Lethal and Sublethal Effects of Single and Double Applications of Bacillus thuringiensis Variety kurstaki on Spruce Budworm (Lepidoptera: Tortricidae) Larvae
Bibliographic record
Abstract
We conducted laboratory experiments to examine the effects of single versus double exposures of spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) female larvae to various concentrations of a Bacillus thuringiensis variety kurstaki (Btk) commercial formulation (Foray 48B). Our main objective was to document the vulnerability to Btk and the sublethal responses of fifth-instar larvae that survived from a first ingestion of Btk during their fourth stadium and to compare them with insects treated either during their fifth or fourth stadium only. As reported in the literature, fifth-instar larvae were more vulnerable than fourth-instar larvae, but only at low and medium concentrations. Fifth-instar larvae that had survived Btk ingestion during their fourth stadium were more vulnerable to a high concentration of Btk and had a shorter feeding inhibition period than those that had not been exposed during their fourth stadium. Compared with a single treatment at the fourth stadium, a double exposure to Btk further reduced the population by 20-30%, depending on the concentration applied. The second treatment also induced another feeding inhibition period and increased larval development time by 14%. The impact of the different treatments on pupal weight depended on whether treated insects exhibited supernumerary instars. In the absence of developmental polymorphism, a higher concentration, a late, or a double exposure to Btk significantly reduced pupal weight.
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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".