Contribuição para o conhecimento da ''saúva mata pasto" Atta bisphaerica Forel, 1908

In this paper, some notes on "saúva mata pasto" (paraol ant, Atta bisphaerica Forel, 1908) are presented. This ant is very common in good soils and it is a pest of gramineous plants, mainly com, rice, sugar cane, and so son. In poor land it is too difficult or even impossible to ind it.

A absorção do manganês pela cana de açúcar, Co 419, em função da idade

In this paper the authors have studied the manganese absorption by the sugar cane plant, variety Co 419, in samples cut monthly, from the 6th to 15th month of life in the climate prevailing at Piracicaba, State of Sao Paulo, Brazil. From October to February (6 th to 10 th month of the plant life), which coincided with the rainy season, the manganese content was higher in the stalk than in the leaves, for both treatments, fertilized and unfertilized. There was a sharp decrease in manganese content in the stalks, after February, in both reatments. In the leaves there was little variation in manganese content throughout the plant tissue. The stalks from the unfertilized plots had a larger variation in manganese content, specially from the 6 th to the 10 th month. In the leaves of the sugar cane from the unfertilized plots, the manganese content varied from 116 to 220 ppm, whereas in the fertilized treatments thire was a variation from 150 to 220 ppm. From these results, althoug not being a foliar analyses, and considering the easy availability of manganese in acid soils, there must be enough of it, if we consider 40 ppm (EVANS, 1955) as a minimum for healthy plants.

Absorção de zinco pela cana de açúcar, Co 419, em função da idade

The status of zinc in sugar cane, variety Co 419, troughout its life cyle, was studid in samples cut monthly, from the 6th to 15th month, from an experiment carried on under the conditions of soil and climate prevailing in Piracicaba, State of São Paulo, Brazil. The experiment consisted of 6plots, 3 fertilized and 3 unfertilized. The fertilized ones received 40 kg of N (ammonium sulfate), 100 kg P2O5 (superphosphate) and 40 kg K2O (potassium cloride) per hectare, just before planting. The zinc content was determined by the Zincon method, after separation of zinc from other ions by means of the ion Exchange Resin III, Merck. The results obtained show that there was a tendency to decrease the zinc level in the stalks, whereas it kept more or less constant in the leaves; there was an exception in January, when the zinc level in the stalks had a sharp raise: 38-90-20 and 28-60-23 ppm for the fertilized an unfertilized treatments. There was a parallelism in the absorption of zinc by the plants from 4 hills of both treatments, through the whole - plantcycle but, the total amount taken up was higher with the fertilized plot due to its greater mass production.

A amostragem da cana-de-açúcar para determinações tecnológicas

The authors carried out 3 experiments on the sampling of sugar cane for technological determinations, one with each of the varieties Co 419, CB 40-69 and CB 41-58, in Piracicaba, State of São Paulo, Brasil. The main intent of the project was to compare 2 methods of sampling, namely: 1) Method A, where the sample is a hill (CATANI et al, 1959) or, more generally, 20 stalks all together in a randomly selected point of the furrow; 2) Method B, where 20 stalks are taken, from 20 points evenly spread but on the whole plot. Coefficients of variation for 20 stalk samples Variety Characteristic 20 stalks per hill 1 stalk per hill Brix 4.8% 1.9% Pol 6.4% 2.5% CB 40-69 Coefficient of purity 2.1% 0.83% Available sucrose 7.3% 2.7% Weight 6.6% 6.9% Brix 5.3% 1.8% Pol 7.6% 2.6% Co 419 Coefficient of purity 2.9% 1.0% Available sucrose 8.6% 3.0% Weight 21.2% 6.5% Brix 2.8% 1.4% Pol 4.1% 1.9% CB 41-58 Coefficient of purity 1.8% 0.8% Available sucrose 5.0% 2.2% Weight 10.9% 6.2% For the 3 varieties studied and for the data on Brix, pol, coefficient of purity, available sucrose and weight, analyses of variance were carried out. Further computations led to the following coefficients of variation. For available sucrose, which is probably the most important characteristic studied, the average coefficient of variation for the 3 varieties was 2.7%, for the case of method B, that is, 20 stalk samples, one stalk per hill. Assuming this coefficient of variation, in a trial with 5 treatments and 6 replications, in randomised blocks, the least significant difference among treatment means, at the 5% level, would be 4.7% of available sucrose by Tukey's test, and 3.3% by the t test. For the case of method A the average coefficient of variation is 7.0% and, in similar conditions, the least significant difference would be 15.1% by Tukey's test, and 12.1% by the t test. Since differences of available sucrose among treatments in experiments with fertilizers seldom are higher than 3 or 4% of the mean (PIMENTEL GOMES & CARDOSO, 1958), method B with a 20 stalk sample per plot gives more or less the minimum amount of cane to be sampled for technological determinations. In experiments with varieties, however, where differences may be assumed to be higher, a sample of 10 to 20 stalks one per hill, can be enough.

A absorção de ferro pela cana de açúcar, Co 419, em função da idade

This paper describes the results obtained from the determination of iron in sugar cane according to the age of the plant, in the soil and climate conditions of the state of S. Paulo, Brazil. The iron was determined by 1-10- phenanthroline method, in samples cut monthly from 7th to 15th month from an experiment consisted de 3 plots fertilized with amonium sulfate, superphosphate and potassium cloride. The concentration of iron in the stalks and in the leaves varies according to the age of the plant. A ton of fresh stalks 15 months old contains 78,71 g of iron.

Influência do desponte sôbre a composição do colmo e do caldo da cana-de-açúcar: III. Var. CB 41-76

I. This paper deals with an experiment carried out to evaluate the effect of sugar cane upper end on the composition of the stalks and juice of sugar cane harvest as a raw material for the sugar industry. The variety studied was CB 41-76. The data were collected from plant cane at intervals of a two weeks, always from the same field, from a small central area of 3.000 square meters approximately, 60 stalks were cut in each occasion, randomly chosen from the whole area. They were afterwards separated into three groups of 20 stalks one for each of the treatments, namely: a) Complete stalk, with no leaves or sheaths. b) Stalks harvested by the technique of REYNOSO, that is, as usually done in practice. c) Stalks with the tops completely cut out, that is, cut by the techinique of REYNOSO and then with 3 other top internodes eliminated. The treatments caused significant differences on the weight of cane and coefficient of purity of juice, but the percentual differences between the average treatments a and c is 13% and 2%, respectively. II. Treatment differences for cane pol, cane fibre, brix, juice pol, reducing sugars, juice ashes, glucose coefficient, saline coefficient and available sucrose (pol) per cent were not significant. III. Time of harvest was an important factor affecting the composition of the cane and the juice. This paper shows that there is no sound basis for the heavy fines applied some sugar mills to planters who do not cut low enough the tops of the cane stalks.

Absorção de molibdênio pela cana de açúcar variedade Co 419, em função da idade

In this paper the authors describe the results obtained from the determination of molybdenum in sugar cane plant, grown in soils and climate prevailing in Piracicaba, State of São Paulo, Brazil. The molybdenum was determined in samples cut monthly from the 8th to 14th month, from an experiment consisting of 6 plots, 3 fertilized and 3 unfertilized. The fertilized treatment received 40 kg N (ammonium sulfate) 100 kg P2O3, (superphosphate) and 40 kg K2O (potassium chloride) per hectare, just before planting. Molybdenum was determined by thiocyanate-stannous chloride method, using carbon tetrachloride-butyl alcohol misture, for extrating the colored complex. The results obtained show a parallelism in the absorption of molybdenum by the plants of both treatments. The concentration of molybdenum in the stalks have a tendency to decrease, where as it kept more or less constant in leaves, with a exception in the 14° month when it rised probable because of a migration of molybdenum of the stalks to the leaves. The total amount molybdenum taken up was higher with the fertilized plot due its greater mass prodution.

Levantamento sôbre a composição química bromatológica de 39 variedades forrageiras de cana-de-açúcar

This paper deals with a survey on chemical compositions of 39 forage sugar cane varieties carried out at the Bromatology Laboratory of the E.S.A. "Luiz de Queiroz" (5th chair). Samples were taken at Sugar Cane Experimental Station "Jose Viziolli", Piracicaba, SP, and the material was analised by standard methods. The main conclusions can be summarised as follows: 1. All varieties showed low protein and mineral contents, but were high in crude fiber and nitrogen free extract fractions. 2. A small, but positive correlation was observed between crude fiber and protein content. 3. The amount of observed variation concerning the various nutrient fractions could be used to select better forage sugar cane varieties.

Capacidade reprodutiva de fêmeas de Apanteles galleriae (Hymenoptera, Braconidae) em lagartas de Galleria mellonella e Achroia grisella (Lepidoptera, Pyralidae) criadas com dietas diferentes

The reproductive capacity of females of Apanteles galleriae (Wilkinson, 1932) was evaluated in fifth instar caterpillars of Galleria mellonella (Linnaeus, 1758) and Achroia grisella (Fabricius, 1754) fed on standard diet and diets enriched with protein. The reproductive capacity of parasitoid females on fifth instar caterpillars of G. mellonella and A. grisella with variable weight was also evaluated. The host weight interfered in the sex ratio of the obtained parasitoids. In heavier caterpillars, the investment in female descendants was greater than in males, and in lighter caterpillars the inverse occurred.

Composition and diversity of bees (Hymenoptera) attracted by Moericke traps in an agricultural area in Rio Claro, state of São Paulo, Brasil

The composition and diversity of bees in an agricultural area in Rio Claro, state of São Paulo, Brazil, were studied from May 2003 to June 2004, using Moericke traps. The collection site, an area with 58.08 hectares, is characterized by grain production and direct planting, with 70% of the surrounding area planted with sugar cane. During the study, 456 bees were collected, distributed among 20 genera, pertaining to the families Andrenidae (4.8%), Apidae (40.8%) and Halictidae (54.4%). Specimens of genera Dialictus (38%) and Diadasia (30%) predominated in this area. The species diversity, assessed using the Shannon and Simpson indices, were H’=1.88 and 1/ D= 4.15, respectively, and the Evenness index was 0.61.

Potential schistosome-vector snails and associated trematodes in ricefields of Corrients province, Argentina: preliminary results

Considering the possibility of introduction of schistosomiasis mansoni into Argentina as a consequence of dam construction on the Rio De La Plata basin, preliminary studies have been carried out on agrosystems such as ricefields in Corrientes province with the following purposes: 1) to survey and estimate the relative abundance of planorbids and identify potential vector species; 2) to identify environmental factors capable of influencing Biomphalaria population dynamics; and 3) to find out snail-parasite associations and estimate snail infection rates in order to detect possible competitive interactions between larval stages of native trematodes that could be used in biological control of Schistosoma mansoni. Three potential schistosome vectors were detected in ricefields, namely Biomphalaria straminea, B. tenagophila and B. peregrina, although B. orbignyi, a species refractory to infection with S. mansoni, proved the most frequent and abundant. Positive correlations (P<0.05) were found between Biomphalaria abundance and some environmental parameters: conductivity, hardness, calcium, nitrites plus nitrates, ammonium and bicarbonates. Water temperature correlation was negative (P<0.05). No correlation (P>0.05) was found in total iron, phosphates (SRP), pH and soil granulometry. Echinocercariae developed from rediae and belonging to Petasiger sp., Paryphostomum sp., and other undetermined species were found.

Displacement of Biomfhalaria glabrata by thiara granifera under natural conditions in the Dominican Republic

After a study of the population dynamics of Biomphalaria glabrata snails in several breeding places in the Dominican Republic, the snail Thiara granifera was introduced in some B. glabrata habitats. T. granifera became established in one point in one habitat in the townof Quisqueya, in the east of the country. Around this point of establishment 6 points were selected in order to observe the population dynamics of both species of snails and the chemical and biological characteristics at each point. Four of these points already harbored B. glabrata. One control point was selected also harboring B. glabrata. After 14 months of observations, the results showed that T. granifera was competing with and displacing B. glabrata. This competition does not seem to be competition for food or vital space. Rather, B. glabrata avoids the presence of T. granifera and moves away to new areas, and this is possibly due to a chemical substance(s) secreted by T. granifera or by physical contact with the large number of individuals of T. granifera.

Astronotus ocellatus (Cichlidae: Pisces) and Macropodus opercularis (Anabatidae: Pisces) as predators of immature Aedes fluviatilis (Diptera: Culicidae) and Biomphalaria glabrata (Mollusca: Planorbidae)

Two fish species, Astronotus ocellatus (Cichlidae) and Macropodus opercularis (Anabatidae) were tested for predacious behavior toward immature mosquitoes (Aedes fluviatili9s, Diptera: Culicidae) and schistosomiasis snail hosts (Biomphalaria glabrata, Mollusca: Planorbidae), in the presence or absence of non-living food and laboratory conditions. A. ocellatus, a species indigenous to Brazil, was a very efficient predator of both organisms (alpha=1,05); M. operculatis, an exotic species, preyed well on immature mosquitoes, but small snails and snail egg-masses were ingested only irregulary. Both fish species seemed to prefer live to non-living food.

Observation on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid

Investigations were carried out on the host parasitoid interaction between Periplaneta americana, the American cockroach and Tetrastichus hagenowii, an oothecal parasitoid. This gregarious female parasitoid infected and or oviposited in only one host and caused 100 por cento mortality of the infected host. However, increase in parasitoid density decreased the progeny production and influenced the sex ratio. The progenies produced were male biased. When host preference was tested by offering oothecae of different species of cockroaches, T. hagenowii showed a predilection towards the oothecae of P. americana, suggestings its host specificity.

Bacillus sphaericus mosquito pathogens in the aquatic environment

The fate of Bacillus sphaericus spores in the aquatic environment was investigated by suspending spores in dialysis bags in fresh and seawater. Spore viability was lost more rapidly in seawater. Neither B. sphaericus nor B. thuringiensis israelensis (B.t.i.) spores mixed with pond sediment appeared to attach to the sediment. However, rapid decrease in B.t.i. toxicity suggested attachment of parasporal bodies to sediment. B. sphaericus toxin settled more slowly and less completely. B. sphaericus spores fed to larvae of four aquatic invertebrates were mostly eliminated from the animal gut in less than one week. An exception was the cranefly (Tipula abdominalis) where spores persisted in the posterior gut for up to five weeks.