A HRM Assay for Rapid Identification of Members of the Seedcorn Maggot Complex (<i>Delia florilega</i>and<i>D. platura</i>) (Diptera: Anthomyiidae) and Evidence of Variation in Temporal Patterns of Larval Occurrence
Bibliographic record
Abstract
The seedcorn maggot Delia platura (Meigen), and the bean seed maggot Delia florilega (Zetterstedt) can cause considerable feeding damage to a wide range of cultivated crops. The recent discovery of two distinct genetic lines of D. platura, each with a unique distribution pattern overlapping only in eastern Canada, suggests the presence of a new cryptic species for the group. The reliable identification of the three species/lines in the seedcorn maggot complex is crucial to our understanding of their distribution, phenology, and respective contribution to crop damage as well as to the development of specific integrated pest management approaches. As these taxa are morphologically indistinguishable in the immature stages, we developed a high-resolution melting PCR (HRM) assay using primers amplifying a variable 96-bp PCR product in the CO1 mitochondrial gene for rapid and economical identification of specimens. The three species/lines exhibited distinguishable melting profiles based on their different Tm values (between 0.4 and 0.9°C) and identification results based on HRM and DNA sequencing were congruent for all specimens in the validation data set (n = 100). We then used the new, highly sensitive HRM assay to identify survey specimens from the seedcorn maggot complex collected in Quebec, Canada, between 2017 and 2019. Progress curves developed to document the temporal occurrence patterns of each species/lines indicate differences between taxa, with the N-line (BOLD:AAA3453) of D. platura appearing approximately 17 d before D. florilega (BOLD:ACR4394) and the H-line (BOLD:AAG2511) of D. platura.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".