Characterization of nucleopolyhedroviruses infecting western (Malacosoma californicum pluviale) and forest tent caterpillars (Malacosoma disstria) in British Columbia, and detection of sublethal infection in field populations of forest tent caterpillars
Bibliographic record
Abstract
Viral diseases are an important feature of fluctuating lepidopteran populations. Epizootics of baculovirus disease can kill large numbers of hosts, making them attractive agents or biological control. The drive to improve virus efficacy by genetic manipulation has focused attention on the behaviour of baculoviruses in nature. I examined the genetic diversity present in nucleopolyherovirus (NPV) populations infecting tent caterpillars in British Columbia. Natural baculovirus isolates are genetically diverse in many different lepidopteran systems. I used REN analysis to survey genetic diversity in six different NPV populations infecting the western tent caterpillar, Malacosoma californicum pluviale (Dyar). In total, 14 genetic variants were found among the six populations sampled. Genetic variation was structured at the population level. Bioassays detected subtle differences in pathogenecity associated with different NPV populations, suggesting that local genetic variation in NPV could influence local host dynamics. The use of baculoviruses as biopesticides has emphasized a need to determine host range for a number of different viruses. I characterized the NPVs infecting two closely related host species, the western tent caterpillar, Malacosoma californicum pluviale (Dyar), and the forest tent caterpillar, Malacosoma disstria (Hiibner), and determined the cross infective potential of each virus. M.c. pluviale NPV (McplNPV) and M.-disstria NPV (MadiNPV) were genetically distinct. Cross infection bioassays demonstrated that 3rd instar M.c. pluviale larvae were not susceptible MadiNPV. In the reciprocal cross infection, only a small proportion of M. disstria larvae was susceptible to McplNPV. The majority of mortalities were the result of an unexpected MadiNPV infection. PCR failed to detect MadiNPV contamination in the McplNPV stock. Laboratory contamination and contamination of egg mass surfaces were unlikely. I suggest the virus was present as either a latent or sublethal infection that was vertically transmitted from females to larvae within the eggs themselves. These findings suggest that NPV may influence host dynamics. First, genetic variability may be associated with life history traits important for virus survival and may therefore influence local host dynamics. Second, the detection of a latent or sublethal infections provides a mechanism for both enhancing virus dispersal and maintaining virus during low host densities.
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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 | 0.000 |
| 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".