Resistance of cattle of various genetic groups to the tick Rhipicephalus microplus and the relationship with coat traits

This study evaluated the resistance of cattle of different genetic groups to the tick Rhipicephalus microplus and the relationship with traits of the animals' hair and coat. Cows of the Senepol×Nelore (SN), Angus×Nelore (AN) and Nelore (NX) genetic groups were submitted to four consecutive artificial infestations, at 14-day intervals, each one with approximately 20,000 tick larvae placed on the animals' lumbar region. From the 19th to 23rd day of each infestation five counts of the number of ticks were performed on each animal's left body side. The tick count data (TTC) were transformed into log(10) (n+1), and also into percentage of return (PR), where n is the total number of ticks counted at each infestation. Hair samples were collected 24h after the last infestation with flat-nosed pliers. Measures of the average hair length (HL), coat thickness (CT), number of hairs per cm(2) (NHCM2) and weight of the samples (SW) were obtained. Pearson's correlation coefficients were calculated within genetic group to measure association between PR and the hair and coat data. There was a significant difference among genetic groups for the number of ticks, with the AN group having higher counts than the SN and NX groups. For the hair and coat traits, the NX and SN groups had lower values of HL and SW than did the AN group. The SN genetic group had lower NHCM2 counts than the NX and AN groups. There were positive correlations between TTC and CT (P<0.05) and SW (P<0.05) in the SN group. No significant correlation was found for the AN genetic group (P>0.05).     

Reversible anesthesia in wild marine otters (Lontra felina) using ketamine and medetomidine.

Nine marine otters (Lontra felina) were anesthetized 15 times with a combination of ketamine (5.3 +/- 0.9 [range: 4.5-8.0] mg/kg) and medetomidine (53 - 9 [range: 45-80] microg/kg) i.m. by hand syringe for the placement of radiotransmitters. Times to initial effect and induction period ranged from 1.1 to 5.0 min and 1.8 to 5.4 min, respectively. Minor complications did occur, including mild hypothermia in six otters and severe hypoxemia in one otter. After 34 and 63 min, anesthesia was antagonized with atipamezole (226 +/- 29 [range: 179-265] microg/kg) and all otters recovered within 3.3-26.8 min.     

Cover Image,Volume 73, Issue 9

The cover image, by Frode Oppedal et al., is based on the Research Article Sea lice infestation levels decrease with deeper ‘snorkel’ barriers in Atlantic salmon sea‐cages, DOI: 10.1002/ps.4560 .

     

Occurrence of Raoiella indica Hirst (Acari,Tenuipalpidae) in the Southeast region of the state of Pará, Brazil

Journal of Plant Diseases and Protection - The red palm mite Raoiella indica Hirst attacks coconut, banana and açai trees. In 2007, the mite was recorded for the first time in South America....     

In vitro acaricidal activity of neem (Azadirachta indica) seed extracts with known azadirachtin concentrations against Rhipicephalus microplus

The effect of four extracts from neem seeds (Azadirachta indica) containing 2000, 5000, 9000 and 10,000 ppm of azadirachtin A (AZA), quantified by high-performance liquid chromatography (HPLC) and diluted to 1.25%; 2.5%; 5.0%; 10.0% and 12.8% was verified by in vitro tests with engorged females and larvae of the cattle tick Rhipicephalus microplus. The results from the bioassays with the engorged females showed that the main toxic effect of the extracts was reduction of the reproductive parameters, with a sharp drop in the number of eggs laid and the hatching rate, mainly when the extracts were diluted to 10.0% and 12.8%. The product effectiveness (PE) calculations for all the solutions tested showed that the AZA solution at 10,000 ppm (N10) was the most effective. However, statistical analysis of the PE data obtained for the proportional AZA concentrations in the different diluted extracts showed significance (P<0.05) of the effects included in the model (extract dilution, principle effect (classificatory) of the assay (extract) and the interaction between the two), indicating significant variations due to the dilution, the test and the interaction between the two factors in the tests with engorged females. For solutions N2, N5, and N9, it was not possible to estimate LC(90) values in the dilution range tested. The lowest LC(50) was observed for extract N5, and although extract N10 was the only extract for which the LC(90) could be estimated within the range tested, the LC(50) was higher than for N5 and N9. These results suggest that substances other than AZA present in the extracts influenced the efficacy, especially up to a certain LC range. In the tests with larvae, no mortality was observed, indicating zero effectiveness of all the extracts tested. The results of the tests with engorged females showed that the neem extracts had acaricide activity, inhibiting egg laying and the larval hatching rate. Complementary studies are necessary to develop new methods to isolate and/or identify other substances besides AZA contained in this plant, to enable using products made from it as acaricides.     

Vitrification of ovarian tissue of Brazilian North‐eastern donkeys (Equus asinus) using different cryoprotectants

The aim of this study was to assess a vitrification protocol for asinine ovarian tissue, to preserve preantral follicles using different cryoprotectant solutions, composed of various concentrations (EG 3 M or 6 M) of dimethyl sulfoxide or ethylene glycol isolate, or as a combination (DMSO 3 M + EG 3 M). Ten pairs of ovaries from Brazilian north‐eastern breed jennies were obtained through videolaparoscopy, and cortical fragments were submitted to a solid‐surface vitrification (SSV) using each cryoprotectant solution. The ovarian tissue was evaluated for follicular morphology and viability, DNA integrity (TUNEL technique) and the presence of nucleolar organizing regions in granulosa cells (AgNOR technique). After thawing, the percentage of normal preantral follicles was significantly reduced in the vitrified ovarian tissue fragments compared to the fresh control (p < 0.05). When comparing treatments, the use of DMSO 3 M (81.7 ± 37.5%), EG 3 M (83.7 ± 27.4%) and the combination of both DMSO 3 M + EG 3 M (81.8 ± 46.8%) allowed a greater percentage of follicular survival in contrast to DMSO 6 M (69.8 ± 16.5%) and EG 6 M (72.3 ± 18.0%; p < 0.05). When vitrified using the DMSO + EG combination, a higher percentage (62.5 ± 29.1%) of viable follicles (trypan blue) was observed in relation to the other vitrification treatments (p < 0.05). The TUNEL technique identified that all treatments tested showed DNA fragmentation in the follicular cells, except in the case of the DMSO 3 M + EG 3 M treatment. When evaluating the presence of NORs, no significant differences were observed in the amount of NORs between the fresh and vitrified groups using DMSO 3 M + EG 3 M (p > 0.05). We concluded that the combination DMSO 3 M + EG was more efficient for the vitrification of ovarian tissue taken from Equus asinus, allowing adequate preservation of PAFs morphology, viability, DNA integrity and cell proliferative capacity.     

Of mushrooms and chocolate trees: aetiology and phylogeny of witches' broom and frosty pod diseases of cacao

The troubled history of the two major diseases of the chocolate tree (Theobroma cacao) in South America, witches' broom and frosty pod, is reviewed, concentrating on critical aspects of the aetiology as well as the phylogeny of the causal agents. Both diseases are caused by sister species within the genus Moniliophthora, belonging to the Marasmiaceae family of mushrooms. The witches' broom pathogen, Moniliophthora perniciosa, evolved on the Amazonian side of the Andes and induces brooms not only in cacao and its relatives in the genera Theobroma and Herrania (Malvaceae), but also in species in the plant families Bignoniaceae, Malpighiaceae and Solanaceae, on which the mushrooms (basidiomata) are produced. Moniliophthora roreri, the type species of the genus, evolved as a pod pathogen on endemic Theobroma species on the western side of the northern Andean Cordillera. Because Moniliophthora was described originally as the asexual form of an unknown basidiomycete, the generic diagnosis is amended here to accommodate species with agaricoid basidiomata. In addition, the new variety M. roreri var. gileri is designated for the morphotype occurring on Theobroma gileri, in northwest Ecuador. Cytology studies indicate that the supposed conidia of M. roreri are, in fact, sexual spores (meiospores) and it is posited that the fruiting structure represents a much‐modified mushroom. Finally, based on preliminary data from pathogenicity testing, it is hypothesized that the true causal agent of both diseases is an as yet unidentified infectious agent vectored into the host by the fungus.     

Increase of tospoviral diversity in Brazil with the identification of two new tospovirus species, one from chrysanthemum and one from zucchini

ABSTRACT During a survey conducted in several different regions of Brazil, two unique tospoviruses were isolated and characterized, one from chrysanthemum and the other from zucchini. The chrysanthemum virus displayed a broad host range, whereas the virus from zucchini was restricted mainly to the family Cucurbitaceae. Double-antibody sandwich-enzyme-linked immunosorbent assay and western immunoblot analyses demonstrated that both viruses were serologically distinct from all reported tospovirus species including the recently proposed peanut yellow spot virus and iris yellow spot virus (IYSV) species. The nucleotide sequences of the nucleocapsid (N) genes of both viruses contain 780 nucleotides encoding for deduced proteins of 260 amino acids. The N proteins of these two viruses displayed amino acid sequence similarities with the previously described tospovirus species ranging from 20 to 75%, but they were more closely related to each other (80%). Based on the biological and molecular features, these viruses are proposed as two new tospovirus species, designated chrysanthemum stem necrosis virus (CSNV) and zucchini lethal chlorosis virus (ZLCV). With the identification of CSNV and ZLCV, in addition to tomato spotted wilt virus, groundnut ring spot virus, tomato chlorotic spot virus, and IYSV, Brazil harbors the broadest spectrum of tospovirus species reported.     

Atmospheric Deposition of Acidifying and Eutrophicating Substances in Dune Slacks

Water, Air, &; Soil Pollution - The atmospheric input of nitrogen and potantial acid, and the composition of the leachate from the topsoil layer are quantified for eight dune slack sites...