Environmental Entomology (1990) 19, 937-942

Salma N. Talhouk, David G. Nielsen and Michael E. Montgomery (1990)
Water deficit, defoliation, and birch clones: short-term effect on gypsy moth (Lepidoptera: Lymantriidae) performance
Environmental Entomology 19 (4), 937-942
Abstract: Two clones of paper birch from different geographic origins were used to determine short-term effects of water deficit and partial defoliation on photosynthetic rate, stomatal resistance, and sucrose levels in leaves, and on the performance of fourth-instar gypsy moth, Lymantria dispar (L.). Water stress, sufficient to cause wilting at midday, reduced photosynthesis by 90% and increased stomatal resistance 10 times. Sucrose levels in leaves were initially the same in stressed and unstressed plants, but after 10 d of stress sucrose was higher in leaves of water-stressed plants of one clone ('S5' birch), but not in the other (WM-148' birch). Fourth instars, placed on 'S5' plants when midday wilting first occurred, produced more frass and had higher relative growth rates than larvae on well-watered plants. These changes were not observed for a second cohort of larvae placed on the same clone about 10 d after wilting first occurred. On clone 'WM-148,' which was more suitable than the 'S5' clone, larval performance was not different on water-stressed plants versus well-watered plants, whether they were introduced immediately or 10 d after wilting first occurred. Relative growth rate was lower for larvae feeding on partially defoliated plants versus undefoliated plants of both clones.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Michael E. Montgomery

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Lymantria dispar	Birch (Betula)