Ontogenetic shift from aposematism and gregariousness to crypsis in a Romaleid grasshopper
Bibliographic record
Abstract
Traits of chemically-defended animals can change as an individual grows and matures, and both theoretical and empirical evidence favour a direction of change from crypsis to aposematism. This study examines the suite of traits involved in an unusual opposite shift from aposematism to crypsis in a neotropical toxic-plant-feeding Romaleid grasshopper, Chromacris psittacus (Gerstaecker, 1873). Field surveys, behavioural observations and a rearing experiment compare host plant choice, aggregation, locomotion and thermoregulation between life history stages. Results showed that both nymphs and adults fed exclusively on a narrow range of Solanaceae plants, suggesting that the shift in defensive syndrome is not due to a change in chemical defense. Instead, nymphal aposematism appears linked to aggregation in response to plant-based selection pressures. Slow nymphal development suggests a cost to feeding on toxic plant compounds, and grouping could mitigate this cost. Grouping also increases conspicuousness, and hence can favour warning colourating in chemically-defended insects. The role of diet breadth in aposematism is poorly understood, and these results suggest how constraints imposed by feeding on toxic plants can generate bottom-up selection pressures shaping the adaptive suites of traits of chemically-defended animals.
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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 | 0.001 | 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".