Preingestive Detection of Tannins by<i>Choristoneura fumiferana</i>(Lepidoptera: Tortricidae)
Bibliographic record
Abstract
Abstract The spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), is considered the most important pest threatening coniferous forests of eastern North America. Its major hosts are balsam fir [Abies balsamea (L.)], white spruce [Picea glauca (Moench) Voss], red spruce (Picea rubens Sarg.), and black spruce [Picea mariana (Mill.) Britton, Sterns and Poggenb.], all of which contain antiherbivore defensive compounds, including tannins. Tannins are known to act as feeding deterrents, digestibility reducers, and toxins in numerous insects and specifically to reduce growth and survival in the spruce budworm. Using two-choice feeding assays, we show that tannic acid deters spruce budworm feeding, whereas tannins extracted from white spruce and containing 97.8% condensed tannins stimulate it. Moreover, a dose-response relationship was demonstrated for both types of tannin. To our knowledge, this is the first report of a phagostimulatory role of condensed tannins in any insect. Tannic acid only deterred feeding when in solution with sucrose but remained undetected when in solution alone, whereas the condensed spruce tannins produced a positive response alone, and this response was increased by the addition of sucrose. Based on these results, we speculate that both types of tannins produce their respective effects through different mechanisms: tannic acid seems to interfere with sucrose detection, whereas spruce tannins can evidently stimulate feeding directly in this insect. For both types of tannins, the insects do not seem to be able to detect the 0.75% tannin concentration, suggesting a possible response threshold. Rearing insects on diets containing tannic acid revealed possible effects of aversion learning and of induction when tested in feeding assays with tannic acid and spruce tannins, respectively.
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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 | 0.000 | 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) | 0.001 | 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".