Mario Antonio Navarro da Silva

Amblyomma aureolatum and Ixodes auritulus (Acari: Ixodidae) on birds in southern Brazil, with notes on their ecology.

Between January 1999 and December 2000, 876 bird specimens were captured in three different ecological environments from the Reinhard Maack Park, Curitiba, State of Paraná, southern Brazil. A total of 142 birds (16.2%) were infested with Amblyomma aureolatum (Pallas 1772) (N = 699) and/or Ixodes auritulus Neumann, 1904 (N = 18) ticks. Questing A. aureolatum nymphs (N = 2) and adults (N = 5) were also collected from the soil and the vegetation. None of the I. auritulus were collected off-host. We collected only immatures of A. aureolatum on birds, but all life stages of I. auritulus. The latter species was collected on Turdus rufiventris and on Synallaxis ruficapilla, which is herein recognized as a host of I. auritulus for the first time. Moreover, this is also the first report of A. aureolatum infesting birds, and 16 different bird species were found infested. It was observed that larval infestation was positively correlated with the dry and cold season, while nymphal infestation was positively correlated with the warm and rainy season. Although only 2-years worth of data is provided, our results suggest the infestation of birds by ticks was significantly higher at the biotopes formed by forest at its first stage of regeneration ‘capoeira’ and the original Araucaria forest habitat ‘mata’ than the ecotone between forest and urban areas ‘peripheral area’.

AEDES AEGYPTI AND AEDES ALBOPICTUS (DIPTERA: CULICIDAE): COEXISTENCE AND SUSCEPTIBILITY TO TEMEPHOS, IN MUNICIPALITIES WITH OCCURRENCE OF DENGUE AND DIFFERENTIATED CHARACTERISTICS OF URBANIZATION

INTRODUCTION The aim of the present study was to verify the coexistence between Aedes aegypti and Aedes albopictus populations in municipalities of the States of Paraná and Santa Catarina with different urbanization profiles where dengue occurs and evaluate their susceptibility to the organophosphate temephos. METHODS The number of eggs per ovitrap were counted and incubated for hatching to identify the species. Data analysis of the populations was conducted to determine randomness and aggregation, using the variance-to-mean ratio (index of dispersion). Susceptibility to temephos was evaluated by estimation of the resistance ratios RR50 and RR95. Aedes aegypti samples were compared with the population Rockefeller and Aedes albopictus samples were compared with a population from the State of Santa Catarina and with the Rockefeller population. RESULTS Coexistence between Aedes aegypti and Aedes albopictus and the aggregation of their eggs were observed at all the sites analyzed in the State of Paraná. CONCLUSIONS All the Aedes aegypti populations from the State of Parana showed alteration in susceptibility status to the organophosphate temephos, revealing incipient resistance. Similarly, all the Aedes albopictus populations (States of Paraná and Santa Catarina) presented survival when exposed to the organophosphate temephos.

First report on susceptibility of wild Aedes aegypti (Diptera: Culicidae) using Carapa guianensis (Meliaceae) and Copaifera sp. (Leguminosae)

Oils of Carapa guianensis and Copaifera spp. are well known in the Amazonian region as natural insect repellent, and studies have reported their efficiency as larvicide against some laboratory mosquito species. However, in wild populations of mosquitoes, these oils have not yet been evaluated. Thus, the objective of this study was to investigate their efficiency as larvicide in wild populations of Aedes aegypti with a history of exposure to organophosphate. The susceptibility of larvae was determined under three different temperatures, 15°C, 20°C, and 30°C. For each test, 1,000 larvae were used (late third instar and early fourth instar—four replicates of 25 larvae per concentration). Statistical tests were used to identify significant differences. The results demonstrated that as the laboratory A. aegypti, the wild populations of A. aegypti were also susceptible to C. guianensis and Copaifera sp. oils. The lethal concentrations for Copaifera sp. ranged from LC50 47 to LC90 91 (milligrams per liter), and for C. guianensis, they were LC50 136 to LC90 551 (milligrams per liter). In relation to different temperature, the effectiveness of the oils on larvae mortality was directly related to the increase of temperature, and better results were observed for temperature at 25°C. The results presented here indicate the potential larvicidal activity of C. guianensis and species of Copaifera, in populations of A. aegypti from the wild. Therefore, the results presented here are very important since such populations are primarily responsible for transmitting the dengue virus in the environment.

Avaliação da influência da temperatura sobre o desenvolvimento de Aedes albopictus

OBJECTIVE To verify the temperatures influence on the Aedes albopictus development stages under laboratory conditions. METHODS The development period of eggs, larvae and pupas were assessed at constant temperatures, 15 degrees C, 20 degrees C, 25 degrees C and 30 degrees C, inside acclimatized chambers with 70-85% of relative humidity, and LD 12:12 h. The effect of the four constant temperatures was assessed using variance analysis. RESULTS The incubation periods of eggs were 38.38, 19.09, 13.10, and 10.44 days. Larval periods for males lasted 30.13, 13.83, 7.36, and 5.57 days; for females it lasted 33.22, 15.00, 8.06, and 6.16 days. Pupil period for males lasted 8.01, 4.92, 2.40, and 1.76 days; and for females it lasted 8.15, 5.11, 2.60, and 1.88 days under the temperatures of 15 degrees C, 20 degrees C, 25 degrees C and 30 degrees C, respectively. In all development stages for all temperatures, significant differences were found at the level of 5%. The development period was inversely associated to the temperature, and the larval period was shorter in males than in females. Under the temperatures of 20 degrees C and 30 degrees C, the development of immature stages was shorter and their viability was greater than at 15 degrees C. CONCLUSIONS In the conditions the experiment was performed, the temperature affected significantly and inversely proportional Aedes albopictus immature stages. These results show that immature stages are more susceptible at low temperatures due to the longer time required completing their development. This could be used in vector control strategies.

Criadouros de imaturos de mosquitos (Diptera, Culicidae) introduzidos em mata preservada na área urbana de Curitiba, Paraná, Brasil

Mosquitoes ecological features were studied in a preserved forest - Capao da Imbuia - placed in the urban area of Curitiba City, Parana, Brasil. In this research were noted immature forms in artificial recipients made by different materiais. Five species were found in this recipients: Culex (Culex) acharistus Root, 1927, Culex (Culex) group coronator Dyar & Kanb, 1906, Culex (Culex) eduardoi Casal & Garcia, 1968, Culex (Culex) quinquefasciatus Say, 1823 and Toxorhynchites (Lynchiella) theobaldi (Dyar & Kanb, 1906). Its very important to know the mosquitoes that in urban area due they carry human desease agents by some species.

Mosquitos (Diptera, Culicidae) capturados com isca humana em área preservada de Curitiba, Paraná

In a residual forest patch at Curitiba city, captures of culicidae were performed using human bait, at land levei, between 5:00 to 9:00 hours p.m. The period covered 12 months, march-90 to march-91 and the captures lasted 108 hours. In this periodo were caught 18 specie distributed in nine genera. The four specie caught that made more than ten percent were Aedes (Ochlerotatus) scapularis (Rondani, 1848), Culex (Culex) group coronator Dyar & Knab, 1906, Culex (Culex) quinquefasciatus Say, 1823 e Aedes (Ochlerotatus) crinifer (Theobald, 1903). The most frequent specie was Culex coronator. Along the season, the best yield was at autumn. With regard to the meteorological pattern, Aedes scapularis showed a positive and significative associalion with the rainfall and so do Aedes crinifer with the mean temperature. However, Culex coronator e Culex quinquefasciatus showed no association between air humidity and rainfall. During the time interval analised, bitting activity was performed firstly by Aedes scapularis and Aedes crinifer and then by Culex coronator and Culex quinquefasciatus.

The combined action of phytolarvicides for the control of dengue fever vector, Aedes aegypti

Amongst other botanical sources, Annona muricata L., Annonaceae, seeds and Piper nigrum L., Piperaceae, fruits are particularly enriched with acetogenins and piperine-related amides, respectively. These crude ethanolic extracts are potent Aedes aegypti bioactives that can kill Aedes aegypti larvae (dengue fever mosquito). A. muricata displayed a 93.48 µg/mL LC50 and P. nigrum an 1.84 µg/mL LC50. An uncommon pharmacognostical/toxicological approach was used, namely different combinations of both extracts to achieve an improved lethal effect on the larvae. The independence test (χ2) was utilized to evaluate the combination of the two crude extracts. All of the tested combinations behaved synergistically and these novel results were attributed to the completely different biochemical mechanisms of the differentiated chemical substances that were present in the two botanical sources. Besides the two above selected plants, Melia azedarach L., Meliaceae, Origanum vulgare L., Lamiaceae, and Ilex paraguariensis A. St.-Hil., Aquifoliaceae, in order of decreasing toxicity, may also be sought as potential extracts for the sake of synergic combinations.

Biological activities of the essential oil from the leaves of Xylopia laevigata (Annonaceae)

The essential oil from the leaves of Xylopia laevigata was obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and GC/flame ionization detector (GC/FID). Thirty-six compounds representing 97.48% of the crude essential oil were identified. The major compounds identified were -muurolene (17.99%), -cadinene (13.45%), germacrene D (9.09%), bicyclogermacrene (7.00%), -copaene (5.98%), and (E)-caryophyllene (5.43%). The biological activities of the essential oil against Trypanosoma cruzi epimastigote forms, yeast, bacteria, Aedes aegypti larvae, antioxidant properties and antiproliferative activity against tumor cell lines were investigated. The essential oil showed trypanocidal activity with IC50 value of 93.9±2.6 μg/mL. For antibacterial and antifungal activities, the best results were observed against Staphylococcus aureus (ATCC14458), Staphylococcus epidermidis (ATCC1228) and Candida tropicalis (ATCC 157), all with a minimal inhibitory concentration value of 100 μg/mL. The essential oil showed antioxidant capacity of 1468.96 μmol of TE/g in the oxygen radical absorbance capacity (ORACFL) assay. The oil showed moderate larvicidal activity with LC50 value of 632.36 μg/mL. The essential oil exhibited potent antiproliferative activity against all cell lines evaluated with total growth inhibition (TGI) value <40 μg/mL, exception for K562 cell line (TGI>250 μg/mL). The highest activity was observed against cell lines of UACC-62, NCI-ADR/RES and NCI-H460, with TGI values of 4.03, 4.26 and 8.37 μg/mL, respectively. For the VERO cell (non-cancer cell line), the TGI value was of 15.94 μg/mL.

Comunidade de mosquitos (Diptera, Culicidae) em recipientes antrópicos introduzidos em área rural e urbana da região metropolitana de Curitiba, Paraná, Brasil

Immature stages of Culicidae were collected in artificial containers in three conditions, between November 1997 and November 1998, in the rural area of Sao Jose dos Pinhais, Parana, Brazil. Eight species were identified: Culex (Culex) eduardoi Casal & Garcia, 1968, Culex (Culex) acharistus Root, 1927, Culex (Culex) group coronator, Culex (Lutzia) bigoti Bellardi, 1962, Aedes (Protomacleaya) terrens (Walker, 1856), Limatus durhamii Theobald, 1901, Txorhynchites theobaldi (Dyar & Knab, 1906) and Phoniomyia sp. The Berger & Parker index was obtained for each condition and kind of container. These results were compared with those of Silva & Lozovei (1996) in the urban area of Curitiba. A greater number of species was observed in the rural area, with different dominance under each condition. The introduction of artificial containers can not show the number of Culicidae species that are present in an area, but it can indicate the species that show the greatest adaptability to environmental modifications produced by human activity.

Neotropical Ablabesmyia Johannsen (Diptera: Chironomidae, Tanypodinae)-part I.

This is a series of three manuscripts about the genus Ablabesmyia. In the first new species are described, three species are re-examined and keys to males, pupae and larvae of known neotropical species are provided and an emended generic diagnosis of Ablabesmyia is given. The second manuscript will analyze the molecular data of Neotropical species and the third one will check, through a phylogenetic analysis, the truth of subgenera. In this study, twenty-four new species of Ablabesmyia Johannsen are described and figured: A. arquata, A. cauame, A. commata, A. communiba, A. cordeiroi, A, depaulai, A. diversa, A. ducke, A. fazzari, A. fusariae, A. gessnerae, A. gigas, A. jaquirana, A. laurindoi, A. manauara, A. martha, A. novema, A. parannulata, A. parareissi, A. pinhoi, A. rafaeli, A. separata, A. strixinoae and A. suiamissu. We re-examined A. cinctipes (Johannsen), A. infumata (Edwards) and A. metica Roback. The species were collected in Brazil, in lentic systems. Keys to males, pupae and larvae of known neotropical species of the genus Ablabesmyia are provided and an emended generic diagnosis of Ablabesmyia is given.