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Title: Climate‐related geographical variation in performance traits across the invasion front of a widespread non‐native insect
Abstract Aim

Invasive species are ideal systems for testing geographical differences in performance traits and measuring evolutionary responses as a species spreads across divergent climates and habitats. The European gypsy moth,Lymantria dispar disparL. (Lepidoptera: Erebidae), is a generalist forest defoliator introduced to Medford, Massachusetts, USA in 1869. The invasion front extends from Minnesota to North Carolina and the ability of this species to adapt to local climate may contribute to its continuing spread. We evaluated the performance of populations along the climatic gradient of the invasion front to test for a relationship between climate and ecologically important performance traits.

Location

Eastern United States of America

Taxon

Lymantria dispar disparL. (Lepidoptera: Erebidae)

Methods

Insects from 14 populations across the US invasion front and interior of the invasive range were reared from hatch to adult emergence in six constant temperature treatments. The responses of survival, pupal mass and larval development time were analysed as a function of source climate (annual mean normal temperature), rearing temperature and their interaction using multiple polynomial regression.

Results

With the exception of female development time, there were no significant interactions between source climate and rearing temperature, indicating little divergence in the shape of thermal reaction norms among populations. Source population and rearing temperature were significant predictors of survival and pupal mass. Independent of rearing temperature, populations from warmer climates had lower survival than those from colder climates, but attained larger body size despite similar development times. Larval development time was dependent on rearing temperature, but there were not consistent relationships with source climate.

Main Conclusions

Thermal adaptation can be an important factor shaping the spread of invasive species, particularly in the context of climate change. Our results suggest thatL. d. disparis highly plastic, but has undergone climate‐related adaptation in thermal performance and life‐history traits as it spread across North America.

 
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Award ID(s):
1702701
NSF-PAR ID:
10453494
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Journal of Biogeography
Volume:
48
Issue:
2
ISSN:
0305-0270
Page Range / eLocation ID:
p. 405-414
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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