DOI: 10.5061/dryad.kd51c5bhh
title: Climate change is leading to an ecological trap in a migratory insect

description: Many insect migrants rely on favorable seasonal winds to carry out
 long-range latitudinal migrations. In East China, the annual advance and
 retreat of the East Asian summer monsoon produces ideal conditions for
 seasonal range expansion and contraction of many migratory crop pests.
 However, climate-induced changes in the strength, timing, and location of
 the monsoon are impacting wind systems which may, in turn, affect
 migration patterns. We investigated these questions in the rice leafroller
 (RLR) moth, a severe pest of rice that annually invades the Lower Yangtze
 River Valley (LYRV) of China from winter-breeding areas further south.
 Using a 24-y dataset of RLR population dynamics from 31 monitoring
 stations across Southeast China, we investigated the impact of changes in
 monsoon wind regimes on fall migration patterns of the pest. Historically,
 RLR emigrated from the LYRV to South China on the favorably directed winds
 produced by the retreat of the monsoon at the end of the outbreak season
 (from mid-August onward). We show that in the recent 12-y period,
 prevailing late-season winds remain northward for longer than previously,
 preventing locally produced moths from emigrating southward. Additionally,
 winds now facilitate mass late-season immigrations into the LYRV, creating
 an ecological trap, as immigrants do not have time to produce another
 generation. As a consequence of the changing wind patterns, pest pressure
 is declining, and climate-induced changes to the East Asian summer monsoon
 result in seasonal migration becoming a riskier strategy. Such changes in
 insect migration patterns have severe implications for the population
 dynamics of windborne migrants, ecosystem functioning, and pest management
 strategies.
description: Five-day RLR number in field and daily catch data from 11
 stations in the Lower Yangtze River Valley (LYRV) obtained from the
 National Agro-Tech Extension and Service Centre (NATESC), which has been
 continuously collecting data since 2000. Field surveys involved plant
 protection station staff walking a standardized transect through a rice
 paddy every day during the season when moths are present in the area, and
 counting the number of adult RLR flushed from the crop. Nightly abundance
 of adult moths in the vicinity of the rice paddies where field surveys
 were conducted was monitored by counting the number of moths caught every
 night in standardized 20- W “black- light” (UV) traps.
description: # Title of Dataset: Climate change is leading to an ecological trap in a
 migratory insect --- 5-day RLR number in field and daily catch data from
 11 stations in the Lower Yangtze River Valley (LYRV) obtained from the
 National Agro-Tech Extension and Service Centre (NATESC), which has been
 continuously collecting data since 2000. ## Description of the Data and
 file structure The dataset contains two tables/sheets: 5-day RLR number in
 field survey, Daily RLR catch in light trap The table/sheet named
 '**field_survey**' includes six columns: Year, Month, Period,
 Longitude, Latitude, Number * Year: 2000-2023 year * Month: Mar=3,
 April=4, May=5, June=6, July=7, Aug=8, Sept=9, Oct=10 * Period: 5-day
 period; 1-5 means the 1st to 5th day of the month, 6-10 means the 6th to
 10th day of the month, and so on. * Longitude: The longitude degree of the
 location of site (numerical degree) * Latitude: The latitude degree of the
 location of site (numerical degree) * Number: Numerical No. of
 individuals. Total number of RLR moth per hectare of rice paddy across the
 occurrence season. '-999' means a missing value. The table/sheet
 named '**light_trap**' includes four columns: Date, Longitude,
 Latitude, Number * Date: YYYY-MM-DD * Longitude: The longitude degree of
 the location of site (numerical degree) * Latitude: The latitude degree of
 the location of site (numerical degree) * Number: Numerical No. of
 individuals. Total number of RLR moth caught by a standardized 20-W
 “black-light” (UV) trap each night. '-999' means a missing
 value.