Technological Advances to Address Current Issues in Entomology: 2020 Student Debates

The 2020 Student Debates of the Entomological Society of America (ESA) were live-streamed during the Virtual Annual Meeting to debate current, prominent entomological issues of interest to members. The Student Debates Subcommittee of the National ESA Student Affairs Committee coordinated the student efforts throughout the year and hosted the live event. This year, four unbiased introductory speakers provided background for each debate topic while four multi-university teams were each assigned a debate topic under the theme ‘Technological Advances to Address Current Issues in Entomology’. The two debate topics selected were as follows: 1) What is the best taxonomic approach to identify and classify insects? and 2) What is the best current technology to address the locust swarms worldwide? Unbiased introduction speakers and debate teams began preparing approximately six months before the live event. During the live event, teams shared their critical thinking and practiced communication skills by defending their positions on either taxonomical identification and classification of insects or managing the damaging outbreaks of locusts in crops.     

A demographic survey of unwanted horses in Ireland 2005-2010

Background

The Irish Horse Industry expanded during the Celtic Tiger boom years, then contracted in the current economic recession. High value horses were traditionally controlled through sale at public auction, private sales and sales to dealers; these are now also being reduced by decreases in production (> 40%), and increases in retirement, re-homing, euthanasia and disposal through Category 2 plants and abattoirs. The absence or banning of horse abattoirs has been shown to have very significant welfare social and economic consequences in the USA. This study described the currently available data on the demographics of unwanted horses in Ireland from 2005 to 2010.

Results

The majority of horses euthanised by practicing veterinarians are destroyed on medical grounds but the number euthanised at the request of welfare groups and the state, as well as welfare related calls and the number of horses involved in these calls and subsequent visits is increasing reflecting the increasing involvement of the veterinary profession in equine welfare. Welfare groups have limited resources and do not have a tradition of recording data, but they too have reported increasing calls, visits and numbers of horses per visit. Welfare groups provide significant service to equine welfare and the community. Local Authorities report similar trends. Over 300 horses were found dead or required immediate or subsequent euthanasia following welfare group and local authority visits in 2010, which is of national concern. The majority of local authority interfaces with unwanted horses are with urban (60%) rather than rural (40%) horses. Mortality figures are poor indicators of non-fatal neglect. More horses were admitted into the care of local authorities than welfare groups, reflecting significant state and taxpayer investment in the control of low value horses. Category 2 plants and abattoirs represent a significant state investment in licensing and control in the national interest. Abattoirs provide an increasingly important and essential service for the disposal of unwanted horses. Despite the increase in unwanted horses, Ireland is a minority contributor to the EU slaughter total.

Conclusions

There is a need for annual demographic data compilation and review of the numbers of unwanted horses and ponies within the horse industry to assist policy makers and legislators.     

Density‐dependent growth and survival in salmonids: Quantifying biological mechanisms and methodological biases

Understanding the complex variation in patterns of density‐dependent individual growth and survival across populations is critical to adaptive fisheries management, but the extent to which this variation is caused by biological or methodological differences is unclear. Consequently, we conducted a correlational meta‐analysis of published literature to investigate the relative importance of methodological and biological predictors on the shape and strength of density‐dependent individual growth and survival in salmonids. We obtained 160 effect sizes from 75 studies of 12 species conducted between 1977 and 2019 that differed in experimental approach (sensu Ecological Monographs, 54, 187–211; 65 laboratory experiments, 60 observational field studies, and 35 field experiments). The experimental approach was the strongest factor influencing the strength of density dependence across studies: density‐dependent survival was stronger than growth in field observational studies, whereas laboratory experiments detected stronger density‐dependent growth than survival. The difference between density‐dependent growth and survival was minimal in field experiments, and between lotic and lentic habitats. The shape of density dependence (logarithmic, linear, exponential or density‐independent) could be predicted with 66.7% accuracy based solely on the experimental approach and the density gradient (highest/lowest*100) of the study. Overall, the strength and shape of density dependence were primarily influenced by methodological predictors, while biological factors (predator presence, food abundance, and species) had predictable but modest effects. For both empirical studies and adaptive fisheries management, we recommend using field experiments with a density gradient of at least 470% to detect the proper shape of the density‐dependent response, or accounting for potential biases if observational or laboratory studies are conducted.     

Rapid pneumococcal evolution in response to clinical interventions

Epidemiological studies of the naturally transformable bacterial pathogen Streptococcus pneumoniae have previously been confounded by high rates of recombination. Sequencing 240 isolates of the PMEN1 (Spain(23F)-1) multidrug-resistant lineage enabled base substitutions to be distinguished from polymorphisms arising through horizontal sequence transfer. More than 700 recombinations were detected, with genes encoding major antigens frequently affected. Among these were 10 capsule-switching events, one of which accompanied a population shift as vaccine-escape serotype 19A isolates emerged in the USA after the introduction of the conjugate polysaccharide vaccine. The evolution of resistance to fluoroquinolones, rifampicin, and macrolides was observed to occur on multiple occasions. This study details how genomic plasticity within lineages of recombinogenic bacteria can permit adaptation to clinical interventions over remarkably short time scales.     

Classification of porcine reproductive and respiratory syndrome virus in Ontario using Bayesian phylogenetics and assessment of temporal trends

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important swine viruses globally, including in Ontario, Canada. Understanding the evolution and relation of the various PRRSV genotypes in Ontario can provide insight into the epidemiology of the virus. The objectives of this study were to i) describe the variability of PRRSV genotypes in Ontario swine herds, and ii) evaluate possible groupings based on PRRSV genomic data. Virus open reading frame 5 (ORF-5) sequences collected from 2010 to 2018 were obtained from the Animal Health Laboratory, University of Guelph and Bayesian phylogenetic models were created from these. The PRRSV population of Ontario was then categorized into 10 distinct clades. Model comparisons indicated that the model with a constant population assumption fit the data best, which suggests that the net change in the PRRS virus variation of the entire population over the last decade was low. Nonetheless, viruses grouped into individual clades showed temporal clustering during distinct time intervals of the entire study period (P < 0.01).