Reproductive Biology of Ceutorhynchus obstrictus (Coleoptera: Curculionidae) on Wild and Cultivated Brassicaceae in Southern Alberta
Bibliographic record
Abstract
Mated and gravid status were assessed for early-season populations of Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae) on wild and cultivated Brassicaceae in southern Alberta, Canada. Mated female C. obstrictus were found in the first samples examined (22 May 2001). At least 84% of C. obstrictus dispersing to wild host sites up to 23 May 2001 (captured using yellow pan traps) were males. Females of C. obstrictus with at least one egg in the lateral oviducts were first encountered on 6, 8 and 18 June 2001 on Descurainia sophia (L.) Webb, Sinapis arvensis L., and Cardaria spp., (Brassicaceae), respectively. Females on S. arvensis, a true host with pods that can sustain larvae, had more robust ovary development than females on Cardaria spp. and D. sophia, food hosts with pods that cannot sustain larvae. The most fecund sample (n = 30) from S. arvensis was collected on 24 June 2001 when 80% of females had a mean of 7.2 ± 2.7 (±SD) eggs in the lateral oviducts. The most fecund full samples (n = 30) from Cardaria spp. and D. sophia had 6.7% and 40.0%, respectively, of females with at least one egg in the lateral oviducts, and an overall maximum of four eggs in the lateral oviducts per female. There is no apparent reproductive advantage to C. obstrictus in developing eggs on early-season food hosts, although food hosts likely play an important role in sustaining C. obstrictus until true hosts are encountered. Although gravid status was high in females on S. arvensis, this host supported relatively few larvae. The highest infestation level of C. obstrictus per sample of S. arvensis pods in 2001 was 13.5% (n = 891 pods) based on the presence of eggs, larvae, and exit holes. A sample of volunteer Brassica napus L. (Brassicaceae) pods (n = 100) had a 77% infestation level. The apparent discrepancy between the relatively robust gravid status of C. obstrictus on S. arvensis, and low pod infestation, was explained as a combination of factors that likely include an inherent unsuitability of wild S. arvensis pods for C. obstrictus. However, given the wide distribution of S. arvensis in southern Alberta, this wild true host would likely maintain low populations of C. obstrictus in the absence of volunteer and spring-seeded cultivated hosts.
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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 | 0.001 |
| Science and technology studies | 0.001 | 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".