococcosis has been a significant cause of morbidity and mortality in patients with Aids. Many reservoirs of the agent Cryptococcus neoformans have been reported, but the ecology of this yeast must be elucidated in order to establish surveillance programs and to prevent infections. The objective of this study was to evaluate the presence of C. neoformans in Rio de Janeiro City, RJ, Brazil. Ten churches were selected for sampling and detection of the yeast collecting pigeon dropping, air samples from church towers and neighboring areas during one year. The data demonstrated that C. neoformans has been present in every church selected and was present in 37.8% of 219 pigeon dropping samples. As well as, the yeast was isolated from soil, insects, eggs, pigeon nests and feathers. Fifteen air samples (4.9%) were positive. The growth on C.G.B. medium showed that all strains belonged to C. neoformans var. neoformans, with 98.8% of the strains belonging to serotype A.

Survival of Trypanosoma cruzi in sugar cane used to prepare juice

Chagas disease can be transmitted to man by many different means, including contact with infected triatomine feces, blood transfusion, laboratory accidents, organ transplants, and congenital or oral routes. The latter mode has received considerable attention recently. In this assay, we evaluate the survival of Trypanosoma cruzi contaminating sugar cane used to prepare juice, as well as the viability and capacity for infection by the parasite after recovery. Thirty triatomines were contaminated with T. cruzi Y strain and 45 days later pieces of sugar cane were contaminated with the intestinal contents of the insects. The pieces were ground at different intervals after contamination (time = 0, 1, 4, 6, 12 and 24 hours) and the juice extracted and analyzed. Different methods were used to show T. cruzi in the juice: direct analysis, hematocrit tube centrifugation and QBC, and experimental inoculation in 47 female BALB/c mice (five control mice and seven mice for each interval examined (five inoculated orally and two intraperitoneally). Positive results were found using the direct analysis and QBC methods for juice prepared up to 12 hours after initial contamination. However, by the centrifugation technique, positivity was found only up to four hours after contamination of the sugar cane. Inoculated animals showed parasitemia during a 14 day observation period, demonstrating the high survival rate of T. cruzi in sugar cane.