Population Dynamics and Growth Rates of Endosymbionts During Diaphorina citri (Hemiptera, Liviidae) Ontogeny

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Histopathological study of ovaries of Rhipicephalus sanguineus (Acari: Ixodidae) exposed to different thymol concentrations

Thymol is a monoterpene with proven acaricide action for several tick species. In addition to killing these ectoparasites, thymol can also reduce oviposition and egg hatch rate. However, the effects of thymol on the morphophysiology of tick ovaries are still unknown. Thus, the aim of this study was to evaluate the morphophysiological changes caused by this active principle in ovaries of Rhipicephalus sanguineus after a 6-day feeding period, through the application of morphohistochemical techniques. After the feeding period, a total of 50 females were divided into five groups and immersed in the following solutions: (I) distilled water (control), (II) 30 % ethanol (control), (III) 1.25 mg/mL thymol, (IV) 2.5 mg/mL thymol, and (V) 5.0 mg/mL thymol. The experimental groups were kept in a climatic chamber (27 +/- 1 A degrees C; RH 80 A +/- 10 %) for 5 days. After this period, morphological (hematoxylin/eosin) and histochemical (von Kossa) techniques were applied after remotion of the ovaries. The morphological results revealed large vacuoles in germ cells at different developmental stages and invaginations that represent deformations in the chorionic membrane. From the results obtained in this study, it was concluded that thymol interfered with the development of oocytes, which showed degeneration signs. The treatment containing 5.0 mg/mL thymol affected more accentuately the morphological development. Moreover, thymol also altered the calcium content of yolk granules, which generally showed an intense staining for this element.

Embryonic development and nourishment in the viviparous fish Poecilia vivipara (Cyprinodontiformes: Poeciliidae)

While viviparity confers protection to the embryos during gestation, it increases energetic costs for the mother, which acquires new relations to its offspring. Maternal-fetal transfer of nutrients can occur in different patterns: as lecithotrophy (nourished by yolk) or matrotrophy (nourished by the mother). The development of Poecilia vivipara embryos was described macroscopically and microscopically, and the form of nutritional provisioning was identified. Embryonic development was divided into three prefertilization and seven postfertilization stages. The first organ to appear is the notochord, followed by the nervous, digestive and cardiovascular systems, and then by muscles and eyes. Embryonic nutritional provisioning was lecithotrophic, with yolk persisting until the last developmental stages and rich in proteins and polysaccharides. This kind of embryonic nutrition confirms the pattern found in the family Poeciliidae.

Efeito de temperaturas alternadas sobre desenvolvimento de Aedes (Stegomyia) aegyoti (L.) (Diptera: Culicidae)

Aedes (Stegomyia) aegypti is a species of mosquitoes known to be the vector of diseases such as dengue and yellow fever, and a better understanding of aspects of their biology can help in the establishment of control strategies for the same. Several previous studies showed that temperature significantly affects the development of immature stages of insects. In general, higher temperatures (up to a threshold) accelerate the development of insects, and lower temperature retards the same. This rule also applies to mosquitoes, including Ae. aegypti. But not still know the effects of daily variation of temperature on the developmental stages of mosquitoes. And this detail is very important, since in natural breeding or artificial, The mosquitoes usually face temperature variations over a single day, which should interfere with its development until the emergence of the adult forms. For this reason, the objective of this study is to analyze the effect of alternating temperatures on the development of Ae. aegypti. To conduct the study, adults were collected active in the neighborhood Bela Vista Campus of UNESP - Rio Claro, SP, using a sweep net or using ovitraps for immatures, and the active search for breeding. Individuals collected were kept under experimental conditions in the laboratory. The adult samples were identified to species level, were considered for the experiments, only samples of Ae. aegypti. The insects were housed in plastic cages, suitable for creating flies. These were fed with sugar solution and blood meal on alternate days. The eggs obtained were used in the experiment with four different temperature regimes. The data collected were analyzed by evaluating whether the different treatments influenced the development of immature to adult, performing the Kruskal-Wallis test and the statistical software BioEstat. Statistical analysis of the sex ratio... (Complete abstract click electronic access below)

Períodos de interferência de Mucuna aterrima (Piper & Tracy) em cana-de-açúcar e seu controle químico

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Microscopic Evidence of the Opportunistic Reproductive Strategy and Early Sexual Maturation of the Small-Sized Characin Knodus moenkhausii (Characidae, Pisces)

We investigated the reproductive biology of Knodus moenkhausii, an abundantsmall-sized characin fish with broad occurrence in the Parana River basin, Bra-zil. Specimens were collected monthly to determine fecundity, length at firstmaturity, reproductive period and spawning type. Gonads were macroscopically classified according to their form, size and texture in three different stages(immature, maturing or mature). Histological procedures were conducted toconfirm gonadal developmental stages, and it was possible to notice thatmaturing females actually presented atretic oocytes, and all males that weremacroscopically classified as immature, maturing and mature actually presentedabundant spermatozoa in their gonads. Because of these discrepancies, a reclas-sification of gonadal maturations stages was needed after histological analysis,reinforcing its importance to studies on the reproduction of small characins.Reproduction occurred throughout the year though with two peaks. The lengthof the smallest mature individuals was 13 mm SL for males and 24 mm SL for females. Despite presenting relatively small batch fecundity, some life historytraits such as early reproduction, multiple spawning throughout the year, inassociation with known opportunistic feeding habits, explain the high abun-dance of this species in locations where it occurs.

Anatomia floral de espécies de Cyperaceae (Poales)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Metodologias de aplicação de sulfonamida heterocíclica no controle de Meloidogyne javanica e Pratylenchus brachyurus em soja

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Mortality dynamics of spodoptera frugiperda (lepidoptera: noctuidae) immatures in maize

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Early development of Betta splendens under stereomicroscopy and scanning electron microscopy

Betta splendens is a very important ornamental species. The current paper describes the embryonic and larval development of B. splendens under stereomicroscopy and scanning electron microscopy. Eggs and larvae from natural spawning were collected at different developmental stages at previously established intervals and analysed. The eggs of B. splendens are yellowish, clear, spherical, demersal, translucent and telolecithal with a large amount of yolk. Between 0-2 h post-initial collection (hpIC), the eggs were at the egg cell, first cleavage and morula stages. The blastula stage was identified at 2-3 hpIC and the early gastrula phase was observed at 3-4 hpIC with 20% epiboly, which was finalized after 13-18 hpIC. When the pre-larvae were ready to hatch, the appearance of somites and the free tail were observed, at 23-25 hpIC. At 29 hpIC, the majority of larvae had already hatched at an average temperature of 28.4 +/- 0.2 degrees C. The newly hatched larvae measured 2.47 +/- 0.044 mm total length. The mouth opened at 23 h post-hatching (hPH) and the yolk sac was totally absorbed at 73 hPH. After 156 hPH, the heart was pumping blood throughout the entire larval body. The caudal fin, operculum and eyes were well developed at 264 hPH. When metamorphosis was complete at 768 hPH, the larvae became juveniles. The current study presents the first results about early development of B. splendens and provides relevant information for its reproduction, rearing and biology.

Floral nectar production and nectary structure of a bee-pollinated shrub from Neotropical savanna

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Location, morphology and function of nephrocytes in termites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A substituição do meio TCM pelo meio BARC, suplementado com SFB, BSA ou PVA, para maturação de oócitos bovinos in vitro, não incrementa a subsequente produção de blastocistos

This study was carried out to assess the influence of bovine embryo culture medium Beltsville Agriculture Research Center (BARC), supplemented with FCS, BSA or PVA, on the in vitro oocyte maturation, evidenced by cleavage rate and blastocysts production at different developmental stages. Three experiments were performed, as follows: exp.1: addition of FCS to BARC medium at concentrations of 0, 5 and 10%; exp. 2: addition of BSA to BARC medium at concentrations of 0, 4 and 8 mg/ml; exp. 3: addition of PVA to BARC medium at concentrations of 0, 0.5 and 1.0 mg/ml. TCM 199 supplemented with bicarbonate, pyruvate, gentamicin sulfate, FSH, LH and FCS was used as control group. Oocytes obtained from cow ovaries at slaughterhouse were selected in PBS, and then matured in BARC medium supplemented with FSH, LH and gentamicin sulfate, according to the experimental design. Percoll gradient was used for sperm selection and TALP medium for IVF. In vitro embryo culture was in SOF-m medium; a humidified atmosphere with 5% CO2, in air, at 38.7oC was used for all steps. The number of oocytes reaching blastocyst, expanded blastocyst, and hatched blastocyt stages was recorded, respectively at 72 and 168 h post-insemination. ANOVA and Bonferroni t test were used to determine differences among groups. Differences of P<0.05 were taken as significant. Higher percentage (P<0.05) of cleaved oocytes was observed in group TCM + FCS than for the other groups matured in BARC supplemented with FCS or BSA, regardless the concentration used. However, the cleavage rate was similar between groups BARC plus PVA with 1 mg/ml (85.7%) and TCM + FCS (90.8%). Significant difference was found among groups for the production of blastocysts, with the control group yielding a higher number of blastocysts (results ranging from 47.4 to 51.4%, in comparison with groups using BARC + FCS (4.1 to 19.7%), BSA (1.4 to 5.6%) and PVA (5.7 to 10.6%). In conclusion, BARC medium supplemented with different macromolecules did not promote a beneficial effect on in vitro oocyte maturation, resulting in lower rate of cleavage and blastocyst production when compared with TCM + FCS medium.

Ceratoconjuntivite por Encephalitozoon hellem em periquitos agapornis (Agapornis spp.) no Brasil: relato de caso

Relata-se um caso de ceratoconjuntivite causada por Encephalitozoon hellem em agapornis (Agapornis spp.) adultos, provenientes de um criatório comercial. Cinco animais apresentaram sinais clínicos de ceratoconjuntivite, blefaroespasmo e blefaroedema bilateral, com presença de secreção seropurulenta. Amostras fecais foram colhidas e foi realizado exame coproparasitológico, com resultado negativo. Dois animais foram necropsiados, sendo detectados, em impressões de raspado de conjuntiva ocular, esporos e outros estádios evolutivos de Microsporidium. A confirmação do diagnóstico foi feita pela reação em cadeia de polimerase e sequenciamento de fragmentos amplificados, com utilização de primers específicos para o gene da subunidade 18S do rRNA de E. hellem. A análise dos fragmentos amplificados demonstrou 100% de similaridade com outras sequências de E. hellem publicadas no GenBank. Este é primeiro relato de infecção por E. hellem em aves no Brasil.

Gonadal Maturation in the Cobia Rachycentron canadum from the Northcentral Gulf of Mexico

Gonadal maturation of cobia, Rachycentron canadum, was evaluated by examining 508 specimens from its recreational fishery. Specimens were collected off southeast Louisiana to northwest Florida by hook-and-line during February through October 1987-1991. Fork lengths (FL) of these fish ranged from 580-1,530 mm, with corresponding weights of 2.0-43.5 kg. The female:male ratio was 1:0.37. Using a combination of oocyte size frequency and histological assessment of many of the fish, we determined that females were ripe from May through September, with atretic oocytes occurring in some fish from July through October. Degenerating hydrated oocytes in July and October and the presence of resting ovaries in July suggest two major spawning periods; however, monthly gonosomatic indices peaking in May, followed by a steady decline, do not support that finding. Ovaries were placed into undeveloped, early developing, mid-developing, or late developing categories based upon oocyte size-frequency distributions. Developing ovaries had two or three modes of oocytes larger than 30 μm. Batch fecundity was estimated to be 2.6×106 - 1.91×108 oocytes, depending on the size of fish/ovaries. The smallest female with oocytes exhibiting vitellogenesis was 834 mm FL. This fish was 2 years old based its otolith evaluation. The smallest male with an abundance of spermatozoa in its testes was 640 mm FL and 1 year old based on otolith evaluation; smaller males were not examined. Females larger than 840 mm FL had vitellogenic oocytes in March and April. A few fish still had vitellogenic oocytes in early October, but none did by late October. When Gilson’s fluid was used to assess ovarian tissue, the fresh weight of the tissue was reduced by 20% after being stored for 3 months. The diameter of oocytes shrunk about 25% in Gilson’s fluid which was 11% less than those fixed in formalin, embedded in paraffin, and sectioned. Tissue sections from specific individuals, each demonstrating a variety of different developmental stages, were similar regardless of whether they were obtained from the anterior, middle, or posterior portion of either ovary.