Epidemiology of snake envenomation from Mato Grosso do Sul,Brazil

Snake envenomation is considered a public health problem in tropical countries, where they occur in a high incidence. The present study reports the snake envenomation that occurred in Mato Grosso do Sul state (Brazil) between 2007 and 2017. Epidemiological data were obtained from the online platform of the Notification Disease Information System and were analyzed according to biome. A total of 5568 cases of snake envenomations were recorded during the study period, where the highest frequency was registered between October and April. The majority of envenomations occurred in working-age males (20 to 39 years), caused mainly by Bothrops snakes, and the duration of care after the envenomation in most cases took three hours. The municipalities that showed the highest snake envenomations case per 100,000 inhabitants presents low population density, and have their economy based on agricultural activity, which is a risk factor to snake envenomations. To the Mato Grosso do Sul state, the total number of snake envenomations had a positive relationship with the size of the municipality. Since this, larger areas usually have a mosaic of environments, which may harbor higher richness and abundance of snakes, and can cause more snake encounters with the population, resulting in more snake envenomations.     

Feral pigs as hosts for Amblyomma sculptum (Acari: Ixodidae) populations in the Pantanal,Mato Grosso do Sul,Brazil

The Pantanal in Brazil is the largest floodplain of the world. This ecosystem, rich in wildlife, has a large feral pig population. Such a large host biomass must have a strong influence on the parasite fauna. In this work, we evaluated the role of feral pigs in the maintenance of Amblyomma sculptum (formerly Amblyomma cajennense), the most prevalent tick species in the Pantanal. Tick infestations were evaluated on 243 feral pigs and their environment. The suitability of domestic pigs, representing their feral relatives, to A. sculptum adults and nymphs was assessed experimentally. Tick infestation of feral pigs was strongly associated with that of the environment: 96 and 97 % of the ticks, respectively, were A. sculptum. The infestation prevalence on this host species was close to 90 % in the dry season and 100 % in the wet season and mean infestation intensity was above 30 ticks in both seasons. Suitability of pigs as hosts for A. sculptum was shown by the high proportion of nymphs and female ticks found engorging on captured feral pigs and adequate biological parameters displayed by ticks from experimental infestations of domestic pigs. Other tick species on feral pigs, albeit in much lower numbers, were Amblyomma parvum and Ornithodorus rostratus. Results show that feral pigs feed a high proportion of the A. sculptum adults and nymphs in their territories and should be a target for tick-borne diseases studies. This is particularly relevant to public health because all the main tick species found on feral pigs are aggressive to humans as well.     

Effect of entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae)

This study aimed to evaluate the effect of commercially used entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae). Four bioassays were performed: 1) pulverized entomopathogens on A. mellifera; 2) entomopathogens sprayed on a smooth surface; 3) entomopathogens sprayed on soy leaves; and 4) entomopathogens mixed with candy paste (sugar syrup). Five treatments were prepared: sterile distilled water (control), distilled water sterilized with Tween^® 80 (0.01%), and the commercial entomopathogens Metarhizium anisopliae E9 (1.0 × 10⁹ conidia mL^?1), Beauveria bassiana PL63 (1.0 × 10⁸ conidia mL^?1) and Bacillus thuringiensis var. kurstaki HD-1 (3.0 × 10⁸ spores mL^?1). Each treatment consisted of five repetitions, with 20 workers per repetition, which were stored in a plastic box and, later, in a biological oxygen demand (B.O.D.) incubator (27 ± 2 °C, RH of 60% ± 10%, 12-h photophase). The mortality of the workers was evaluated from 1 h to 240 h, and the data were analyzed using Bayesian inference. The workers killed by the ingestion of candy paste contaminated with the pathogens (products) were randomly separated and selected for the removal of the midgut. Each midgut was fixed in Bouin's solution and prepared for histology. B. bassiana was verified to reduce the survival of A. mellifera workers in all bioassays. Moreover, M. anisopliae reduced the survival of A. mellifera workers directly sprayed, on a smooth surface and mixed with candy. B. thuringiensis reduced A. mellifera survival on a smooth surface and mixed with candy paste. However, its effects were lower than that observed by B. bassiana. The treatments with the biological products did not induce morphometric alterations in the midgut of A. mellifera.     

Occurrence of Panstrongylus guentheri Berg (Hemiptera: Reduviidae) in Mato Grosso do Sul State, Brazil

The first occurrence of Panstrongylus guentheri Berg in Brazil is presented. This species had been reported only in the territories of Argentina, Paraguay, Bolivia and Uruguay. We have extended the geographic distribution of this Triatominae, with two specimens captured in Bodoquena and Itapor? cities, both in Mato Grosso do Sul State, Brazil. These specimens were found in the intradomestic environment.     

Microsatellite Polymorphisms in Cassava Landraces from the Cerrado Biome, Mato Grosso do Sul, Brazil

Using nine microsatellite loci, we investigated genetic structure and diversity in 83 Brazilian cassava accessions, including several landraces, in the Cerrado biome in Mato Grosso do Sul, Brazil. All nine loci were polymorphic, averaging 6.00 alleles per locus. Treating each of seven municipalities as a cassava group or population, they averaged 3.5 alleles per locus, with 97% polymorphic loci, high values for observed heterozygosity (0.32) and gene diversity (0.56). Total genetic variability was high (0.668), and most of this genetic variability was concentrated within municipalities (0.577). Cluster and structure analyses divided accessions into two major clusters or populations (K = 2). Also, a significant genetic versus geographic correlation was found (r = 0.4567; P < 0.0260). Migratory routes in the Cerrado are considered main contributors to the region’s high cassava diversity and spatial genetic structure, amplifying interactions between traditional farmers and the evolutionary dynamics of this crop.     

Kinetic properties of arginine phosphokinase from honeybees, Apis mellifera L. (Hymenoptera, Apidae)

The kinetic properties of honeybee arginine phosphokinase (APK), which catalyzes the reaction: Arginine phosphate + ADP + H⁺ ? arginine + ATP, have been studied.In the direction of ATP synthesis, the pH optimum was around pH 7.2 and the activation energy over the range 18–44 °C was about 10,500 cal/mole. The optimum ratio of Mg²⁺:ADP was about 4:1.In the direction of arginine phosphate (AP) synthesis, the enzyme had a pH optimum around pH 8.3. The energy of activation for the reaction over the range 22–39 °C was about 7500 cal/mole. The optimum ratio of Mg²⁺:ATP was about 1:1.The initial velocities of the reactions in the direction of ATP and AP synthesis were measured at varying concentrations of one substrate while the concentration of the other substrate was held constant at several levels. The double reciprocal plots of the data obtained yielded a series of intersecting lines, indicating that the enzyme has a sequential mechanism. Radioisotope exchange experiment showed that arginine phosphokinase did not catalyze ATP ? ADP exchange in the absence of arginine. Product inhibition studies showed that arginine was competitive with AP and noncompetitive with ADP; whereas ATP was competitive with ADP and noncompetitive with arginine. The results from initial velocity, radioisotope exchange, and product inhibition studies suggested that the enzyme has a rapid equilibrium, random mechanism.     

Occurrence of Eulaema (Apeulaema) pseudocingulata Oliveira (Hymenoptera: Apidae: Euglossini) in the Platina Basin, Mato Grosso State, Brazil

This study was conducted in the Chapada dos Guimar?es National Park and in the Província Serrana of Mato Grosso state, from May 2003 to July 2005 and involved the use of chemical baits to attract male orchid bees. A total of 498 males were captured, of which 38 were Eulaema (Apeulaema) pseudocingulata Oliveira. Twenty-nine of these were collected in the national park and nine in the Província Serrana. E. pseudocingulata was reported as endemic to the Amazon Basin, however in the Platina Basin the species is sympatric to E. cingulata (Fabricius), a sibling species of similar morphology and color pattern but with a broader geographic distribution.     

Organization of the antennal lobe in the queen honey bee,Apis mellifera L. (Hymenoptera : Apidae)

Antennal afferent pathway topography was studied in the queen honey bee, Apis mellifera L. (Hymenoptera : Apidae) by staining with cobalt chloride applied directly to the cut antennal axons. Antennal lobe organization in the queen was compared with those in worker and drone bees. The organization is similar in queen and worker bees. For the first time in a female insect the possible existence of a macroglomerulus is shown, which may be involved in the processing of species-specific information. A comparative quantitative neuromorphological study of the glomeruli was performed between young queens (8-day old) and 1-yr-old queens. The mean volume of the glomeruli is 46% greater in the older queens.     

Cytogenetic characterization of Rhamdia quelen (Siluriformes, Heptapteridae) from the Bodoquena Plateau, Mato Grosso do Sul, Brazil

We made a cytogenetic study of the fish Rhamdia quelen collected from the Bodoquena Plateau, an isolated national park region in Mato Grosso do Sul State, Brazil. The diploid number was 2n = 58, with 36 metacentric + 16 submetacentric + 6 subtelocentric chromosomes. We found one to three B chromosomes, which were metacentric and submetacentric and of medium size, showing both intra- and interindividual variation. The nucleolus organizer region (NOR) was located in the terminal region of the short arm of submetacentric pair 20. Staining with CMA3 fluorochrome revealed the NOR location, while there was no evidence of fluorescent staining with DAPI. C banding revealed heterochromatin mainly in the terminal regions of the chromosome arms, including the NOR pair. In addition, metacentric pair 2 showed three heterochromatic blocks in the terminal portions and in the pericentromeric region. The B chromosomes appeared euchromatic. The CB + CMA3 staining combination demonstrated only one chromosome pair with fluorescence, probably the NOR-bearing one, while CB + DAPI gave various fluorescent signals, including metacentric pair 2, indicating that these heterochromatic regions are AT-rich in this population of R. quelen. The R. quelen population in this isolated region of Brazil is chromosomally distinct from that of other populations that have been studied.     

Relation between the size of the acid gland and the quantity of venom produced in Africanized bee, Apis mellifera L. (Hymenoptera: Apidae), in the region of Dourados, MS, Brazil

Crosses between African and European honeybees in Brazil resulted in a highly defensive hybrid bee. The acid gland is important in the expression of this characteristic, being responsible for venom production. Morphological variations in this gland could influence the quantity of venom. Glandular morphology was analyzed, along with the quantity of venom produced and the bees' genetic characteristics. The gland and the venom reservoir were removed from workers. The gland was placed on a histological frame for measurement and the contents of the reservoir were weighed. The results were submitted to an analysis of regression and submitted to Test Z, to evaluate the differences between the averages. The phenotypes were evaluated according to the standard found in literature. Gland length varied from 7.42 mm to 20.33 mm, the quantity of venom from 0.19 mg to 0.34 mg, and as far as the genetic characteristics are concerned, 63.3% of the colonies had workers with large glands. In 53.3% of the colonies, 90% of individuals had simple glands, suggesting the evolutionary process leading to the loss of branching, since the presence of branching indicates primitiveness. The production of venom is associated with the length of the gland and branching does not influence the quantity of venom. There was no statistical difference between the size of the branched and simple glands or in the quantity of venom produced, therefore the large glands can favor commercial exploration of venom, producing larger quantities.     

Detection of Leishmania DNA in phlebotomines captured in Campo Grande, Mato Grosso do Sul, Brazil

Over the past years, leishmaniases have become a public health issue in the Brazilian state of Mato Grosso do Sul, particularly in Campo Grande, the state capital. The purpose of this study was to detect the presence of Leishmania DNA in the population of phlebotomine sandflies using DNA amplification by PCR. Insect captures were carried out from 4 pm. to 7 am for 4 consecutive days each month from October 2005 to September 2006 in 16 neighborhoods located in 7 urban regions of Campo Grande. Traps were placed indoors and in the vicinity of households. As many as 971 males and 203 females were collected. One hundred and five naturally fed females were identified and grouped as 1- to 4-specimen pools. DNA extraction was carried out using whole insects. Lutzomyia longipalpis predominated, accounting for 99.15% of the phlebotomines captured. Also found was Nyssomyia whitmani, the vector of tegumentary leishmaniasis. Abundance was greatest in the vicinity of households (69.8% of the phlebotomines captured). As revealed by PCR, parasites were present in 1.9% of the Leishmania spp. specimens investigated and confirmed for visceral leishmaniasis.     

Phlebotomines (Diptera: Psychodidae) in forested areas of the Serra da Bodoquena, state of Mato Grosso do Sul, Brazil

Investigation was undertaken on the behaviour of the phlebotomine fauna in caves, forests, and anthropic environments of the Serra da Bodoquena, between January 1998 and January 2000. This paper reports on the phlebotomines captured in forested areas with automatic light traps (ALT), Shannon traps (ST), aspiration (AN), at natural resting sites and by human attractiveness (HA) during 24 h. The diversity and abundance of the species were investigated with ALT installed at 16 points (ground level) and 6 in the canopy. Natural infection by flagellates was investigated in females captured with ST AN, and HA. The sandfly fauna was represented by 23 species. Twenty-two of these were captured with ALT 15 of them on the western side, and 20 on the eastern. Lutzomyia longipalpis and Nyssomyia whitmani were the most abundant on the former and this species together with Lutzomyia almerioi on the latter side. On the eastern side the ecotopes located close to caves rendered a significantly greater number (P < or = 0.01) of specimens than did more distant sites. On this side Lu. almerioi contributed with 56% of the total number of specimens. Lu. almerioi females were predominantly attracted by humans (96.4%) and by ST (93.2%) and three of the 2173 dissected (0.138%) presented natural infection by flagellates. The attraction of Lu. almerioi to humans occurred during all seasons, predominantly in the summer, and in nocturnal and diurnal periods. Thus it is bothersome to inhabitants of and visitors to the Bodoquena ridge and a potential vector of flagellates.     

Yield per recruit of the pacu Piaractus mesopotamicus (Holmberg, 1887) in the pantanal of Mato Grosso do Sul, Brazil.

Among the several fish species comercially exploited at the Pantanal of Mato Grosso do Sul, the "pacu" (Piaractus mesopotamicus) stands as one of the most important. Information regarding its exploitation level is necessary for the proper management of its stocks. Between 1996 and 1997 data on total length of the pacu were collected on a monthly basis from specimens caught by professional and sport fishers in the municipality of Corumbá. These data were used to estimate growth parameters and to assess the exploitation level for this species, applying the Beverton and Holt yield per recruit model. Length frequency analysis, carried out with the software FISAT (ELEFAN), was used to estimate growth parameters: 1996: L(infinity) = 87.20 cm; K = 0.34 year(-1); phi(')=3.41; C = 0.74; WP = 0.81; Longevity = 8.40 years; and 1997: L(infinity) = 86.50 cm; K = 0.34 year(-1); phi(')=3.40; C = 0.60; WP = 0.80; Longevity = 8.40 years. The value for t(0) is -0.363 years for mean values of L(infinity) and k. The weight-length relationship, calculated from data derived from experimental fisheries carried out in 1999 and 2000, is described by the equation: W = 0.048LF(2.835). Estimated mortalities and survival rates were: 1996: Z = 1.51 year(-1); M = 0.62 year(-1); F = 0.89 year(-1); S = 21.9%; and 1997: Z = 1.65 year(-1); M = 0.63 year(-1); F = 1.02 year(-1); S = 19.1%. The yield per recruit analysis showed the following values: F(Present) = 0.96 year(-1); F(max) = 0.67 year(-1) ; F(0.1) = 0.51 year(-1) (for L(c) = 26.7 cm). These results suggest that the pacu is overexploited in the area, so that restrictive measures are in need to manage the pacu fisheries.     

Bombus impatiens (Hymenoptera: Apidae): an alternative to Apis mellifera (Hymenoptera: Apidae) for lowbush blueberry pollination.

The pollination effectiveness of the commercially reared bumble bee Bombus impatiens Cresson, was compared in field studies to the honey bee, Apis mellifera L., for lowbush blueberry, Vaccinium angustifolium Ait. A preliminary study indicated that B. impatiens had potential as an alternative pollinator. In a 3-yr study, percentage fruit set, percentage harvested berries, berry weight, and seeds per berry were compared in blueberry fields stocked at 7.5 A. mellifera hives per hectare to 5, 7.5, or 10 B. impatiens colonies per hectare. Percentage of harvested berries (yield) was significantly higher in fields stocked with B. impatiens at 10 colonies per hectare. No other parameters measuring pollinator effectiveness were significantly different at 5, 7.5, or 10 colonies per hectare. Flower handling time was significantly faster for B. impatiens and it more frequently collected blueberry pollen. All parameters of pollinator effectiveness were similar for B. impatiens, A. mellifera, and native wild bees in a follow-up study. Overall, B. impatiens was a suitable alternative to A. mellifera.     

Ultrastructural modifications in the venom glands of workers of Apis mellifera L. (Hymenoptera: Apidae) promoted by topical application of juvenile hormone

The present study analyzed, the influence of the treatment with juvenile hormone on the ultrastructure of Apis mellifera L. workers' venom glands. Newly emerged workers received topical application of 1 microl of juvenile hormone diluted in hexane, in the concentration of 2 microg/pl. Two controls were used; one control received no treatment (group C1) and other received topical application of 1 microl of hexane (group C2). The aspect of the glandular cells, in not treated newly emerged workers, showed that they are not yet secreting actively. Cellular modifications happened according to the worker age and to the glandular area considered. The most active phase of the gland happened from the emergence to the 14th day. At the 25th day the cells had already lost their secretory characteristic, being the distal area the first to suffer degeneration. The treatment with juvenile hormone and hexane altered the temporal sequence of the glandular cycle, forwarding the secretory cycle and degeneration of the venom gland.     

Effect of Non-Ionizing Electromagnetic Radiation on Behavior of the Honeybee,Apis mellifera L. (Hymenoptera,Apidae)

Entomological Review - We studied the effect of non-ionizing electromagnetic radiation (EMR) of a Wi-Fi router on sensory olfactory excitability, food motivation, and the ability to form a...