New Brazilian spider mites (Acarina: Tetranychidae)

Seven species of spider mites namely, Tetranyohus (T.) paschoali Paschoal, 1970, Tetranyohus (T.) esoolastioae Paschoal, 1970, Tetranyohus (T.) zamithi Paschoal, 1970, Oligonyohus (0.) anonae Paschoal, 1970, Mononyohus bondari Paschoal, 1970, Mononyohus ohemosetosus Paschoal, 1970, and Allonyohus reisi Paschoal, 1970, are described. The male allotype of Allonychus braziliensis (McGregor, 1950) is described and the female redescribed. These species were described as new in a thesis submited to Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Brazil, on June 13, 1970.

Studies on the mineral nutrition and fertilization of the passion fruit plant (Passiflora edulis f. flavicarpa): II - placement of fertilizer phosphorus

A localização do superfosfato (marcado com P32) no maracujá em produção foi estudada em condições de plantação comercial. Verificou-se que as aplicações em sulcos circulares ou faixas superficiais ao redor da planta tem eficiência equivalente sendo esses métodos três vezes superiores à localização do adubo em furos no solo. A pulverização foliar, por sua vez, mostrou-se 20 vezes mais eficiente que a aplicação no solo de acordo com os dois primeiros métodos.

Studies on the mineral nutrition and fertilization of the passion fruit plant (Passiflora edulis F. flavicarpa): II. placement of fertilizer phosphorus

1. Tagged superphosphate was applied to 2.5 year old passion fruit plants from a commercial plantation established in a sandy loam. 2. 100 grams of the fertilizer were distributed in the following ways: in a circular furrow 20 cm around the plant 40 cm from the stems; in a circular strip 10 cm wide, 40 cm from the stems; in six holes around the plants, 40 cm from the stems 20 cm deep, 2.5 cm in diameter. 3. 10 grams of the fertilizer in 11 of water were sprayed to the leaves. 4. Three weeks after the treatments were made, leaf samples were taken for analysis. 5. Determinations of specific activities both in the leaves and in the fertilizer used have shown that R in the plant was derived from the superphosphate in the following relative proportions (by making the first treatment equal to 100): circular furrow = 100; circular strip = 120; holes = 30; foliar spray = 230.

Stink bugs (Heteroptera, Pentatomidae) and an unique host plant in the Brazilian subtropics

Stink bugs are seed/fruit sucking insects feeding on an array of host plants. Among them, an exotic tree called privet, Ligustrum lucidum Ait. (Oleaceae), is very common in the urban areas of the Brazilian subtropics, where it is utilized as food source and shelter for over a decem species of bugs, year round. The species composition, their performance and abundance on this host, and possible causes for this association are discussed and illustrated.

Impact of a power plant cooling system on copepod and meroplankton survival (Bahía Blanca estuary, Argentina)

The impact of a power plant cooling system in the Bahía Blanca estuary (Argentina) on the survival of target zooplanktonic organisms (copepods and crustacean larvae) and on overall mesozooplankton abundance was evaluated over time. Mortality rates were calculated for juveniles and adults of four key species in the estuary: Acartia tonsa Dana, 1849 and Eurytemora americana Williams, 1906 (native and invading copepods), and larvae of the crab Chasmagnathus granulata Dana, 1851 and the invading cirriped Balanus glandula Darwin, 1854. Mean total mortality values were up to four times higher at the water discharge site than at intake, though for all four species, significant differences were only registered in post-capture mortality. The findings show no evidence of greater larval sensitivity. As expected, the sharpest decrease in overall mesozooplankton abundance was found in areas close to heated water discharge.

Geographic variation in ectoparasitic mites diversity in Tadarida Brasiliensis (Chiroptera, Molossidae)

Tadarida brasiliensis (Geoffroy, 1824), the Brazilian free-tailed bat, is an insectivorous bat that occurs from southern United States of America to southern South America. In this study we present the first data on diversity of ectoparasitic mites of T. brasiliensis in Brazil. A compilation and analysis of the studies of mite diversity conducted in different points the geographic distribution this bat species are provided. The mites were collected from March 2010 to November 2011 on 160 T. brasiliensis adult bats captured in southern Brazil. Four species of mites have been found: Chiroptonyssus robustipes (Ewing, 1925), Ewingana longa (Ewing, 1938), Ewingana inaequalis (Radford, 1948), and specimens of Cheyletidae. Chiroptonyssus robustipes was the most prevalent species (100%), followed by E. longa (20%), E. inaequalis (10%), and specimens of Cheyletidae (1.25%). The data currently available show that C. robustipes parasitizes T. brasiliensis throughout its region of occurrence, and this mite is highly prevalent and abundant. The two species of Ewingana accompany the geographical distribution of T. brasiliensis, but with much lower prevalence and abundance.

Molluscicide activity of the "Avelós" plant (Euphorbia tirucalli, L. ) on Biomphalaria glabrata, the mollusc vector of schistosomiasis

An aqueous solution of the latex of Euphorbia tirucalli collected at sites receiving large amounts of sunlight showed molluscicide action on Biomphalaria glabrata, with LD50 obtained at the concentration of 28,0 ppm and LD90 at the concentration of 85,0 ppm. The toxicity of the product for fish was similar to that of Bayluscide and of copper sulfate used for comparison. However, the wide distribution of the plant, its easy propagation and the simple procedure for extraction of the active substance, which is biodegradable, favor "avelós" as a promising agent in the control of schistosomiasis.

The role of behavior in the survival of Biomphalaria glabrata in biossays with the plant molluscicide Phytolacca dodecandra

This work examines the role of behavior in the survival of Biomphalaria glabrata exposed to 25, 50 75 and 100 mgl-1 of Phytolacca dodecandra. Time-lapse cinematography was used to quantify accurately the following parameters: (a) frequency of exits from the solution, (b) time spent out of the solution and (c) time elapsed until the first exit from the solution. These behavior patterns were statistically compared between surviving snails and those which later died. The proportion of surviving snails leaving the liquid medium was significantly higher than that of dying snails. In addition, the surviving group spent significantly more time out of the solution than the group which died, except for the 100 mgl-1 concentration. However, no significant difference was detected in the time elapsed until the first exit from the solution. It can be concluded that both the tendency to leave the P. dodecandra solutions, and the time spent out of them, contributed significantly to snail survival. Molluscicide bioassays should take into account the possibility that some behavior patterns of planorbids might contribute to the protection of the snails.

Influence of several plant extracts on the oviposition behaviour of Aedes fluviatilis (Lutz) (Diptera: Culicidae) in the laboratory

Whole, ethanolic, hexanic, lyophilized extracts of several plants and anacardic acid tested in respect of their influence on the oviposition behavior of Aedes fluviatilis (Lutz) at 100, 10 and 1 ppm concentrations. Extracts of Allium stivum, Jatropha curcas, Mikania schenkii, Poinciana regia and Spatodea campanulata had a repulsive effect (α=0.05) on females at 100 ppm, those of Anacardium occidentale, Bidens segetum and Caesalpinia peltophoroides were also repelent at 10 ppm. Extracts of Coriandrum sativum (100, 10 and 1 ppm), Chara Zeylanica (10 ppm), Cupressus sempervirens (10 ppm), Foeniculum vulgare (10 ppm) and Spatodea campanulata (1 ppm) were attractive to the females; 13 (52.0%) of the extracts tested, did not influence the oviposition behavior.

Plant tissue culture techniques

Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus) or organized tissues or organs put in culture, under controlled sterile conditions.

Genotoxicity of plant extracts

Aqueous extracts of seven species used in Brazilian popular medicine (Achyrocline satureoides, Iodina rhombifolia, Desmodium incanum, Baccharis anomala, Tibouchina asperior, Luehea divaricata, Maytenus ilicifolia) were screened to the presence of mutagenic activity in the Ames test (Salmonella/microsome). Positive results were obtained for A. satureoides, B anomala and L. divaricata with microsomal activation. As shown elsewhere (Vargas et al., 1990) the metabolites of A. satureoides extract also show the capacity to induce prophage and/or SOS response in microscreen phage induction assay and SOS spot chromotest.

Plant lectins, chemical and biological aspects

Lectins, carbohydrate-binding proteins of non-immune origin, that agglutinate cells or precipitate polysaccharides and glycoconjugates, are well distributed in nature, mainly in the Plant Kingdom. The great majority of the plante lectins are present in seed cotyledons where they are found in the cytoplasm or int he protein bodies, although they have also been found in roots, stems and leaves. Due to their peculiar properties, the lectins are used as a tool both for analytical and preparative purposes in biochemistry, cellular biology, immunology and related areas. In agriculture and medicine the use of lectins greatly improved in the last few years. The lextins, with few exceptions, are glycoproteins, need divalent cations to display full activity and are, in general, oligomers with variable molecular weight. Although the studies on lectins have completed a century, their role in nature is yet ynknown . Several hypotheses on their physiological functions have been suggested. Thus, lectins could play important roles in defense against pathogens, plant-microorganism symbiosis, cell organization, embryo morphogenesis, phagocytosis, cell wall elongation, pollen recognition and as reserve proteins. A brief review on the general properties and roles of the lectins is given.

Preliminary investigations on transmission and life cycle of the ear mites of the genus Raillietia trouessart (Acari: Gamasida) parasites of cattle

The life cycle of ear mites of the genus Raillietia Trouessart consists of egg, larva, proto-and deutonymph and adult. The proto-and deutonymph are free living, non feeding instars. The teneral adult is the transfer stage. The minimum period required for completion of the life cycle is approximately eight days.

Forest culicinae mosquitoes in the environs of samuel hydroeletric plant, state of Rondônia, Brazil

Data on frequency and seasonal distribution of culicinae were recorded in the forest near a recently constructed hydroelectric plant - Samuel, in the State of Rondônia, Brazilian Amazon. Collections were performed almost daily from August 1990 to July 1991, between 6 and 9 p.m., using human bait. A total of 3,769 mosquitoes was collected, representing 21 species, including seven new records for the State of Rondônia. The most frequently collected species were Aedes fulvus (25%) and Ae. pennai (12.3%). The highest density for the majority of mosquito species coincided with the rainy season.

Screening of Asteraceae (Compositae) Plant Extracts for Larvicidal Activity against Aedes fluviatilis (Diptera: Culicidae)

Ethanol extracts of 83 plants species belonging to the Asteraceae (Compositae) family, collected in the State of Minas Gerais, Brazil, were tested for larvicidal activity against the mosquito Aedes fluviatilis - Diptera: Culicidae). The extract from Tagetes minuta was the most active with a LC90 of 1.5 mg/l and LC50 of 1.0 mg/l. This plant has been the object of several studies by other groups and its active components have already been identified as thiophene derivatives, a class of compounds present in many Asteraceae species. The extract of Eclipta paniculata was also significantly active, with a LC90 of 17.2 mg/l and LC50 of 3.3 mg/l and no previous studies on its larvicidal activity or chemical composition could be found in the literature. Extracts of Achryrocline satureoides, Gnaphalium spicatum, Senecio brasiliensis, Trixis vauthieri, Tagetes patula and Vernonia ammophila were less active, killing more than 50% of the larvae only at the higher dose tested (100 mg/l).