Epidemiology of Oestrus ovis (Diptera: Oestridae) in sheep in Botucatu, State of São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Babesia spp. infection in dogs from rural areas of São Paulo State, Brazil

The status of Babesia spp. infection in dogs from rural areas of São Paulo State, Brazil was Studied. For this, l 50 animals were examined by blood smears and by PCR; the presence of tick infestation was also investigated. By the blood smear examination, 3 animals (2%) were detected positive and by PCR for Babesia spp. 12 (8%) were positive, with bands Visualized in 450 bp. Rhipicephalus sanguineus or Amblyomma spp. were found on 36 (24%) of the 150 dogs. Amblyomma species found were A. cajennense (9/36-25%) and A. ovale (9/36-25%). It was not possible to correlate the presence of R. sanguineus and the infection with Babesia spp. The sequencing of four positive samples demonstrated close identity with B. canis vogeli already characterized in Brazil.

Parasitism by Oestrus ovis: Influence of sheep breed and nematode infections

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

New records of endoparasites infecting Hypsiboas albopunctatus (Anura : Hylidae) in a savanna area in Brasilia, Brazil

Seventy specimens of Hypsiboas albopunctatus (Anura: Hylidae) were collected and surveyed for endoparasites in Brasilia, Brazil at the end of the rainy season (February and March) in 2005. Sixteen males (22.86%) were infected by Rhabdias sp., Aplectana sp., Cosmocerca sp., and Falcaustra mascula. Rhabdias sp., a lung parasite, presented the highest prevalence (8.57%), mean intensity of infestation (1.333), and mean abundance (0.114). Moreover, this is the first report of a rhabdiasid nematode in the Hylidae in Brazil. The intestinal parasites, Cosmocerca sp. and Aplectana sp., had a similar prevalence (5.71%), but the former presented a higher mean intensity of infestation and mean abundance. The behavior and food habits of amphibians are responsible for the differences in their helminthofauna, and this study presents four new records of nematodes in H. albopunctatus.

Characterization of the excretory/secretory products of Dermatobia hominis larvae, the human bot fly

Proteolytic activity in excretory/secretory products (ESP) of first- (L1), second- (L2) and third-instar (L3) larvae of Dermatobia hominis was analyzed through gelatin-gel and colorimetric enzyme assays with the chromogenic substrates azocasein and BApNA. The functional characterization of proteases was based on inhibition assays including synthetic inhibitors. ESP were obtained from new-hatched larvae reared in the laboratory and from second- and third-instar larvae removed from naturally infested cattle. Gelatin-gel analysis evidenced few bands of proteolysis, predominantly of high apparent molecular masses, in ESP of L1, whereas in the gel of L2 and U ESP there was a wide range of proteolytic activity most of them not resolved in a single species. Azocasein assays revealed a progressive increase of protease activity from first- to third-instar larvae. Protease inhibitor assays revealed a predominance of metalloproteases in L1 ESP that could be related to a skin penetration process and to a diversion of host immune response. The predominance of serine proteases in L2 and L3 and the great tryptic activity presented by L3 ESP were attributed to an increasing trophic activity by the growing larvae, since the viability of adult flies strictly depends on larval abilities to assimilate nutrients from the host. Taking together, these results suggest that Dematobia larvae secrete/excrete different proteases that may be related to diverse functions during host penetration and infestation, which reinforces the relevance of the study of such proteolytic enzymes. (C) 2009 Elsevier B.V. All rights reserved.

Immune responses in sheep naturally infected with Oestrus ovis (Diptera: Oestridae) and gastrointestinal nematodes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Azadirachta indica A. Juss (neem) induced morphological changes on oocytes of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) tick females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultrastructure features of the midgut of the female adult Amblyomma cajennense ticks Fabricius, 1787 (Acari: Ixodidae) in several feeding stages and subjected to three infestations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Natural Infestations of the Mite Varroa destructor on the Development of Africanized Honeybee Workers (Apis mellifera)

The mite Varroa destructor (Anderson & Treuman 2000) has caused extensive damage to beekeeping worldwide. In Brazil, weather conditions and the strains of bees do not provide ideal conditions for mite parasitism, which is reflected in the low number of deaths of colonies caused by varroatosis well as the stability of infestation levels. The aim of this study was to evaluate the damage caused by the mite infestation in hives maintained in natural conditions. For this purpose the number of mites per bee was calculated and used to quantify the level of infestation in each colony. To record the mortality rates of parasitized bees during development daily checks were performed. The data were analyzed by G test of independence and a Test of Proportions. The results indicate that the rate of mortality of pupae and larvae was proportional to the degree of infestation in each colony, and all colonies showed mortality rates significantly higher than the control rate. A significant interaction among death rates recorded between the third and fourth days of larval life and the total death of larvae was found (G Test = 50.22; P < 0.0001). So, it can be concluded that bee inbreeding contributed significantly to the increase of the larval rate of mortality. In Africanized honeybee colonies infested by the mite Varroa destructor mortality rates in conditions of natural infestation varied from 6.65 to 9.89% in pupae (<(x)over bar>= 8.78%) and from 6.13 to 13.48% in larvae ((x) over bar = 9.91%), against 3.85% and 3.74% in the control colony, respectively. Therefore, in the infested colonies the average rates of mortality caused by the harmful effects of the mite were, respectively, 2.28 times and 2.65 times greater in those two developmental stages.

Histopathology and Ultrastructure Features of the Midgut of Adult Females of the Tick Amblyomma cajennense Fabricius, 1787 (Acari: Ixodidae) in Various Feeding Stages and Submitted to Three Infestations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure and function of the foregut and salivary glands of the synanthropic diplopod Urostreptus atrobrunneus (Spirostreptidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological Organization of the Dorsal Protuberance of Linepithema humile (Mayr, 1868) Ant's Larvae (Hymenoptera, Formicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estimativa do grau de infestação numa pastagem de Panicum maximum Jacq

Um piquete de capim-colonião (Panicum maximum Jacq) submetido a pastoreio contínuo e a roçadas periódicas revelou, seis anos após o plantio, elevado grau de infestação por outras plantas, destacando-se entre elas a grama-batatais (Paspalum notatum Flügge) que apresentou 85% de frequência e 20,9% de biomassa epígea seca relativa. As dicotiledóneas, em conjunto, apresentaram frequência de 95% e biomassa relativa de 38,7% mas a sua contribuição específica foi muito reduzida. O capim-colonião, por sua vez, apesar da frequência de 95%, apresentou apenas 32,2% de biomassa relativa (diminuição de 67,8%). Estas profundas alterações da flora e da vegetação podem ser atribuidas, em grande parte, a dois fatores: a) ação seletiva da roçadeira; b) preferências alimentares e disseminação endozoócora da gramabatatais pelos bovinos.

Temporal patterns of parasitism in Diatraea saccharalis Fabr. (Lep., Crambidae) populations at different spatial scales in sugarcane fields in Brazil

Biological control of Diatraea saccharalis is regarded as one of the best examples of successful classical biological control in Brazil. Since the introduction of the exotic parasitoid, Cotesia flavipes, from Pakistan at the beginning of the 1970s, decrease in D. saccharalis infestation in sugarcane fields has been attributed to the effectiveness of this agent. Recently, the native Tachinidae fly parasitoids (Lydella minense and Paratheresia claripalpis) have also been implicated in this success. However, quantitative data confirming the actual contribution of these agents to the control of D. saccharalis are rather limited. The purpose of this study was to investigate the dynamics of the interactions between D. saccharalis and its parasitoids, emphasizing the temporal patterns of parasitism. To investigate this question, a large data set comprising information collected from two sugarcane mills located in the state of São Paulo, Brazil (Barra and Sao Joao sugarcane mills), was analysed. Basically, the data set contained monthly information about the number of D. saccharalis larvae and their parasitoids in each sample (man-hour per sample), the sugarcane varieties cultivated, the age of the sugarcane plants (only at the Sao Joao sugarcane mill) as well as the sugarcane cut at sampling time. The data were collected from March 1984 to March 1997 and from May 1982 to December 1996 for the Barra and Sao Joao sugarcane mills, respectively. Temporal inverse density-dependent parasitism was predominant for both parasitoid species with respect to all spatial scales. Although the temporal pattern of parasitism was not directly density dependent, it was evident that the tachinids and C. flavipes presented positive numerical responses according to variations in D. saccharalis densities through time.

Spatial and temporal population interactions between the parasitoids Cotesia flavipes and Tachinidae flies: considerations on the adverse effects of biological control practice

Biological control of Diatraea saccharalis is regarded as one of the best examples of successful classical biological control in Brazil. Since the introduction of the exotic parasitoid Cotesia flavipes, the decrease of D. saccharalis infestation in sugarcane fields has been attributed to the effectiveness of this agent. Recently, the native tachinid fly parasitoids (Lydella minense and Paratheresia claripalpis) have also been implicated in the success. Here, we investigated the spatial and temporal population interactions between C. flavipes and the tachinid flies, and provide a critical analysis of the biological control practice, focusing on the undesirable effects of introductions of exotic natural enemies. To investigate these questions, a large data set comprising information from two sugarcane mills located in the state of São Paulo, Brazil (Barra and Sao Joao Mills), was analysed. Analysis of the correlation between C. flavipes and tachinid fly population densities through time revealed that such populations were inversely correlated in the Sao Joao Mill and not correlated in the Barra Mill. Logistic regressions were computed to investigate the proportion of sites occupied by the parasitoid species at both mills as a function of time. An increasing trend in the proportion of sites occupied by C. flavipes was observed, with a concomitant decrease of the sites occupied by tachinid flies. This effect was more intense in the Sao Joao Mill. Thus, there is a convincing possibility that constant releases of C. flavipes decreased the tachinid fly populations, resulting in an undesirable effect of biological control practice.