The Role of the Bark Beetle, Hylastes ater (Coleoptera: Scolytidae), as a Sapstain Fungi Vector to Pinus radiata Seedlings: A Crisis for the New Zealand Forestry Industry?

The role of the bark beetle Hylastes ater in the re-establishment of Pinus radiata forest in New Zealand is discussed. H. ater was found to be a dominant factor in seedlings mortality in the first year following planting. However, seedling mortality is usually relatively low. In contrast, it was found the large numbers of seedlings were sub-lethally damaged by H. ater feeding attempts, particularly in high risk sites. High risk sites were identified as sites that were harvested during March and April (autumn) when the peak flight activity of H. ater occurred, and subsequently planted with P. radiata seedlings the following winter. H. ater was found to vector sapstain fungi to seedlings during feeding attempts, and a strong relationship between the severity of damage and presence of sapstain fungi was identified. The role of H. ater as a vector of these fungi and the potential implications to the New Zealand forest industry are discussed.     

Evaluation of PCR,IEF and ELISA techniques for the detection and identification of potato cyst nematodes from field soil samples in England and Wales

Effective management of potato cyst nematodes (PCNs) requires simple, rapid and accurate identification and quantification of field populations. Soil samples from a survey of 484 fields in potato rotations in England and Wales were used to compare the identification and quantification of PCNs using IEF, PCR, ELISA and bait plant tests. The cyst counts and bait plant test revealed that 64.3% of field samples contained PCNs. Bait plant tests increased the detection rate of PCNs in field samples by 4–6.4%. This means that some infestations are cryptic and would not normally be detected by standard counts. IEF, PCR and ELISA methods distinguished between Globodera rostochiensis and G pallida and were able to register mixed populations; however they were not in full agreement. All methods suggested that G pallida is the dominant species in the field samples tested. The PCR results indicated that 66% of field samples contained pure G pallida, 8% contained pure G rostochiensis and 26% contained mixtures of the two species. Estimates of the relative process times taken per sample in the PCR, IEF and ELISA techniques are given. © 2001 Society of Chemical Industry     

Characterization of residues in soybeans grown in soil treated with 1,3-dichloropropene soil fumigant

The metabolism of cis- and trans-1,3-dichloropropene (1,3-D) was studied in soybean plants grown in soil treated 24 days prior to planting with [U-¹⁴C]E- and Z-1,3-dichloropropene at 380 liters ha^?1. Isolation and identification of the ¹⁴C residue from soybean plants at 84 days (forage) and 176 days (mature) after application showed that no 1,3-dichloropropene or its putative metabolites, 3-chloroallyl alcohol and 3-chloroacrylic acid, could be detected in any of the tissues. The components of the ¹⁴C residue included major plant constituents (i.e. fatty acids, protein, pigments, organic acids, sucrose and other carbohydrates, and lignin).     

Impedimetric evaluation of compounds for antifungal activity versus Aspergillus niger

The procedure described utilized a microbial monitoring system (bactometer) to measure impedimetrically the inhibitory activity of known antifungal compounds (2-(thiocyanomethylthio)benzothiazole [TCMTB], 3-iodo-2-propynylbutyl carbamate [IPBC], chlorothalonil, tebuconazole, and copper-8-quinolinolate [Cu-8]) on growth of Aspergillus niger Teigh. in a liquid medium. The MIC values determined were based on the activity of the compounds to inhibit a change in the capacitance of the medium during a 96-h period after inoculation. The MIC values obtained with the bactometer were compared with MIC values derived from the inhibition of radial growth of A. niger on the same liquid medium solidified with agar. The MIC values for all the compounds tested were substantially lower when determined with the bactometer than on agar. The impedimetric evaluation of compounds for antifungal activity offers advantages of speed, sensitivity, and data collection.     

Congenital internal hydrocephalus in a quarter horse foal

Since the normal absorption of CSF occurs in the cerebral veins and venous sinuses, any obstruction to the normal flow and absorption of CSF will result in accumulation of CSF central to the site of obstruction. Such accumulation within the cranium is defined as hydrocephalus.A foal was presented with an enlarged and an abnormally-shaped skull, but with normal behavior. The filly's condition deteriorated. Radiographs showed a domeshaped cranial vault with compression of the frontal sinus region. Massive hydrocephalus with little normal cerebral tissue left was diagnosed with ultrasound.Surgery was attempted to relieve the pressure. Eventually the foal was euthanized. Post-mortem confirmed the radiographic and ultrasound diagnosis. Since there was a lack of demonstrable obstruction, the authors suspected the foal had suffered from the Arnold-Chiari syndrome.     

Effects of oxypolygelatin and dextran 70 on hemostatic variables in dogs

Objective To evaluate and compare coagulation variables following the administration of oxypolygelatin and dextran 70 to clinically healthy dogs. Study design Randomized cross‐over experimental study. Animals A total of eight healthy adult female Beagles aged 2–4 years old and weighing 11.8 ± 2.7 kg. Methods The dogs received a 15‐minute intravenous (IV) infusion of 5 mL kg^?1 oxypolygelatin or 10 mL kg^?1 6% dextran 70. Before (PRE) and at 2, 5, and 24 hours after administration, packed cell volume (PCV), total solids concentration (TS), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen concentration (FIB), platelet numbers (Plat), factor VIII coagulant activity (VIII:C), von Willebrand factor antigen concentration (vWf:Ag) and platelet function and buccal mucosal bleeding time (BMBT) were measured. Platelet function was assessed using aggregation and by measuring ATP release from aggregating platelets over 6 minutes, with 20, 10, and 5 µm ADP and 5 and 10 µg of collagen mL^?1 as platelet activation agonists. Results All baseline values were within our normal ranges, except for one dog that had low vWf:Ag PRE values prior to both dextran and oxypolygelatin administration. Following dextran and oxypolygelatin administration, the PCV and TP were significantly (p < 0.05) decreased. Plat, FIB, and vWf:Ag decreased, while BMBT and VIII:C increased following dextran administration. Dextran also caused a significant decrease in platelet aggregation in response to ADP. Oxypolygelatin caused a significant decrease in vWf:Ag, Plat, and FIB compared to PRE values. The total amount of ATP released, standardized to platelet number, did not vary significantly for either group at any sampling time from PRE values. No significant changes from PRE values were noted at any time in either group for PT or APTT. Conclusion At the doses administered, both dextran and oxypolygelatin can interfere with hemostatic variables in healthy dogs, but dextran's effect is more profound and prolonged when compared to oxypolygelatin. Clinical relevance Oxypolygelatin causes fewer hemostatic abnormalities when compared to dextran, making it a superior colloid for administration at the doses tested.     

Field efficacy of ivermectin plus praziquantel oral paste against naturally acquired gastrointestinal nematodes and cestodes of horses in North America and Europe

The efficacy of an oral formulation of ivermectin plus praziquantel in the reduction of nematode and cestode egg counts in horses was assessed in 273 horses under field conditions at 15 sites in North America (n = 6) and Europe (n = 9). Horses were confirmed by fecal examination to have natural infections of strongyles (100%) and tapeworms (76%). Replicates of four horses were formed at each site, and in each replicate three animals received ivermectin (0.2 mg/kg body weight) plus praziquantel (1 mg/kg body weight) oral paste and one animal remained untreated or received vehicle paste. Fecal samples were collected for fecal nematode and cestode egg counting before and 7, 8, 9, 14, 15, and 16 days after treatment. Horses treated with ivermectin plus praziquantel oral paste had significantly (P <.01) lower posttreatment strongylid and cestode egg counts (reductions of 98% or more) than controls. Combined site analyses revealed that 95% or 96% of the horses positive for cestode eggs before treatment that were treated with ivermectin plus praziquantel were negative for cestode eggs at each posttreatment fecal examination. No adverse reactions attributable to ivermectin plus praziquantel oral paste treatments were observed. The results of the studies demonstrated that ivermectin plus praziquantel paste was highly effective in reducing egg shedding by gastrointestinal nematodes and cestodes, and no adverse reactions were observed in horses treated under field conditions.     

Efficacy of extended pirlimycin therapy for treatment of experimentally induced Streptococcus uberis intramammary infections in lactating dairy cattle

Streptococcus uberis is an important cause of mastitis in dairy cows throughout the world, particularly during the dry period, around the time of calving, and during early lactation. Strategies for controlling S. uberis mastitis have not received adequate research attention and are therefore poorly defined and inadequate. Objectives of the present study were to evaluate the efficacy of extended therapy regimens with pirlimycin for treatment of experimentally induced S. uberis intramammary infections in lactating dairy cows during early lactation and to evaluate the usefulness of the S. uberis experimental infection model for evaluating antimicrobial efficacy in dairy cows. The efficacy of extended pirlimycin intramammary therapy regimens was investigated in 103 mammary glands of 68 dairy cows that became infected following experimental challenge with S. uberis during early lactation. Cows infected with S. uberis in one or both experimentally challenged mammary glands were randomly allocated to three groups, representing three different treatment regimens with pirlimycin, including 2-day (n = 21 cows, 31 mammary quarters), 5-day (n = 21 cows, 32 quarters), and 8-day (n = 26 cows, 40 quarters). For all groups, pirlimycin was administered at a rate of 50 mg of pirlimycin hydrochloride via intramammary infusion. A cure was defined as an experimentally infected mammary gland that was treated with pirlimycin and was bacteriologically negative for the presence of S. uberis at 7, 14, 21, and 28 days after treatment. Experimental S. uberis intramammary infections were eliminated in 58.1% of the infected quarters treated with the pirlimycin 2-day regimen, 68.8% for the 5-day regimen, and 80.0% for the 8-day regimen. Significant differences (P <.05) in efficacy were observed between the 2-day and 8-day treatment regimens. The number of somatic cells in milk decreased significantly following therapy in quarters for which treatment was successful in eliminating S. uberis. However, there was no evidence to suggest that extended therapy with pirlimycin resulted in a greater reduction in somatic cell counts in milk than the 2-day treatment. The S. uberis experimental infection model was a rapid and effective means of evaluating antimicrobial efficacy during early lactation at a time when mammary glands are highly susceptible to S. uberis intramammary infection.     

Isolates of Verticillium dahliae Pathogenic to Crucifers Are of at Least Three Distinct Molecular Types

ABSTRACT Diverse isolates of the soilborne wilt fungi Verticillium dahliae and V. albo-atrum were studied to understand the nature and origins of those infecting cruciferous hosts. All isolates from cruciferous crops produced microsclerotia, and the majority produced long conidia with a high nuclear DNA content; these isolates were divided into two groups by amplified fragment length polymorphism (AFLP) analysis. One group could be subdivided by other criteria such as rRNA sequences and mitochondrial DNA restriction fragment length polymorphism (RFLP) analysis. Two crucifer isolates were short spored and had a low nuclear DNA content. The results are consistent with the crucifer isolates being interspecific hybrids. The long-spored isolates are best regarded as amphihaploids (or allodiploids) with the AFLP groups probably each representing separate interspecific hybridization events. The short-spored crucifer isolates appear to be derived from interspecific hybrids and are here called 'secondary haploids'. Molecular evidence suggests that one parent in the crosses was similar to V. dahliae. The other parent of the amphihaploids seems to have been more similar to V. albo-atrum than to V. dahliae, but was distinct from all isolates of either species so far studied. The implications for the taxonomy of crucifer isolates are discussed and the use of the name V. longisporum, proposed elsewhere for just some of these isolates, is discouraged.