Economic thresholds for <i>Hypera nigrirostris</i> (Coleoptera: Curculionidae) in red clover seed production from on-farm trials
Bibliographic record
Abstract
Red clover, Trifolium pratense L., is a perennial forage legume grown for seed production in Western Canada, contributing significantly to regional agricultural economies. The lesser clover leaf weevil, Hypera nigrirostris Fab. (Coleoptera: Curculionidae), is a key pest of red clover seed crops, with larval feeding capable of reducing seed yields by up to 50%. Despite its impact, no economic thresholds (ET) currently exist to guide insecticide application for this pest. As a result, prophylactic treatments are used that increase production costs, increase the potential for insecticide resistance, and pose risks to pollinators, which are essential for red clover seed production. This study established a quantitative relationship between larval density and red clover seed yield under field conditions and used these data to develop economic injury levels (EIL) and practical ETs across a range of seed price scenarios. Yield losses were strongly associated with increasing larval densities, and thresholds varied with changing economic conditions. These resulting thresholds provide the first data-driven guidance for managing H. nigrirostris in North American red clover seed systems, offering a foundation for cost-effective, pollinator-conscious pest management strategies.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".