DOI: 10.5061/dryad.4j0zpc8rn
title: Data from: A conceptual model for the eiapause intensity curve and termination in overwintering Japanese Pine Sawyer larvae, <em>Monochamus alternatus</em> (Coleoptera: Cerambycidae)

description: 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.
description: # Data from: A conceptual model for the eiapause intensity curve and
 termination in overwintering Japanese Pine Sawyer larvae, *Monochamus
 alternatus* (Coleoptera: Cerambycidae) Dataset DOI:
 [10.5061/dryad.4j0zpc8rn](https://doi.org/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