Mortality and infection of wireworm, Agriotes obscurus [Coleoptera: Elateridae], with inundative field applications of Metarhizium anisopliae

In an attempt to cause fatal infection of wireworm Agriotes obscurus [Coleoptera: Elateridae], Metarhizium anisopliae was applied in the field as factorial combinations of conidia formulated as granules at 3.68 g granules or 1.25 x 1010 cfu per 196 cm2 (6.38 x 107 conidia cm-2), as conidia mixed with soil at 1.26 x 1010 cfu per 2.986 cm3 soil (4.22 x 106 conidia cm-3 soil), and as conidia-coated wheat seed (100 wheat seeds or 4.16 x 109 cfu per 196 cm2 = 2.12 x 107 conidia cm-2). The treatments resulted in a significantly greater number of mycosed wireworms compared with the control over and during five sampling periods. Significant differences in total wireworm mortality and mycosed wireworms in the field occurred at any time ranging from 15 to 82 d following treatment. The treatments also caused a reduction in the number of wireworms found in the cores, implying that they had a repellent effect. Latent infection of wireworms became apparent after living wireworms from the field treatments died following incubation under laboratory conditions, in numbers significantly greater than the control. This study showed that M. anisopliae can be applied in the field and infect and kill wireworms, but only at concentrations exceeding 4 x 106 conidia cm-3 with the subject isolate, wireworm species, and field conditions used in this study.Dans une tentative d'infecter mortellement le ver fil de fer Agriotes obscurus [Coleoptera: Elateridae], le Metarhizium anisopliae a été appliqué au champ selon des combinaisons factorielles d'une formulation granulaire de conidies à 3,68 g de granules ou 1,25 x 1010 ufc par 196 cm2 (6,38 x 107 conidies cm-2), de conidies mélangées à du sol à 1,26 x 1010 ufc par 2,986 cm3 de sol (4,22 x 106 conidies cm-3 de sol) et de graines de blé enrobées de conidies (100 graines de blé ou 4,16 x 109 ufc par 196 cm2 = 2,12 x 107 conidies cm-2). Pendant cinq périodes d'échantillonnage, un nombre significativement plus grand de vers fil de fer mycosés a été observé pour les traitements comparativement au témoin. Des différences significatives en termes de mortalité totale des vers fil de fer et de vers fil de fer mycosés au champ sont apparues à toutes les périodes, variant de 15 à 82 j après le traitement. Les traitements ont aussi réduit le nombre de vers fil de fer trouvés dans le cylindre central, ce qui indique qu'ils ont eu un effet répulsif. L'infection latente des vers fil de fer s'est manifestée lorsque des spécimens vivants provenant des traitements au champ sont morts après incubation en laboratoire, en nombres significativement plus élevés que ceux provenant du témoin. Les résultats démontrent que le M. anisopliae peut être utilisé au champ et peut infecter et tuer les vers fil de fer, mais seulement à des concentrations excédant 4 x 106 conidies cm-3 en utilisant l'isolat, le ver fil de fer, ainsi que les conditions décrites dans la présente étude

Fungal entomopathogens: new insights on their ecology

An important mechanism for insect pest control should be the use of fungal entomopathogens. Even though these organisms have been studied for more than 100 y, their effective use in the field remains elusive. Recently, however, it has been discovered that many of these entomopathogenic fungi play additional roles in nature. They are endophytes, antagonists of plant pathogens, associates with the rhizosphere, and possibly even plant growth promoting agents. These findings indicate that the ecological role of these fungi in the environment is not fully understood and limits our ability to employ them successfully for pest management. In this paper, we review the recently discovered roles played by many entomopathogenic fungi and propose new research strategies focused on alternate uses for these fungi. It seems likely that these agents can be used in multiple roles in protecting plants from pests and diseases and at the same time promoting plant growth

Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users

Use of biological control against arthropod pests in Canadian greenhouse crop production

Greenhouse horticultural production currently represents an important and growing sector of Canada's food and plant production systems. Since 2006, the value of greenhouse vegetable crops in Canada exceeds that of field grown crops, signaling an important shift in the way food is cultivated in the country. While many factors have contributed to this change, a major area of innovation includes the discoveries and advances made in the development of commercial greenhouse production systems as well as the integration of biological control strategies for sustainable pest management. With this focus, this review offers a brief overview of the Canadian greenhouse industry, including a descriptive list of commonly used biological control organisms, as well as the role Canadian research has played in the development of these agents. We also address the threats that Canadian greenhouse producers face by invasive pests and the complications these have created for the commercialization of novel biological control agents. This information may serve as a guide for the development of parallel technologies and tools in other parts of the world where greenhouse production is expanding

Anaerobic bacteria isolated from the alimentary canals of alfalfa leafcutting bee larvae

Microorganisms were isolated from the alimentary canals of third-instar alfalfa leafcutting bee (Megachile rotundata) larvae under strict anaerobic conditions. In all 3 years of the study, small populations (8.0 colony-forming units per gut) of a limited number of bacterial taxa (primarily the facultatively anaerobic bacteria Paenibacillus macerans, Bacillus licheniformis, B. brevis, B. mycoides and P. polymyxa) were isolated. With the exception of three isolates of Clostridium longisporum recovered in 1993, no obligate anaerobic bacteria were isolated. The small size of populations and the inconsistency of recovery of bacteria in different years suggest that anaerobic microorganisms are not common inhabitants of leafcutting bee larval guts. Consequently they could not have a significant impact on the ecology of the alimentary canal nor influence the development of chalkbrood disease caused by the entompathogenic fungus, Ascosphaera aggregata. © Inra/DIB/AGIB/Elsevier, Pari

Infection by Beauveria Bassiana of Leptinotarsa Decemlineata Larvae as a Consequence of Fecal Contamination of the Integument Following Per Os Inoculation

A study ofper os inoculated larvae was undertaken to determine if the entomopathogenic fungus,Beauveria bassiana, is able to infect the Colorado potato beetle,Leptinotarsa decemlineata, via the alimentary tract. Surface orper os inoculated larvae which were immediately surface sterilized post inoculation did not succumb to infection, whereas those larvae not sterilized became infected. Histological studies of fed or starved, agnotobiotic (with microbial flora) and axenic larvae revealed that conidia can germinate in the gut regardless of the presence of gut microflora. However, infection via the alimentary tract was never observed in fed larvae and only noted in a single starved individual. It is concluded that infections ofper os inoclated larvae occurred after surface contamination of the integument by viable conidia contained in the frass. The rate of food passage through the gut is probably important in preventingper os infections

Carbon metabolism of Beauveria bassiana may be related to virulence against Plutella xylostella and Leptinotarsa decemlineata

Fermentation of 49 carbohydrates and oxidation and assimilation of 96 substrates were examined for ten Beauveria bassiana isolates. Principal component analysis indicated that there are significant differences among isolates for utilization of some substrates. Esculine and D- glucose were positively fermented by all isolates. Isolates were grouped into four clusters on the basis of hierarchial analysis of 96-hr reaction data. Using canonical variate analysis, it was determined that N-acetyl glucosamine fermentation and β-cyclodextrin oxidation were strongly and positively correlated with pathogenicity of isolates against diamondback moth, Plutella xylostella and Colorado potato beetle, Leptinotarsa decemlineata. In contrast, Sebacic acid assimilation was negatively correlated to virulence against these insects