Cold Tolerance and Overwintering Physiology of the Salvinia Weevil (Cyrtobagous salviniae): Improving the Biological Control of Giant Salvinia in Temperate Louisiana

Cyrtobagous salviniae is widely used for biological control of Salvinia molesta. Despite success in tropical and subtropical regions, the effectiveness of C. salviniae on S. molesta is inconsistent in temperate regions, indicating the need for a better understanding of the thermal biology of this agent. The objectives of this study were to compare cold tolerance of C. salviniae populations from the temperate native range and Louisiana, and characterize the overwintering physiology and population dynamics of C. salviniae in Louisiana. Surveys of the Lower Paraná-Uruguay Delta resulted in the first record of C. salviniae in Uruguay, and revealed the most southern distribution of this species in Argentina and Uruguay. Survival at 0°C was 1.5-times greater, chill coma recovery time was 1.8-times faster, and SCP was 1.2-times lower in the Argentine population compared to the Louisiana population. These findings show that the Argentine provenance should be considered for managing S. molesta in temperate regions. Besides host range tests, cross breeding between the Louisiana and Argentine populations should be investigated to determine the life histories of any possible hybrid. Laboratory assays demonstrated phenotypic plasticity in the cold tolerance of populations from central and southern Louisiana when acclimated to winter conditions. Survival at 0°C was 1.8- and 1.7-times greater, critical thermal minimum was 1.2- and 1.3-times lower, and chill coma recovery time was 2.7- and 1.5-times faster in the winter treatments compared to summer treatments, for both populations (central and south, respectively). Seasonal changes in reproductive status, fat body, and water content were evident from the field study, and are speculated to contribute to the overwintering success of adults at both sites. Adult and larval densities showed that populations were most vulnerable in the late winter/early spring, presumably when water temperatures and host plant quality have not yet recovered. Seasonal monitoring of the physiological status and population dynamics should be conducted to improve the timing of releases and predicting the success of S. molesta control. In conclusion, the management of S. molesta in northern Louisiana should incorporate releases of cold tolerant populations, and seasonal monitoring of physiology and population dynamics of C. salviniae

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

It Takes a Village: The Role of Counselling Psychology in Advancing Health and Wellness in a Faculty of Education

Counselling psychology departments have historically been situated within Faculties of Education rather than Departments of Psychology. These placements within Faculties of Education have often led to confusion as to what the role of counselling psychology is, and how it relates to education. In this paper, we argue that there is an opportunity for counselling psychologists to impact and be impacted by their location in Faculties of Education. This paper offers an exemplar of how a counselling psychology department informed and impacted a culture of wellness within a Faculty of Education and also within the greater university culture, at the University of Calgary. Through partnership with other faculties and community partners, the efforts of counselling psychology began to impact other systems, which in turn influenced Bachelor of Education teacher preparation at the post-secondary level. Through collaboration with multiple partners and with the support of the Faculty of Education, a mandatory course on health and wellness was introduced to the Bachelor of Education curriculum. Perspectives of a counselling psychologist, faculty of education administrator, a community partner, and former counselling psychology graduate student are highlighted in this paper, with the intention of demonstrating how collaborations between two seemingly distinct disciplines can be mutually beneficial to the university, students, faculty, and also the greater community

An Economical Custom-Built Drone for Assessing Whale Health

Drones or Unmanned Aerial Vehicles (UAVs) have huge potential to improve the safety and efficiency of sample collection from wild animals under logistically challenging circumstances. Here we present a method for surveying population health that uses UAVs to sample respiratory vapor, ‘whale blow,' exhaled by free-swimming humpback whales (Megaptera novaeangliae), and coupled this with amplification and sequencing of respiratory tract microbiota. We developed a low-cost multirotor UAV incorporating a sterile petri dish with a remotely operated ‘blow' to sample whale blow with minimal disturbance to the whales. This design addressed several sampling challenges: accessibility; safety; cost, and critically, minimized the collection of atmospheric and seawater microbiota and other potential sources of sample contamination. We collected 59 samples of blow from northward migrating humpback whales off Sydney, Australia and used high throughput sequencing of bacterial ribosomal gene markers to identify putative respiratory tract microbiota. Model-based comparisons with seawater and drone-captured air demonstrated that our system minimized external sources of contamination and successfully captured sufficient material to identify whale blow-specific microbial taxa. Whale-specific taxa included species and genera previously associated with the respiratory tracts or oral cavities of mammals (e.g., Pseudomonas, Clostridia, Cardiobacterium), as well as species previously isolated from dolphin or killer whale blowholes (Corynebacteria, others). Many examples of exogenous marine species were identified, including Tenacibaculum and Psychrobacter spp. that have been associated with the skin microbiota of marine mammals and fish and may include pathogens. This information provides a baseline of respiratory tract microbiota profiles of contemporary whale health. Customized UAVs are a promising new tool for marine megafauna research and may have broad application in cost-effective monitoring and management of whale populations worldwide

Potential for negative interactions between successful arthropod and weed biological control programs: A case study with Lilioceris species

Successful biological control programs can have landscape-level effects on the management of intractable arthropod pests and weeds, improving ecosystem services and reducing both management costs and the widespread use of pesticides. However, biotic resistance can prevent biological control agents from establishing or limit their efficacy. We assessed the potential for biological control agents of the pest Lilioceris lilii, the lily leaf beetle, to attack L. cheni, a weed biological control agent for Dioscorea bulbifera, air potato. Both the suite of parasitoid biological control agents and L. cheni are contributing to the successful management of their respective targets. Thus, negative interactions between these species could potentially disrupt two effective biological control programs if range overlap occurs. Choice and no-choice tests were conducted with all three parasitoid species and the target and non-target beetles, and a phylogenetic tree was constructed to assess the relatedness of the Lilioceris species. The parasitoids displayed a clear preference for their host, L. lilii, and did not successfully parasitize L. cheni. Although interference between arthropod and weed biological control programs is not likely to be a common occurrence, practitioners in both subdisciplines should be cognizant of this possibility as new agents are developed

Shoot dimorphism enables Sequoia sempervirens to separate requirements for foliar water uptake and photosynthesis.

PremiseTrees in wet forests often have features that prevent water films from covering stomata and inhibiting gas exchange, while many trees in drier environments use foliar water uptake to reduce water stress. In forests with both wet and dry seasons, evergreen trees would benefit from producing leaves capable of balancing rainy-season photosynthesis with summertime water absorption.MethodsUsing samples collected from across the vertical gradient in tall redwood (Sequoia sempervirens) crowns, we estimated tree-level foliar water uptake and employed physics-based causative modeling to identify key functional traits that determine uptake potential by setting hydraulic resistance.ResultsWe showed that Sequoia has two functionally distinct shoot morphotypes. While most shoots specialize in photosynthesis, the axial shoot type is capable of much greater foliar water uptake, and its within-crown distribution varies with latitude. A suite of leaf surface traits cause hydraulic resistance, leading to variation in uptake capacity among samples.ConclusionsShoot dimorphism gives tall Sequoia trees the capacity to absorb up to 48 kg H2 O h-1 during the first hour of leaf wetting, ameliorating water stress while presumably maintaining high photosynthetic capacity year round. Geographic variation in shoot dimorphism suggests that plasticity in shoot-type distribution and leaf surface traits helps Sequoia maintain a dominate presence in both wet and dry forests

Shoot dimorphism enables Sequoia sempervirens to separate requirements for foliar water uptake and photosynthesis

Premise Trees in wet forests often have features that prevent water films from covering stomata and inhibiting gas exchange, while many trees in drier environments use foliar water uptake to reduce water stress. In forests with both wet and dry seasons, evergreen trees would benefit from producing leaves capable of balancing rainy-season photosynthesis with summertime water absorption. Methods Using samples collected from across the vertical gradient in tall redwood (Sequoia sempervirens) crowns, we estimated tree-level foliar water uptake and employed physics-based causative modeling to identify key functional traits that determine uptake potential by setting hydraulic resistance. Results We showed that Sequoia has two functionally distinct shoot morphotypes. While most shoots specialize in photosynthesis, the axial shoot type is capable of much greater foliar water uptake, and its within-crown distribution varies with latitude. A suite of leaf surface traits cause hydraulic resistance, leading to variation in uptake capacity among samples. Conclusions Shoot dimorphism gives tall Sequoia trees the capacity to absorb up to 48 kg H2O h−1 during the first hour of leaf wetting, ameliorating water stress while presumably maintaining high photosynthetic capacity year round. Geographic variation in shoot dimorphism suggests that plasticity in shoot-type distribution and leaf surface traits helps Sequoia maintain a dominate presence in both wet and dry forests.ISSN:1914-2016:ISSN:0002-912