Sampling<i>Aphis glycines</i>(Homoptera: Aphididae) in Soybean Fields in Illinois
Bibliographic record
Abstract
The aphid Aphis glycines Matsumura, which was first observed in North America in 2000, is a pest of soybean, Glycine max L., in the United States and southern Canada. This study focused on the distribution and sampling of this aphid at two spatial scales: field and township. We sampled 14 soybean fields in each of two townships in Kendall and Champaign counties in Illinois on four sampling dates during the summers of 2001–2003. Generally, there was little synchrony of population dynamics (increases or decreases) across the fields in either township during the middle of the summers. There was significant field-to-field variability in mean number of aphids per plant. Thus, multiple fields must be sampled to accurately understand the infestation levels in a township. For Kendall Township in all years, drilled soybean fields always had the highest mean density at the second and third sampling dates, but fields with wide rows (0.61–0.76-m widths) had the highest mean density at the fourth date. However, row spacing had no significant influence on the mean density in most of the other analyses of variance. The probability of finding an infested field by mid-July when mean density in the township is less than two aphids per plant is 50% for Kendall County and 11% for Champaign County. Thus, at least two and 14 fields in Kendall and Champaign counties, respectively, must be sampled (50 plants per field) to have at least a 75% chance of finding a new invader in at least one infested field in a township during that period. Variance was related to mean number of aphids per plant, M, in a field by S2 = 6.39911 × M1.71779. This specific form of Taylor’s power law allowed us to calculate the appropriate sample sizes (plants/field) needed to obtain different levels of precision. Regression analysis showed no relationship between aphid density and distance from the field edge over the 50-m transects used in sampling. The relationship between the proportion of infested plants in a field, P, and mean aphid density, M, is represented by P = 1 − exp(−0.195764M). The proportion exceeds 0.99 for mean densities exceeding 24 aphids per plant in a field. Thus, our results suggest that aphids should be counted on 50 plants per field to obtain a reliable estimate of the population.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".