Palpimanid spiders from Guyana: new species of the genera Fernandezina and Otiothops (Araneae, Palpimanidae, Otiothopinae)

Two new species of the spider family Palpimanidae from Guyana are described: Fernandezina takutu, the first species of this genus known from this country andOtiothops giralunas, that seems to be the sister species of O. goloboffi Grismado, 1996 from northwestern Argentina.

Description and ecological notes on Isoctenus malabaris sp. nov. (Araneae, Ctenidae) from southern Brazil

A new species, Isoctenus malabaris, is described from southern Brazil. This spider was abundantly collected with pitfall traps at Araucaria Forests (Mixed Ombrophilous Forest) domain. The activity of this species was studied in three distinct habitats (primary and secondary forests and silvicultures) during 20 months. A bimodal seasonal activity pattern, of males, was observed. Abundance differences of this species between habitats were not significant.

On the Neotropical genus Cybaeodamus (Araneae, Zodariidae, Storeninae)

Four new species of the spider genus Cybaeodamus Mello-Leitão, 1938 are described and illustrated: C. meridionalis sp. nov. from Brazil and Argentina, C. taim sp. nov. from Brazil, Argentina and Uruguay, C. brescoviti sp. nov. and C. tocantins sp. nov. from setentrional region of Brazil. For the species Cybaeodamus enigmaticus (Mello-Leitão, 1939), C. lycosoides (Nicolet, 1849) and C. ornatus Mello-Leitão, 1938, new illustrations based on the examination of the types are presented. The species Cybaeodamus nigrovittatus Mello-Leitão, 1941 which the holotype is an immature specimen, C. pallidus (Mello-Leitão, 1943) which the type was not located, C. rastellifer (Mello-Leitão, 1940) and C. scottae Mello-Leitão, 1941, both described upon juvenile specimens, all from Argentina, are considered as species inquirendae.

A new species of Tmesiphantes (Araneae, Theraphosidae) from the state of Pará, Brazil

A new species of Tmesiphantes Simon, 1892, T. aridai sp. nov., is described and illustrated based on three males and three females collected at the Floresta Nacional do Tapajós, Santarém, state of Pará, Brazil. Males can be distinguished from T. perp Guadanucci & Silva, 2012 by the palpal bulb with an inconspicous tegular basal projection, but presenting a very slender embolus with shorter keels not extending to the tip, and from T. nubilus Simon, 1892 by the tibial apophysis with two similarly sized branches, the prolateral one with a strong spine on the retrolateral margin. Females resemble T. nubilus by the aspect of the seminal receptacle but the constriction near the apex is less evident and apex shape is irregular. The new species represents the first record of Tmesiphantes from the Amazonian region, bringing the total number of species to eight.

Diversity, composition and phenology of araneid orb-weavers (Araneae, Araneidae) associated with riparian forests in southern Brazil

The Araneidae is a speciose family including web-spinning spiders that are very abundant in various terrestrial ecosystems. Several studies demonstrate that changes in vegetation surrounding rivers, streams and brooks affect the associated araneofauna. The aim of this research was to compare differences found in diversity (abundance and richness), composition and phenology of Araneidae spiders sampled in different habitats in four riparian forest catchments in southern Brazil. Samples were taken from riparian forests in four rivers of Rio Grande do Sul State: Piratini, Camaquã, Sinos and Maquiné rivers, each in a different hydrographic basin. Samples were taken twice seasonally on each basin during two years, sampling the araneofauna of the tree-shrub strata with beating tray. Six transects were employed on each basin, two per habitat: edge with grassland, forest interior and river edge. Araneids totalled 20 genera and 65 species. Comparing riparian forests significant differences are found. Spider abundance differed among riparian forests as well as species richness. Overall, Piratini river riparian forest had the higher abundance and richness for Araneidae; the lower values were in Sinos river forest. The stronger degradation and fragmentation of the riparian forests of Sinos river probably influenced the results, with human disturbance gradients associated negatively to web building. We present data on the diversity of these spiders, which were very abundant in the riparian forest interior and very rich in species in the grassland/riparian forest edge. Species composition also differs among the studied habitats (the above plus river/riparian forest edge). For the most abundant species the phenological pattern across the seasons was also analysed.

New species of Alpaida (Araneae, Araneidae) from Rondônia, Brazil

ABSTRACT We described a new species of spider, Alpaida clarindoi sp. nov. (Araneidae), from the southwestern Amazon forest. The new species is distinguished from most Alpaida by the presence of a pair of shoulders spines. Females can be separated from similar species by the subquadrangular shape of the epigynum, and males by the shape of the terminal apophysis and the tegulum, which possess an apical pointed tip. Alpaida clarindoi sp. nov. is described based on both sexes.

Hiperglicemia na intoxicação escorpiônica experimental em cão

The production of hyperglycemia during the acute phase of scorpion poisoning produced by T. bahiensis in dogs is confirmed now. The highest degree on average, was reached 10 minutes after the injection of venom. In our hands, the previous bilateral adrenalectomy did not avoid the hyperglycemia. The average of the blood sugar level has been similar to that observed in dogs with adrenal glands, the highest blood sugar level was also registered after 10 minutes. The hyperglycemia obtained in adrenolectomized dogs is, probably, due to the liberation of Sympatin (Nor-adrenalin and adrenalin) as a consequence of the central excitation by the poison on the hepatic nerves and other ganglionar terminations of the Sympathetic Nervous System. Our present researches suggest that the venom has adrenergic action besides the central action.

Estudo do mecanismo da hiperglicemia e da hipertensão arterial, produzidas pelo veneno de escorpião, no cão

In the present paper we studied the mechanism of the hyperglycemia and hypertension evoked by the intravenous injection of scorpion venom (Tityus bahiensis) in the dog. We used 34 dogs, of both sex, weighing between 4.3 to 22 kg. These animals were divided in 3 groups and the following experiments were performed: in the first group (8 dogs) the animals were adrenalectomized after the intravenous injection of chlorpromazine; in the second group (16 dogs) the animals were injected with ganglionic blocking drugs (9.295 Ciba and hexamethonium); in the third group (10 dogs) the naimals were injected with dibenamine, and in 3 of them the adrenal glands were removed. The dogs of each group were injected intravenously with aqueous extract of 2 telsons of scorpion/kg; the average weight of each telson was 6,5 mg. The following results were obtained: 1) The hyperglycemia evoked by scorpion venom, in adrenalectomized dogs, was inhibited by chlorpromazine; 2) Ganglionic blocking drugs (9.295 Ciba and hexamthonium) were inefective as far as the hyperglycemic and pressor effects of venom are concerned; 3) In the animals treated with dibenamine, the venom produced a fall in blood pressure, both in the controle and in the adrenalectomized. The present experiments suggest that the scorpion venom has, besides the central action already described by other investigators, an adrenergic action, very similar to the adrenaline. On basis of our experiments we think that the adrenergic action is responsible, in part, by the productrion of hyperglycemia and hypertension.

Factors underlying the natural resistance of animals against snake venoms

The existence of mammals and reptilia with a natural resistance to snake venoms is known since a long time. This fact has been subjected to the study by several research workers. Our experiments showed us that in the marsupial Didelphis marsupialis, a mammal highly resistant to the venom of Bothrops jararaca, and other Bothrops venoms, has a genetically origin protein, a alpha-1, acid glycoprotein, now highly purified, with protective action in mice against the jararaca snake venom.

Simian malaria at two sites in the Brazilian Amazon: I-The infection rates of Plasmodium brasilianum in non-human primates

The parasite that causes simian malaria in the Brazilian Amazon, Plasmodium brasilianum, is infective to man. In this region, where humans live within and in close proximity to the forest, it was suspected that this parasite could be the cause of a zoonosis. A study was performed in the areas surrounding two hydroelectric plants in the Amazon, Balbina and Samuel, aiming at determining the zoonotic potential of this parasite. P. brasilianum was detected in, respectively, 15.8% and 9.9% of 126 and 252 primates belonging to seven and eight species examined from Balbina and Samuel. The highest malaria infection rates were found among the red-howler monkey Alouatta seniculus straminea (32.3%), the bearded-saki Chiropotes satanas chiropotes (50%) and the spider-monkey Ateles paniscus paniscus (2[1+]) from Balbina and in the squirrel-monkey Saimiri ustus (21%) and the black-faced-spider-monkey Ateles paniscus chamek (28.6%) from Samuel.

Orius insidiosus (Say, 1832) (Heteroptera, Anthocoridae): sensibilidade ao fotoperíodo e diapausa reprodutiva?

The minute pirate bugs, Orius spp., are known as predators on several pests as thrips, aphids, spider mites and whiteflies. Orius insidiosus is an important thrips predator, commercially used around the world. However, one of the main problems on biological control of thrips in temperate regions is the occurrence of reproductive diapause in Orius species. This characteristic promotes the interruption of biological control strategies when predators are exposed to short photoperiods. This research had as objective to evaluate the influence of different photoperiod conditions on eggs/nymphs and adults of O. insidiosus in laboratory. The trials were carried out through the combination of eggs/nymphs and adults reared under the photoperiods 10L:14D; 11L:13D; 12L:12D and 13L:11D, at 25±2ºC and 70±10% RH. The predators were maintained during their pre-imaginal development time under one of the photoperiods and, after being emerged as adults transferred to another photoperiod regime. The predator had a tendency to present longer development time under photoperiod 13L:11D. There was no influence of the different photoperiods conditions on the reproduction of O. insidiosus. The females laid eggs normally during all their lifetime. O. insidiosus is not sensitive to photoperiod evaluated and do not enter in reproductive diapause.

Hymenoepimecis neotropica (Brues & Richardson) (Hymenoptera, Ichneumonidae, Pimplinae) parasitoid of Araneus omnicolor (Keyserling) (Araneae, Araneidae): first host record and new occurrence to Brazil

Hymenoepimecis neotropica (Brues & Richardson) (Hymenoptera, Ichneumonidae, Pimplinae) parasitoid of Araneus omnicolor (Keyserling) (Araneae, Araneidae): first host record and new occurrence to Brazil. The species of the genus Hymenoepimecis occur only in Neotropical region, being recognized for using as their hosts spiders which build orbicular webs. That wasp was described occurring only in the Guyana. This work expands the geographical distribution of the species to Brazil and records the spider Araneus omnicolor (Araneae, Araneidae) as its host. Furthermore, it provides information about the natural history of this interaction.

Screening of papaya accessions resistant to Papaya lethal yellowing virus and capacity of Tetranychus urticae to transmit the virus

The objective of this work was to produce a polyclonal antiserum against the coat protein (CP) of Papaya lethal yellowing virus (PLYV) and to determine its specificity and sensibility in the diagnosis of the virus, as well as to evaluate the genetic resistance to PLYV in papaya (Carica papaya) accessions and to investigate the capacity of the two-spotted spider mite Tetranychus urticae to acquire and transmit PLYV to the plants. Sixty-five papaya accessions were evaluated. For each accession, ten plants were mechanically inoculated using PLYV-infected plant extracts, and three plants were mock inoculated with phosphate buffer alone and used as negative controls. Ninety days after inoculation, newly-emerging systemic leaves were collected from the inoculated plants, and viral infection was diagnosed by indirect Elisa, using polyclonal antiserum sensible to the in vitro-expressed PLYV CP. Viral transmission by T. urticae was evaluated in greenhouse. The experiments were repeated twice. Polyclonal antiserum recognized the recombinant PLYV CP specifically and discriminated PLYV infection from infections caused by other plant viruses. Out of the 65 papaya accessions evaluated, 15 were considered resistant, 18 moderately resistant, and 32 susceptible. The two-spotted spider mite T. urticae was capable of acquiring PLYV, but not of transmitting it to papaya.

Constituintes químicos e atividade antiedematogênica de Peltodon radicans (Lamiaceae)

Most of the snakebite incidents in the Amazon region involve Bothrops atrox, whose venom presents the most potent edematogenic and necrotic activities in the genus. This work describes the studies of isolation of the chemical constituents and antiedematogenic activity of the species Peltodon radicans (Lamiaceae), which is used in the treatment of snakebites and scorpion stings in the region. The extracts presented aliphatic hydrocarbons, 3beta-OH,beta-amirin (1), 3beta-OH,alpha-amirin (2), beta-sitosterol (3), stigmasterol (4), ursolic acid (5), 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid (tormentic acid, 6), methyl 3beta-hydroxy,28-methyl-ursolate (7), sitosterol-3-O-beta-D-glucopyranoside (8), and stigmasterol-3-O-beta-D-glucopyranoside (9). The flower extracts presented the higher antiedematogenic activity. This is the first report on the study of the flowers, stem, and roots of this plant.

SEASONAL CHEMICAL COMPOSITIONS OF THE ESSENTIAL OILS OF TWOEugenia SPECIES AND THEIR ACARICIDAL PROPERTIES

The leaf essential oils of Eugenia lutescens Cambess andEugenia langsdorffii O. Berg, collected in the rainy (RS) and dry seasons (DS), were extracted by hydrodistillation and then characterized by a gas chromatography-flame ionization detector and a gas chromatography-mass spectrometer. The potential acaricidal activity and oviposition deterrence of these oils were evaluated against Tetranychus urticae . The oil yields were higher in the RS for E. lutescens, while those forE. langsdorffii were higher in the DS. α-Pinene and β-pinene were determined to be the major constituents of the oils fromE. lutescens, while bicyclogermacrene, spathulenol, and β-caryophyllene predominated in E. langsdorffii . Seasonal variations in the oils were primarily related to chemical diversity, and E. lutescens was more affected than was E. langsdorffii . The E. langsdorffii oil collected in the DS was most toxic to the spider mite, while the oils of E. lutescens and E. langsdorffii collected in the RS drastically reduced its egg quantities. This study successfully determined the periods of greater oil production and acaricidal activity.