Data from: A conceptual model for the eiapause intensity curve and termination in overwintering Japanese Pine Sawyer larvae, Monochamus alternatus (Coleoptera: Cerambycidae)
Data files
Nov 05, 2025 version files 5.79 KB
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Chilling_experiment_data.csv
2.01 KB
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Field-aged_data.csv
891 B
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README.md
2.90 KB
Abstract
The Japanese pine sawyer (Monochamus alternatus Hope; Coleoptera: Cerambycidae) is a primary vector of the pine wood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer), which causes pine wilt disease (PWD). We investigated the progression of larval diapause in M. alternatus, focusing on changes in diapause intensity under controlled chilling at 9 °C and validation with field-aged larvae. Larvae collected in late October did not pupate after 0–10 days of chilling, representing an initial refractory phase in which diapause intensity was maximal. With increasing chilling duration, development time to pupation progressively decreased, reaching a stable baseline after 110 days, which marked diapause termination. Diapause intensity was expressed as the additional time to pupation relative to post-diapause larvae and visualized as a declining curve fitted with an extreme value cumulative function. Following transfer to different incubation temperatures, additional chilling produced disproportionately large reductions at 18 °C compared with warmer conditions, indicating that the residual inhibitory state at transfer strongly influences subsequent development. Field-aged larvae yielded a precise estimate of diapause termination on 15 March, and cumulative chilling within 2–15 °C by this date matched the 110-day benchmark from laboratory experiments. These findings demonstrate that the 2–15 °C range defines the effective chilling window for this species. By integrating laboratory and field evidence, we provide the first complete diapause intensity curve for M. alternatus and establish an empirical basis for predicting spring adult emergence. This framework advances our understanding of diapause ecology and contributes to phenology-based management of pine wilt disease.
Dataset DOI: 10.5061/dryad.4j0zpc8rn
Description of the data and file structure
1. Chilling_experiment_data.csv — Development time data under different chilling durations at 9 °C
Pine logs infested with M. alternatus larvae were collected on October 24, 2016, from felled pine trees in a forest in Jeju City, Korea, where logging was conducted for eradication purposes.
The collected logs were transported to a plastic greenhouse at Jeju National University, where they were split using a hand axe to extract larvae.
The collected diapausing larvae were individually placed in sterilized Petri dishes (diameter: 5 cm; height: 1.5 cm) lined with pine sawdust. These larvae were then maintained in a growth chamber (Model: DS-14MCLP, Dasol Ltd., Korea) at 9 °C in complete darkness.
At 0, 10, 30, 50, 70, 90, 110, and 130 days after the start of chilling treatment, 30 to 36 larvae were randomly selected and transferred to new growth chambers set at 18, 22, and 26 °C (10 to 12 larvae at each temperature). The larvae were monitored daily until pupation.
2. Field-aged_data.csv — Development time data for field-aged larvae
Field-aged diapausing larvae were collected from the remaining pine logs in the field mesh house at four time points: December 27, 2016, January 24, 2017, February 27, 2017, and March 27, 2017.
At each time point, 27-30 larvae were retrieved and subjected to the same growth chamber treatments (18, 22, and 26 °C) as described above. The larvae were checked daily for pupation.
Files and variables
File: Chilling experiment data.csv
Description: Changes in the development time (days) of diapausing M. alternatus larvae to pupation after different chilling periods (9 °C) when subsequently incubated at constant temperatures.
Three data sets were included: development times in days at 18, 22, and 26 °C.
Variables
- Replicate : the number of larvae.
- 0 days CA through 130 days CA : Cold storage (CA) duration at 9 °C in days of 0 days through 130 days, respectively.
File: Field-aged data.csv
Description: The development times in days to pupation of diapausing, field-aged M. alternatus larvae incubated at constant temperatures on different collection dates
Three data sets were included: development times in days at 18, 22, and 26 °C.
Variables
- Replicate : the number of larvae.
- 27-Dec: collected the date of field-aged larvae on 27 December
- 24-Jan: collected the date of field-aged larvae on 24 January
- 27-Feb: collected the date of field-aged larvae on 27 February
- 29-Mar: collected the date of field-aged larvae on 29 March