This study investigated the inßuence of different humidity levels on percentage of infection by Beauveria bassiana (Balsamo) Vuillemin (Hyphomycetes) (Botanigard EmulsiÞable Suspension formulation) on greenhouse insect and mite pests, and their commercially available biological control agents. The target insect and mite species were sprayed with B. bassiana and evaluated in petri dish trials under controlled environment conditions, on cucumber leaves under greenhouse crop conditions, and under fully sprayed greenhouse conditions. Results of this study showed that in petri dish trials, a humidity of 97.5% RH resulted in signiÞcantly higher percentage of infection (60 Ð 88.8%), while at 75 and 80% RH only 15.3Ð 43.9% of the pest insects were infected. On leaf surfaces, the differences in ambient humidity did not cause as great of variations in percentage of infection as in the petri dish trials. Increasing greenhouse humidity by 15% RH caused an increase of 17Ð25% in percentage of infection. Under high humidity conditions, whole greenhouse sprays with B. bassiana successfully suppressed populations of Frankliniella occidentalis (Pergande) and Trialeurodes vaporariorum (Westwood). Tetranychus urticae Koch was not infected by B. bassiana at sig-niÞcant levels in any of the trials. Predatory mites can be used with B. bassiana, while adult Orius insidiosus (Say), Aphidius colemani Viereck, and Dacnusa sibirica Telenga are not recommended to be introduced during the application of B. bassiana. Encarsia formosa Gahan, Eretmocerus eremicus (Rose and Zolnerowich), and Aphidoletes aphidimyza (Rondani) need to be used with caution when B. bassiana is applied.

Aims:  Isolate and characterize water enterococci from the South Nation River drainage basin, an area dominated by agriculture. Methods and Results:  A total of 1558 enterococci were isolated from 204 water samples from the South Nation River obtained over a 3‐year period. PCR was used to identify isolates to the species level and characterize them for carriage of 12 virulence determinants. Antibiotic resistance was evaluated phenotypically. Enterococcus faecalis (36·4%), Enterococcus faecium (9·3%) and Enterococcus durans (8·5%) were the major enterococci species isolated. Enterococci carrying more than two virulence determinants were more frequently detected in the summer (59·6%) than in other seasons (≤37·6%). Very few isolates (≤2·0%) were resistant to category I antibiotics ciprofloxacin and vancomycin. Conclusions:  Comparison of major water enterococci species with major faecal enterococci species obtained from various host groups (human, domesticated mammals and birds, wildlife) in this drainage basin suggest that water enterococci may have varied faecal origins. The low level of antibiotic resistance among enterococci suggests that dispersion of antibiotic resistance via waterborne enterococci in this watershed is not significant. Significance and Impact of the Study:  The data obtained in this study suggests that water enterococci in the SNR have a faecal origin and that their potential impact on public health regarding antibiotic resistance and virulence determinants is minimal.

The success of the necrotrophic fungus Sclerotinia sclerotiorum is largely dependent on its major virulence factor, oxalic acid (OA). Virulence is lost in transgenic plants that express OA degrading enzymes, e.g. oxalate oxidase (OxO). The histopathology of S. sclerotiorum infection and OA accumulation was examined in a transgenic soybean line over-expressing OxO (OxO-OE) and its isogenic parent (WT). In situ flower inoculation showed that the OxO-OE plants were highly resistant to the pathogen while the WT parents were susceptible. This difference in resistance was not apparent in the floral tissues, as aggressive hyphal activity was similar on both hosts, showing that high OxO activity and low OA accumulation in OxO-OE was not a deterrent. However, the process of fungal infection on excised leaf tissue differed on the two hosts. Primary lesions developed and showed similar severe ultrastructural damage on both hosts but rapid lesion expansion (colonization) proceeded only on the WT, concomitant with OA accumulation. Oxalic acid rose in OxO-OE 1 day post-inoculation and did not change over the following 3 days, showing that colonization can be blocked by maintaining low levels of OA. However, OxO degradation of OA did not deter initial host penetration and primary lesion formation. This shows that OA, the major virulence factor of S. sclerotiorum, is critical for host colonization but may not be required during primary lesion formation, suggesting that other factors are contributing to the establishment of the primary lesion.

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