Georeferenced reports of <i>Phenacoccus manihoti</i> on cassava in Asia (2008–2012).

<p><i>Notes</i>: Reports in bold correspond to specimens studied to verify identification key and were deposited at the entomological reference collection of the International Center for Tropical Agriculture (CIAT).</p

<i>P. manihoti</i> infestations and associated symptoms on cassava in Asia.

<p>A. <i>P. manihoti</i> populations at upper nodes. B. Heavy infestations and associated terminal shoot distortion. C. Stem deformation associated with <i>P. manihoti</i> infestations. Photo credits: A and B: S. Parsa; C: A. Winotai.</p

CLIMEX climatic suitability indices for <i>Phenacoccus manihoti</i> in Asia.

<p>Predictions used the CLIMOND interpolated climate database at 10′. A. Ecological index (EI), a measure of climatic suitability from 1–100. EI values greater than 20 indicate high risk of infestations. B. Cold stress, an index of mortality caused by intolerable cold. C. Heat stress, an index of mortality caused by intolerable heat. D. Wet stress, an index of mortality caused by rainfall. E. Number of generations per year <i>P. manihoti</i> can potentially complete at a given location.</p

Relationship between successive invasion phases and corresponding management options.

<p>Relationship between successive invasion phases and corresponding management options.</p

CLIMEX climatic suitability indices for <i>Phenacoccus manihoti</i> at selected locations.

<p>Predictions are based on the ecological index (EI), a measure of climatic suitability scaled from 1–100, for locations within CLIMEX's station database. The growth index captures conditions suitable for population growth and the wet stress captures mortality due to rainfall only. Predictions for Asuncion and Noqui correlate with <i>P. manihoti</i> seasonal dynamics reported by Löhr and Varela <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047675#pone.0047675-Lhr1" target="_blank">[2]</a> and Leuschner and Nwanze <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047675#pone.0047675-Leuschner1" target="_blank">[39]</a> respectively.</p

Temporal decay in the efficacy of insecticide treatments against Andean potato weevils (<i>Premnotrypes</i> spp.), as applied by farmers.

<p>The x-axis shows the parameter estimate ± SEM associated with the effect of a single insecticide application on the proportion of tubers infested with weevils (sqrt-transformed). The y-axis shows the month of the insecticide treatment.</p

Forward stepwise development of the global (least parsimonious) statistical model explaining Andean potato weevil infestations.

<p>The x-axis shows the progressive addition of explanatory variables in order of their contributions to lowering AIC. The y-axis shows cumulative reductions in AIC from the AIC associated with using only the mean to estimate infestations. The first dashed line shows the point where the addition of variables started to penalize the AIC, whereas the second dashed line shows the point where this penalty started to exceed two AIC values. The global model included all variables before the second dashed line.</p

Standardized predicted impacts of explanatory variables on Andean potato infestations.

<p>The model is initially set to predict infestations for a field with no pesticide applications and with mean (for continuous variables) or most common (for ordinal and categorical variables) values for all other explanatory variables. For continuous explanatory variables, bars reflect predicted changes in infestations in response to a one standard deviation increase in the explanatory variable. For ordinal explanatory variables, the bars reflect predicted changes in infestations in response to a single unit increase in the explanatory variable; except for the number of hillings, for which only a decrease could maintain predictions within observed bounds.To obtain multi-model predictions, parameter estimates were multiplied by their corresponding parameter weights. Hence, predicted effects are “attenuated” for explanatory variables with parameter weights smaller than 1.</p

Parameter estimates ± SEM for the best models predicting Andean weevil infestations based on local factors only (i.e. Best local), landscape factors only (i.e. Best landscape) or both local and landscape factors together (i.e. Best combined).

<p><i>Notes</i>: Lower AIC values suggest better model performance. The Akaike weight, <i>w</i>_i, is interpreted as the relative probability that a given model is the best in the set. The models included control variables for observer effects (not presented in the table).</p>*<p><i>P</i>≤0.05.</p>**<p><i>P</i>≤0.01.</p

Community knowledge worker assisting farmers with record-keeping activities associated with their potato harvest.

<p>The individual pictured in this manuscript has given written informed consent (as outlined in the PLoS consent form) to appear in the published photo. Photo credit: Soroush Parsa.</p