Does Nitrogen Influence Host Choice by a Biological Control Insect
Bibliographic record
Abstract
Previous studies have demonstrated the importance of nitrogen as a component of host plant quality for phytophagous insects, with some insects preferring and performing better on hosts of higher nitrogen content. Although some researchers have investigated the role of nitrogen in host species choice by insect pests, there has been little exploration of how nitrogen may influence host choice patterns, and thus risk assessment, for insects used in weed biological control. The root weevil, Mogulones crucifer Pallas (Coleoptera: Curculionidae), was first released in Canada in 1997 against the rangeland weed, houndstongue (Cynoglossum officinale L.) (Boraginaceae). Both pre and post-release investigations have documented non-target attack on closely-related Boraginaceae species, albeit at a lower level than on houndstongue. Field and laboratory studies also have shown how fertilization of houndstongue with nitrogen can increase M. crucifer population size and weevil feeding and oviposition. As a next investigative step, laboratory studies were conducted using houndstongue and the native North American borage species, Hackelia floribunda (Lehm.) I.M.Johnst., to determine how the addition of nitrogen may alter non-target choice by M. crucifer. Two single-choice experiments (adult feeding and oviposition) were conducted using greenhouse grown houndstongue and non-target plants of either low or high nitrogen content. Leaves from individual plants were paired in small containers so that all possible combinations of plant species and nitrogen level were replicated for each experiment. Laboratory-reared female weevils at their ovipositional peak were added to each container and left for 24 hours to feed (1 female) or 48 hours to oviposit (2 females), before data collection. The results showed no effects of either species or nitrogen level on the amount of feeding by weevils. Although there was some oviposition preference shown for high nitrogen houndstongue, overall, the preference for houndstongue was greater than for the non-target species regardless of nitrogen level.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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 teacher head, 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".