The ecology and the biological control of the annual bluegrass weevil, Listronotus maculicollis Kirby (Coleoptera: curculionidae) using entomopathogenic nematodes (rhabditida: steinernematidae and heterorhabditidae)
Bibliographic record
Abstract
The annual bluegrass weevil, Listronotus maculicollis Kirby, is a highly destructive insect pest of fine turfgrass in the northeastern United States and eastern Canadian provinces. I examined the spatial ecology of L. maculicollis and assessed the virulence of endemic and released entomopathogenic nematodes to weevil stages to develop ecologically based control programs. Endemic populations of Steinernema carpocapsae Weiser and Heterorhabditis bacteriophora Poinar infected a range of weevil instars and caused moderate generational mortality. The variability in seasonal abundance of endemic nematode populations and the variability in weevil generational mortality suggests an inability for reliable pest population regulation. Laboratory bioassays demonstrated that L. maculicollis fourth- and fifth-instar larvae were moderately to highly susceptible to nematode infection. Several species of nematodes significantly reduced densities of both instars, although a decrease in susceptibility to nematodes was observed as the insect aged. No difference was observed between the virulence of endemic and commercial nematode strains to any L. maculicollis stage tested. Field trials conducted over a three year period demonstrated great variability in the ability of commercial and endemic nematodes applied at standard field concentrations to reduce L. maculicollis densities below damage thresholds. Many factors, including nematode concentration, weevil spatial distribution and density, and timing of application are believed to have contributed to the variability in control. The spatio-temporal distribution of emerging overwintering adult populations, first generation larvae and the distribution of host plants were examined to identify the spatial structure of populations, better target curative controls and develop monitoring programs. Significant aggregations of cumulative adult captures, larvae and their preferred hosts (Poa annua L.) were found on fairway edges when the entire width of fairways was sampled. Adult distribution rarely coincided with the following week's spatial pattern, suggesting that adults actively disperse across fairways throughout the oviposition period. Spatial association was detected between adults and larvae, but rarely between either stage and P. annua. The findings challenge assumptions of L. maculicollis host preference, but suggest a potential for targeting controls. The data were used to develop sequential sampling programs to rapidly assess adult densities and estimate the threat of larval damage.
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 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) | 0.000 | 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 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".