Vector bionomics and malaria transmission in the Upper Orinoco River, Southern Venezuela

A longitudinal epidemiological and entomological study was carried out in Ocamo, Upper Orinoco River, between January 1994 and February 1995 to understand the dynamics of malaria transmission in this area. Malaria transmission occurs throughout the year with a peak in June at the beginning of the rainy season. The Annual Parasite Index was 1,279 per 1,000 populations at risk. Plasmodium falciparum infections accounted for 64% of all infections, P. vivax for 28%, and P. malariae for 4%. Mixed P. falciparum/P. vivax infections were diagnosed in 15 people representing 4% of total cases. Children under 10 years accounted for 58% of the cases; the risk for malaria in this age group was 77% higher than for those in the greater than 50 years age group. Anopheles darlingi was the predominant anopheline species landing on humans indoors with a biting peak between midnight and dawn. A significant positive correlation was found between malaria monthly incidence and mean number of An. darlingi caught. There was not a significant relationship between mean number of An. darlingi and rainfall or between incidence and rainfall. A total of 7295 anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite (CS) protein. Only An. darlingi (55) was positive for CS proteins of P. falciparum (0.42%), P. malariae (0.25%), and P. vivax-247 (0.1%). The overall estimated entomological inoculation rate was 129 positive bites/person/year. The present study was the first longitudinal entomological and epidemiological study conducted in this area and set up the basic ground for subsequent intervention with insecticide-treated nets.

Anopheles darlingi bionomics and transmission of Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae in Amerindian villages of the Upper-Maroni Amazonian forest, French Guiana

French Guiana is one of the areas in South America most affected by malaria and where the disease has become a serious public health problem. In spite of this situation, little recent entomological data are available from the main localities where the disease occurs, even though they are crucial for development of an effective vector control strategy. A longitudinal entomological survey was carried out from March 2000-February 2002 in three Amerindian villages, namely Twenké, Taluène and Cayodé, located in the Amazonian forest of the Upper-Maroni area, to assess anopheline mosquitoes and malaria transmission dynamics. Anopheles darlingi (Diptera: Culicidae) was the most abundant mosquito species caught during the study. This efficient American malaria vector was active the entire year, but showed an evident peak of abundance during the main rainfall season, from April-June, with an average human biting rate of 255.5 bites per person per night. Parity rates were homogeneous all year, indicating no significant seasonal variability in female survival rates. Estimated vectorial capacity indices were higher during the rainy season, even though the risk of transmission was present throughout the year (VCI > 1). A total of 14 An. darlingi were found infected with Plasmodium falciparum, Plasmodium vivax or Plasmodium malariae. The annual circumsporozoite indices were 0.15, 0.14 and 0.05, and the entomological inoculation rates were 22.8, 27.4 and 14.4 infected bites per person per year in Twenké, Taluène and Cayodé, respectively. An. darlingiwas endo-exophagic and rather exophilic in these localities. The species was collected throughout the night but was more aggressive between 21:30-03:30 h and after 05:30 h. Parity rates were homogeneous during the entire night. Impregnated hammock and/or bed nets, coupled with the use of mosquito repellents, as well as the early treatment of malarial cases, appear to be the most suitable tools for fighting malaria in these Amerindian villages since the spraying of residual insecticides is inefficient because of vector biology and the housing structure.

Ecology of Haemagogus sp. and Sabethes sp. (Diptera: Culicidae) in relation to the microclimates of the Caxiuanã National Forest, Pará, Brazil

This study was conducted in a meteorological tower located in the Caxiuanã Forest (municipality of Melgaço, Pará, Brazil) with the aim of assessing the vertical stratification of species of Haemagogus and Sabethes, potential vectors of the yellow fever virus. To investigate the role of microclimates in mosquito stratification, bimonthly collections were conducted at ground level (0 m), 8 m, 16 m and 30 m (canopy level), with the aid of entomological nets and suction tubes, from July 2005-April 2006. A total of 25,498 mosquitoes were collected; specimens of Sabethes sp. and Haemagogus janthinomyswere found mostly at heights of 16 m and 30 m while Hg. leucocelaenus was most frequently observed at ground level. The largest number of vector species was collected during the rainiest months, but this difference between seasons was not statistically significant. However, the number of Hg. janthinomys was positively correlated with variations in temperature and relative humidity.

Can Wolbachia be used to control malaria?

Malaria is a mosquito-borne infectious disease caused by Plasmodium parasites transmitted by the infectious bite of Anopheles mosquitoes. Vector control of malaria has predominantly focused on targeting the adult mosquito through insecticides and bed nets. However, current vector control methods are often not sustainable for long periods so alternative methods are needed. A novel biocontrol approach for mosquito-borne diseases has recently been proposed, it uses maternally inherited endosymbiotic Wolbachia bacteria transinfected into mosquitoes in order to interfere with pathogen transmission. Transinfected Wolbachia strains in Aedes aegypti mosquitoes, the primary vector of dengue fever, directly inhibit pathogen replication, including Plasmodium gallinaceum, and also affect mosquito reproduction to allow Wolbachia to spread through mosquito populations. In addition, transient Wolbachia infections in Anopheles gambiae significantly reduce Plasmodium levels. Here we review the prospects of using a Wolbachia-based approach to reduce human malaria transmission through transinfection of Anopheles mosquitoes.

The behaviour of mosquitoes in relation to humans under holed bednets: the evidence from experimental huts

The physical integrity of bednets is a concern of national malaria control programs, as it is a key factor in determining the rate of replacement of bednets. It is largely assumed that increased numbers of holes will result in a loss of protection of sleepers from potentially infective bites. Experimental hut studies are valuable in understanding mosquito behaviour indoors, particularly as it relates to blood feeding and mortality. This review summarises findings from experimental hut studies, focusing on two issues: (i) the effect of different numbers or sizes of holes in bednets and (ii) feeding behaviour and mortality with holed nets as compared with unholed nets. As might be expected, increasing numbers and area of holes resulted in increased blood feeding by mosquitoes on sleepers. However, the presence of holes did not generally have a large effect on the mortality of mosquitoes. Successfully entering a holed mosquito net does not necessarily mean that mosquitoes spend less time in contact with the net, which could explain the lack in differences in mortality. Further behavioural studies are necessary to understand mosquito behaviour around nets and the importance of holed nets on malaria transmission.

As abelhas eussociais (Hymenoptera, Apidae) visitantes florais em um ecossistema de dunas continentais no médio Rio São Francisco, Bahia, Brasil

Highly eusocial bees (Hymenoptera, Apidae) flower visitors in a continental sand dune ecosystem from the medium São Francisco River, Bahia, Brazil. A community of highly eusocial bees in sand dunes, covered with caatinga vegetation, in the medium São Francisco River, Bahia (10º47' 37"S and 42º49' 25"W) was studied. The local climate is semi arid and hot, with mean temperature of 25.7 ºC and annual precipitation of 653.8 mm. Censuses took place every two months, from February to December of 2000. The bees were sampled on flowers with entomological nets, from 6:00 a.m. to 5:00 p.m. A total of 2,147 individuals of eight species of Apinae were found, of which Apis mellifera Linnaeus (40.2%), Trigona spinipes (Fabricius) (28.7%) and Frieseomelitta silvestri languida Moure (14.7%) were the predominant species. The diversity was H' = 1.53 and the evenness E' = 0.73. The bees were active during the whole year, but there was a significant variation in the monthly abundance of individuals (c2= 799.55; df= 35; p<0.0001). The daily activity was greater between 6:00 a.m. and 8:00 a.m. The low bee diversity observed is a consequence of the low richness of botanical species and of the small amount of sites for the bees' nests. The community of highly eusocial bees from the dunes presents organization patterns similar to those observed in other caatinga areas, albeit with some particularities.

Butterflies (Lepidoptera, Papilionoidea and Hesperioidea) of the "Baixada Santista" region, coastal São Paulo, southeastern Brazil

Butterflies (Lepidoptera, Papilionoidea and Hesperioidea) of the "Baixada Santista" region, coastal São Paulo, southeastern Brazil. A list with 538 species of butterflies recorded in the Baixada Santista, São Paulo ( SE Brazil) is presented. Standard sampling protocols (i.e. with entomological nets) were followed. Baited traps were installed for fruit feeding species. Data from the literature and entomological collections were also considered in the total estimated species richness. The species richness recorded in the Baixada Santista region represents about 16% of the Brazilian butterfly fauna, and 34% of the known butterfly fauna for the state of São Paulo. The present list contains an appreciably higher number of species in comparison to other lists from similar biomes farther south, such as Blumenau in Santa Catarina, and Maquiné in Rio Grande do Sul.

Diversity of the euglossine bee community (Hymenoptera, Apidae) of an Atlantic Forest remnant in southeastern Brazil

Diversity of the euglossine bee community (Hymenoptera, Apidae) of an Atlantic Forest remnant in southeastern Brazil. Euglossine bees, attracted to scent baits of cineole, eugenol and vanillin, were collected with entomological nets, from December 1998 to November 1999. Samplings were carried out once a month simultaneously by two collectors positioned in two different sites in an Atlantic Forest remnant in northeastern São Paulo state, Brazil. A total of 859 male euglossine bees, belonging to 13 species and four Euglossini genera were collected. Of the total sample, 506 (12 species) males were captured at site A and 353 (10 species) were collected at site B.In both sites, Euglossa pleosticta Dressler, 1982 was the most abundant species (45.79%), followed by Eulaema nigrita Lepeletier, 1841 (20.79%). The results of this study supply new information about the diversity of orchid bee fauna in Atlantic Forest remnants as well as show that more than one site is needed to sample these bees in a fragmented landascape.

Diversity of Ephemeroptera (Insecta) of the Serra da Mantiqueira and Serra do Mar, southeastern Brazil

The aim of this study was to inventory the mayfly fauna, based on nymphal and alate stages, in Serra da Mantiqueira and in Serra do Mar, São Paulo State, as well as to present information about habitats used by the genera. Nymphs were collected in several streams and mesohabitats with a Surber sampler and the winged stages with light attraction methods, entomological nets, and Malaise traps. In all, eight families and 33 genera were recorded, representing a very significant portion of the Brazilian fauna (80% of families and 49% of genera). Furthermore, it was possible to identify 11 species, of which two are new records for the state: Tricorythodes santarita Traver and Caenis reissi Malzacher. Despite the high diversity recorded, the accumulation curves presented an ascending form, indicating an increase in the number of genera with additional sampling effort. The high richness found in these areas are in agreement with the high biodiversity of the Atlantic Forest biome and the sampling effort employed, which included the use of different methods, the collection of both nymphs and winged stages, and the sampling of a large area with diverse streams and habitats.

When rare is just a matter of sampling: unexpected dominance of clubtail dragonflies (Odonata, Gomphidae) through different collecting methods at Parque Nacional da Serra do Cipó, Minas Gerais State, Brazil

When rare is just a matter of sampling: Unexpected dominance of clubtail dragonflies (Odonata, Gomphidae) through different collecting methods at Parque Nacional da Serra do Cipó, Minas Gerais State, Brazil. Capture of dragonfly adults during two short expeditions to Parque Nacional da Serra do Cipó, Minas Gerais State, using three distinct collecting methodsaerial nets, Malaise and light sheet trapsis reported. The results are outstanding due the high number of species of Gomphidae (7 out of 26 Odonata species), including a new species of Cyanogomphus Selys, 1873, obtained by two non-traditional collecting methods. Because active collecting with aerial nets is the standard approach for dragonfly inventories, we discuss some aspects of the use of traps, comparing our results with those in the literature, suggesting they should be used as complementary methods in faunistic studies. Furthermore, Zonophora campanulata annulata Belle, 1983 is recorded for the first time from Minas Gerais State and taxonomic notes about Phyllogomphoides regularis (Selys, 1873) and Progomphus complicatus Selys, 1854 are also given.

Preliminary study of insects associated to indoor body decay in Colombia

Preliminary study of insects associated to indoor body decay in Colombia. This is the first report studying insects associated to indoor body decay process of a white pig (Sus scrofa) (Artiodactyla, Suidae) in a controlled indoor environment in an urban area of Florencia city, Amazonia Piedmont, Colombia. For a period of 54 days, 9,220 individuals (immature and adults), distributed in 3 orders, 5 families, 10 genera, and 10 species were collected using entomological nets and tweezers. Five decaying stages are described (fresh, bloated, active decay, advanced decay and remains). During the fresh stage we recorded Cochliomyia macellaria (Fabricius, 1775), Chrysomya albiceps (Wiedemann, 1819), Ophyra aenescens (Wiedemann, 1830), Oxysarcodexia sp., Lepidodexia sp. and Lasiophanes sp.; during the bloating stage C. macellaria, C. albiceps, Lucilia eximia (Wiedemann, 1819), Hemilucillia semidiaphana (Rondani, 1850), Musca domestica Linnaeus, 1758, O. aenescens, Oxysarcodexia sp., Lepidodexia sp., Dermestes maculatus De Geer, 1774 and Lasiphanes sp.; during the active decay C. macellaria, C. albiceps, L. eximia, M. domestica, O. aenescens, Lepidodexia sp. D. maculatus and Lasiophanes sp.; during the advanced decay C. macellaria, C. albiceps, M. domestica, Lepidodexia sp. and Lasiophanes sp.; and during the remains stage C. albiceps, D. maculatus and Lasiophanes sp. The insects were sorted out in 3 ecological categories; necrophagous, predators and parasites and sarco-saprophagous. According to Chao and Jack estimators, total richness was observed on day 20, with 100% of the expected species.

Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest

Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest. The knowledge of social wasp richness and biology in the Amazonian region is considered insufficient. Although the Amazonas state is the largest in the region, until now only two brief surveys were conducted there. Considering that the systematic inventory of an area is the first step towards its conservation and wise use, this study presents faunal data on social wasp diversity in a 25 km² area of "terra firme" (upland forest) at the Ducke Reserve, Manaus, Amazonas, Brazil. Wasps were collected in the understory, following a protocol of three collectors walking along 60 trails 1,000 m in extension for 16 days between August and October 2010. Methods used were active search of individuals with entomological nets and nest collecting. Fifty-eight species of social wasps, allocated in 13 genera, were recorded; 67% of the collected species belong to Polybia, Agelaia and Mischocyttarus; other genera were represented by only four species or less. The most frequent species in active searches were Agelaia fulvofasciata (DeGeer, 1773), Agelaia testacea (Fabricius, 1804) and Angiopolybia pallens (Lepeletier, 1836). Twelve species were collected in nests. Prior to this study, 65 Polistinae species were deposited at the INPA Collection. Collecting in the study grid, an area not previously sampled for wasps, resulted in an increase of 25% species, and species richness was 86. According to the results, there is evidence that the diversity of social wasps at the Ducke Reserve is even higher, making it one of the richest areas in the Brazilian Amazonia.

Hypatropis inermis (Hemiptera, Pentatomidae): first record on rice crops

This study reports for the first time the occurrence of Hypatropis inermis on upland rice crops (variety Cambará), in Novo Progresso, state of Pará, Brazil (7°07'45.71"S 55°23'21.13"W). The inventory of insect pests was conducted between November 2010 and March 2011 with entomological sweep nets and visual search on stems of rice plants. This record indicates that rice crops may represent important feeding and mating sites for this species.

Estudo analítico sôbre Nephrops rubellus Moreira (Crustáceo - Decapodo - Macruro)

O presente trabalho tem por objetivo registrar a ocorrência de um Crustáceo denominado "Lagostim" - Nephrops rubellus MOREIRA, em águas das cercanias da Ilha Xavier, situada no litoral do Estado de Santa Catarina. O espécime foi capturado em rede "trawl", pelo barco de pesca "Libertador" a uma profundidade de 30 a 60 braças, em meados de junho de 1950. A espécie, que foi descrita em 1903 por CARLOS MOREIRA, parece não ser das mais comuns no litoral brasileiro, tendo sido, contudo, assinalada a sua presença no litoral argentino, por DOELLO JURADO, em 1938. O presente trabalho parece justificar-se por se tratar de um Crustáceo apenas referido na nossa literatura especializada há cerca de meio século e também por não concordarem totalmente os caracteres do exemplar em apreço com os do anteriormente descrito. Foi elaborada uma chave para o gênero Nephrops, destinada a determinar as espécies atlânticas e indo-pacíficas, tendo sido tomado como ponto de partida a chave organizada por DE MAN.

Hydrozoa e Scyphozoa existentes no instituto paulista de oceanografia

Continuing the inventory of the Coelenterate Fauna of the Brazilian coast, 23 species of Hydrozoa and a Scyphomedusa are recorded from different points of the coast aproximately between 22º and 24º lat. S. Of these, 14 species were already known from other points of the coast and the remaining 10 were unknown from this latitude. Two species are here listed as new, they are: Halocordyle fragHis and Calicella gabriellae. 1. - Halocordyle fragilis, Stechow's (1923) correction of the generic name Pennaria has been followed, shows remarkable distinctive specific characters such as: alternate distribution of the cladii which do not lie all in the same plane, they are inserted at random on the hydrocaulus with a tendency towards a spiral dexiotropic distribution, sparse distribution of the pedicels which are alternate and not all located on the same side of the hydrocladium, and, finally, the long, wiry aspect of the colony which is as brittle as light glass. This characteristics are not sufficient, to my belief, to establish a new genus, since the polyps and the gonophores are entirely of the Halocordyle type, but they confer upon the species a very peculiar habitus. 2. - Calicella gabriellae forms erect hydrocauli which are extremely soft and flexuose, with hydrothecate and intermediate internodes. The thecae are deep, cylindrical, with a conical base, there are 10-12 long and narrow opercular valves. The gonangia are small, conical, with a short distal digitiform process. The included sporosac exhibits maturing ova. Dynamena heteroclonta described by Jarvis (1922) as a new species, is here considered as a new form of the very variable species Dynamena quadridentata. Schizotricha billardi nom. nov., is specifically separated from Sch. diaphana (Heller) to which it had been identified up to know. The Brazilian colonies agree with the French Somaliland specimens described by Billard (1904) and they are reunited in a new species named after the French worker. The main difference, between the two mentioned species are: shape and size of the gonothecae, of the thecae and of the nematophores. A description is given of all the species not previously recorded from the Brazilian coast as well as biological observations on Olindias sambaquiensis whose shoals during winter months are very large and may entangle partially the fishermen's nets. Its feeding and swimming habits are described and the species proves to be an excellent laboratory animal both for class and research purposes, for it easily endures long transportation (even up to 12 hours during summer months) as well as unoxygenized acquaria and nevertheless greadily feeds on any animal food.