Ruling out a host-range expansion as the cause of the unpredicted non-target attack on tagasaste (Chamaecytisus proliferus) by Bruchidius villosus

Scotch broom (Cytisus scoparius) is a woody shrub of European origin that is an invasive weed in New Zealand. Bruchidius villosus was released in New Zealand in 1986 as a biological control agent of Scotch broom, after tests indicated that it was specific to this species. However, in 1999, B. villosus was discovered developing in the seeds of an unpredicted host, tagasaste or tree lucerne (Chamaecytisus proliferus). Although the original choice tests carried out in quarantine failed to predict acceptance of C. proliferus by ovipositing females, the current population in New Zealand clearly finds this species an acceptable host. An investigation of the original host-testing procedures revealed a number of possible limitations in the tests conducted in the 1980s. Concerns that a host-range expansion might have occurred in a weed biological control agent led to this study in which beetles from the original population (Silwood Park, United Kingdom) were reimported and the original handling and host choice tests were replicated. Despite showing a strong preference for Scotch broom, the beetles tested in this study accepted C. proliferus for oviposition. These results allow us to rule out the possibility that a hostrange expansion has occurred

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Use of models and phenological forecasting in applied entomology

Although experienced modellers are usually aware of the dangers and benefits of the use of models in applied entomology, many scientists who may use models are not. Some remain sceptical that models serve any useful purpose, whereas others have unrealistic expectations about the information that models can provide concerning a particular problem. Here, the definition of a model is reviewed, a brief history of model use in general ecology is presented, and the limitations of uses of models in applied entomology are discussed. Published research concerning insect development rate or in particular, phenology models, shows that the effect of fluctuating temperature and rate summation on nonlinear and linear model predictions is not well-understood. The influence of the diurnal range of the temperature regime on the rate summation effect, and the interaction between the rate summation and the mathematical structure of a particular development rate model, are clearly demonstrated. This study shows that the selection of a development rate function for prescriptive use based on closeness of fit to developmental data from constant temperature experiments is meaningless. Neither should selection be based on how well a model derived from constant temperature experiments predicts insect development measured under a narrow range of fluctuating temperatures. Theoretical reasons why a nonlinear model fitted directly to rates observed under variable temperature laboratory or field data is inappropriate for subsequent prediction, are clearly demonstrated. An appropriate technique that calculates instantaneous development rate functions from fluctuating temperature development time observations is tested with hypothetical data. The technique failed to give reasonable estimates of the parameters of the instantaneous development rate function that generated the hypothetical data. Historical data of spring migration of the damson-hop aphid, Phorodon humuli (Shrank) recorded at Wye, Kent, and Rosemaund, Herefordshire; and phenology of overwintering host plant flowering recorded at East Malling, Kent, in England, were examined for possible associations. Relationships between mean temperature over a phenophase interval defined by flowering phenology of two overwintering host species of plum and the start of migration of P. humuli, versus the reciprocal of days over the interval, were significant for both sites. Predictive sample reuse (PSR) methodology was used to validate the potential of derived models to predict the start of migration of P. humuli at the two sites. The predictive performance of the host plant flowering-aphid migration phenology models derived in this study was compared with that of other methods that use historical field data to predict insect life cycle events. The host plant flowering - aphid migration phenology models gave the best prediction of the start and 50% migration at Wye based on the criterion of lowest absolute mean error of the PSR residuals. The value of using historical data of host plant and insect phenology to establish a biologically meaningful starting point for both the construction and application of predictive models of insect population events is illustrated. The desirability of comparing the performance of alternative phenology models that may be used for prescriptive use is discussed

Null-model validation of MLP input contribution analysis in ecology

A method is presented for applying a null-model analysis to the verification of the significance of the input neurons of Multi-Layer Perceptrons (MLP). This method was applied to a problem from ecology, namely the establishment of invasive insect pest species. Previous work has described how the MLP were trained to predict species establishment from climate data, and to identify which climatic factors are significant. The null-model analysis method described here was used to validate these predictions.Michael J. Watts and S. P. Worne

Being prepared: ecological informatics and computational intelligence methods applied to invasive insect risk assessment

S. P. Worner, M. J. Watts, J. P. W. Pitt and M. Gevre

Neuro-computing methods as aids to assessing the invasion potential of alien insects

Worner, S. P., Watts, M.J., Gevrey, M. and Pitt, J.http://www.intecol.net/info-esk/IX-Montreal/9-montreal.ht

Determining factors that influence the dispersal of a pelagic species: A comparison between artificial neural networks and evolutionary algorithms

D.R. Pontin, S. Schliebs, S.P. Worner, M.J. Watt