Body size mediates ground beetle dispersal from non-crop vegetation: Implications for conservation biocontrol
Bibliographic record
Abstract
Intensifying agricultural landscapes by removing non-crop vegetation threatens ecosystem services like pest regulation. Non-crop areas may serve as overwintering habitat for natural enemy arthropods that disperse into and predate on insect pests in the adjacent field. However, managing this service requires greater understanding of the mechanisms driving this dispersal and the subsequent control of pests by arthropod predators. A functional trait framework, i.e., studying the traits of predators that influence their foraging behaviour and dispersal, supports generalization across cropping systems where conditions differ (e.g., which arthropod taxa are present). Predator body size, a trait known to influence both dispersal distance and prey consumption, is a plausible mechanism governing the supply and the effective delivery of pest control. We focused on ground beetles (Coleoptera: Carabidae), common insect predators found globally in agroecosystems. We measured 27,815 beetles collected in 20 crop fields from 180 sampling stations to examine how body size changes with distance from non-crop vegetation. We tested the effect of predator body size on foraging behaviour by exposing 77 Pterostichus melanarius ground beetles to different sizes of the model pest Trichoplusia ni (Lepidoptera: Noctuidae). The smallest six deciles of carabid body size increased in size with distance from non-crop vegetation, demonstrating that more smaller beetles are found closer to the field edge and that body size is a predator trait mediating the distance of dispersal. Larger P. melanarius show a trend towards predating larger prey than smaller prey, though we were unable to reject a null hypothesis of no effect (α=0.05; P=0.08). This affirms that body size is a plausible trait governing the effectiveness of pest control, and that size-based foraging behaviour requires in-field investigation. Our findings reinforce calls for more and better-protected non-crop vegetation areas in agroecosystems intended to control a diverse array of insect pests. Placing non-crop vegetation patches closer to crops (e.g., through restoration or reducing field size) is a critical lever for manipulating the body size distribution of predators in the crop, and subsequently may affect the prey that can be controlled without the use of pesticides. • Ground beetles measured from 20 field sites with 180 sampling stations (N=20 407). • Smaller beetles disperse from the edge less far into the crop than larger beetles. • Marginal areas are important for small beetles. • Proximity to field margins may support in-crop predation of a range of prey sizes.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| 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) | 0.000 | 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".