Influence of larval and pupal products on the oviposition behavior of Aedes Fluviatilis (Lutz) (Diptera: Culicidae)

Several larval and pupal products of Aedes fluviatilis (Lutz) were tested for their influence on the oviposition behaviour of females of the same species. Significant (alfa = 0,05) atractiveness was shown by: larval water, previously containing 5 to 15 larvae/1,5 ml; larval water, preserved up to 38 days; evaporate and reconstructed larval water extracts up to 2 years after production and water filtered through fresh or dried ground larvae. hexanic larval water extracts and water filtered through fresh or dired ground pupae did not influence oviposition.

The use of dacron plates for DOT enzyme-linked immunosorbent assay (DOT-ELISA)

Dacron (polyethylenetherephthalate) is proposed as a matrix for dot-ELISA procedures, as an alternative to nitrocellulose. Plates of dacron were partially hydrazinolyzed and hydrazide groups introduced were converted to azide groups. The derivative dacron-antigen was covalently linked on to the plates through these azide groups. The derivative dacron-antigen was exaustively washed according to CROOK and antigen was still fixed onto the plates. Protein F1A purified from Yersinia pestis was used as a model. Triration of sera from immunized and non immunized rabbits against this protein was carried out by employing the dot-ELISA method. No significant difference was observed using dacron-antigen and nitrocellulose-antigen preparations. However, both procedures showed to have a significant better performance in comparasion with the passive hemagglutination method. The specificity and reproductibility of the dot-ELISA assay using both preparations showed a similar behaviour. Nitrocellulose preparation was stable at 4ºC, 28ºC and -20ºC for 90 days, whereas the dacron-antigen derivative was stable only when stored at 4ºC. Dacron-antigen derivative could be re-used when the spot developing was proceeded using 4-chloro-1-naphtol as substrate.

Effect of Niclosamide (Bayluscide WP 70 (R)), Anacardium occidentale hexane extract and Euphorbia splendens latex on behavior of Biomphalaria glabrata (Say, 1818), under laboratory conditions

The repellent effect of the molluscicides Niclosamide (Bayluscide WP 70 (R)), Anacardium occidentale and the latex of Euphorbia splendens on Biomphalaria glabrata was observed through the investigation of the occurrence of escape behavior among molluscs that were exposed to dosages lower than the LD 50. The total number of individuals out of water among the surviving snails in the control group provided a "Natural Escape Index". The comparison between this total and the total number of surviving snails in each group exposed to the different dosages of the molluscicides after 24 hr provided the "Molluscicide Escape Index" and the detection of a "Repellency Range" to these snails. The escape indexes for Niclosamide, A. occidentale and E. splendens were 10, 6.22 and 6.44 respectively. Repellency occurred at the following concentration ranges: 0.01, 0.02 and 0.03 ppm Bayluscide, 0.1, 0.2 and 0.3 ppm A. occidentale and 0.05, 0.10, 0.15 and 0.20 ppm E. splendens. The Natural Escape Index obtained in the control group was zero.

Behavior of Biomphalaria glabrata Say, 1818 (Gastropoda: Planorbidae): I. Morphophysiology of the Mantle Cavity

Using longitudinal and transverse anatomical sections, we observed that the three cristae of the mantle of Biomphalaria glabrata (renal, rectal and dorsolateral cristae) divide the mantle cavity into three chambers which we designated air or pulmonary chamber, water inflow chamber and water outflow chamber. Using videotape filming, we observed the inflow and outflow of air and water into and from the mantle cavity and we related their probable functions such as flotation, oxygen reservoir and transport, excreta circulation and elimination, water skeleton, and modification of specific weight. To determine whether the air bubble may function as a physical gill in this species we submitted three groups of snails to different systems in which water contained the same level of dissolved oxygen whereas the gas phases were atmospheric air, pure nitrogen or pure oxygen. We observed the following parameters: time of permanence on the surface, time of immersion, and frequency at which the snails reached the surface. These results did not demonstrate a physical gill function; morphological analysis of the mantle cavity indicates this possibility

Population dynamics and feeding behavior of Triatoma brasiliensis and Triatoma pseudomaculata, main vectors of Chagas disease in Northeastern Brazil

Biological parameters of Triatoma brasiliensis and T. pseudomaculata that could influence the epidemiological importance of these insects as vectors of Trypanosoma cruzi were compared. The parameters studied were incubation period, interval between hatching or moulting and first feeding, number of blood meals, development time, mortality, net reproductive rate, instantaneous daily reproductive rate, time-lapse before starting feeding, duration of feeding, blood ingestion capacity, occurrence of defecation and blood ingestion velocity. Most aspects of feeding were similar for the two species, although T. pseudomaculata had a longer life cycle than T. brasiliensis producing one and two generations per year, respectively. The two species had similar instantaneous daily rates of population growth.

Development of genital plates in nymphs of Triatoma pallidipennis, Stål 1872, (Hemiptera: Reduviidae) and its application as sexing method

Searching for morphometric differences between sexes in immature forms, the development of genital plates in the exuviae of Triatoma pallidipennis Stål 1872nymphs was studied. Differences were found in the form and size of the 9th genital urosternite, it is larger and wider in males as compared to females. This difference is reported in several South American Triatoma species. From our results it is possible to sex early stages from microscopic observation of genital plates in whole insects.

Structural organization of Trypanosoma cruzi

Since the initial description of Trypanosoma cruzi by Carlos Chagas in 1909, several research groups have used different microscopic techniques to obtain detailed information about the various developmental stages found in the life cycle of this intracellular parasite. This review describes the present knowledge on the organization of the most important structures and organelles found in the protozoan, such as the cell surface, flagellum, cytoskeleton, kinetoplast-mitochondrion complex, glycosome, acidocalcisome, contractile vacuole, lipid inclusions, the secretory pathway, endocytic pathway and the nucleus.

Feeding behavior of Triatoma vitticeps (Reduviidae: Triatominae) in the state of Minas Gerais, Brazil

The objective of this study was to evaluate the feeding behavior of Triatoma vitticeps through the identification of its food sources and the characterization of the blood ingestion process. In addition, we aimed to verify if the saliva of this vector interferes with the perception of the host during the feedings by creating a nervous impulse. Here, we demonstrated that the T. vitticeps saliva reduces, gradually and irreversibly, the amplitude of the compound action potential of the nervous fibre, which helps decrease the perception of the insect by the host. The precipitin reaction demonstrated the feeding eclecticism of this vector, with the identification of eight food sources - most of them found simultaneously in the same insect. The analysis of the electrical signals produced by the cibarial pump during meals demonstrated that the best feeding performance of T. vitticeps nymphs that fed on pigeons is mainly due to the higher contraction frequency of the pump. The longer contact period with the host to obtain a complete meal compared with other triatominae species of the same instar could favor the occurrence of multiple blood sources in T. vitticeps under natural conditions, as it was evidenced by the precipitin test.

Prokaryotic cells: structural organisation of the cytoskeleton and organelles

For many years, prokaryotic cells were distinguished from eukaryotic cells based on the simplicity of their cytoplasm, in which the presence of organelles and cytoskeletal structures had not been discovered. Based on current knowledge, this review describes the complex components of the prokaryotic cell cytoskeleton, including (i) tubulin homologues composed of FtsZ, BtuA, BtuB and several associated proteins, which play a fundamental role in cell division, (ii) actin-like homologues, such as MreB and Mb1, which are involved in controlling cell width and cell length, and (iii) intermediate filament homologues, including crescentin and CfpA, which localise on the concave side of a bacterium and along its inner curvature and associate with its membrane. Some prokaryotes exhibit specialised membrane-bound organelles in the cytoplasm, such as magnetosomes and acidocalcisomes, as well as protein complexes, such as carboxysomes. This review also examines recent data on the presence of nanotubes, which are structures that are well characterised in mammalian cells that allow direct contact and communication between cells.

Therapeutic play in preparing for surgery: behavior of preschool children during the perioperative period

Objective:to describe the behavior of children during the instructional session of therapeutic play (ITP) in the preoperative period and to verify the behavior presented by them during the perioperative period. Methods: Exploratory descriptive study with a quantitative approach, developed in a large private hospital in Sao Paulo, in which the behaviors presented by 30 children between three and five years old, undergoing minor surgery were seen at the hospital during the session of TP and in the surgical center, from admission to awaken from anesthesia. Results: Most children participated in the ITP session (21; 70%), entered the surgical room spontaneously (22; 73.3%) without resisting mother separation (24; 80%), collaborating with the anesthetic procedure (16; 53.3%) and quietly awakening from anesthesia (26; 87%). Conclusion: The use of ITP led the child to understand the surgical procedure, making it less traumatic.


A possible territorial or recognition behavior of Leptoglossus zonatus (Dallas) (Heteroptera, Coreidae)

The coreid Leptoglossus zonatus (Dallas, 1852) is commonly found in corn (Zea mays L.) fields in Brazil, and it has been observed flying and landing on objects or persons near these fields. During January, 1995, this behavior was studied in corn plantations. Results indicated that the bugs concentrated on objects (plastic cylinders traps) introduced into their habitat and that their number increased during the first 24 hs. However, as time passed (8 days), this possible territorial or recognition behavior gradually decreased, and tended to disappear.

Surface swimming behavior of the curculionid Ochetina uniformis Pascoe (Erirhininae, Stenopelmini) and Ludovix fasciatus (Gyllenhal) (Curculioninae, Erodiscini)

The swimming behavior exhibited by specimens of L. fasciatus and O. uniformis was analyzed frame-by-frame with video observation recorded with a digital camera, attached to a stereomicroscope. Adults of O. uniformis, an aquatic insect, swim with all three pairs of legs. During the process of swimming the majority of the abdomen and rostrum remain submerged, part of the fore and hind tibiae remain above the surface, while the mid tibiae remain submerged. The mesothoracic legs, during the power-stroke stage, provide the greatest thrust while the metathoracic legs provide the least forward propulsion. The prothoracic legs, extended forward, help to direct the swimming. The semi-aquatic specie L. fasciatus shows the same swimming style as O. uniformis, that is, with movement of all the three pairs of legs; the mesothoracic legs are responsible for the main propulsion. The insect body remains on the water surface during the process of swimming, while the legs remain submerged. Both species complete a swimming cycle in 0.33 and 0.32 seconds, respectively, with an average speed of 1.38 cm/s and a maximum and minimum swimming duration time of 11.15 and 5.05 minutes, respectively, for L. fasciatus. The swimming behavior exhibited by O. uniformis and L. fasciatus corresponds to the style known as a breast strokelike maneuver. This is the first record of this kind of swimming for both species here observed and increases to seven the number of genera of Curculionidae exhibiting this behavior.

Occurrence, biology and behavior of Liogenys fuscus Blanchard (Insecta, Coleoptera, Scarabaeidae) in Aquidauana, Mato Grosso do Sul, Brazil

Due to the importance of some Pleurosticti Scarabaeidae as agricultural pests allied to information absence on the species that occur in Brazilian Central-West region, on studies occurrence, biology and behavior on this group of scarabs were conducted. Biology and behavioral studies started with Liogenys fuscus Blanchard, 1850 (Melolonthinae), a very common species and were developed in Aquidauana, Mato Grosso do Sul. Adult beetles were collected from light traps from February 2005 to January 2007, at the experimental farm of the Universidade Estadual de Mato Grosso do Sul in Aquidauana (UEMS). In the laboratory adults were placed in plastic containers with soil with sprouts of Brachiaria decumbens Stapf (Poaceae). Eggs were transferred to a climatized chamber at 26 ± 1º C with a 12hourlight, 12hour darkness photoperiod cycle. Adult flight activity occurred in August and in September to December from 06:00 pm to 06:00 am, with the largest number of individuals flying from 07:00 to 10:00 pm. Eggs measured 1 x 1.5 mm and were laid individually or in groups in soil chambers; eggs were initially white and became yellow near hatching. The embryonic period lasted 14.3 days; first, second and third instars lasted 28.5, 48.8, and 68.2 days, respectively. The prepupal period lasted 120.2 days and the prepupa stayed inactive in soil. The mean duration of pupal stage was 27.5 days and the mean longevity of adults was 23.6 days. In laboratory the calling behavior between males and females was observed; copulation lasted, in mean, 25 minutes.

First description of reproductive behavior of the Amazonian damselfly Chalcopteryx rutilans (Rambur) (Odonata, Polythoridae)

Polythoridae comprise a widespread group of species in the New World tropics, but little is known about their behavior or life history. Here, we described the reproductive behavior of Amazonian Chalchopteryx rutilans, using mark-recapture techniques. Males were resident and territorial, though we found disputes (complex flight manoeuvres) to be rare. Trunks (rotting wood) were important to male persistence in sites, as these are the locations preferred by females for oviposition. The mating system of C. rutilans may be comparable to the resource limitation category, described by Conrad & Pritchard (1992), where males cannot control female access to oviposition sites. So, female choice becomes important and apparently, the observed displays (in which males flash the coppery coloration of their hind wings) may be related to attraction of females to territories, as in a lek system.