Testing a new hypothesis: plant vigor and phylloxera distribution on wild grape in Arizona

Abstract

Longer, meaning more vigorous, shoots of a wild grape clone (Vitis arizonica) were more susceptible to attack by second and third generations of leaf-galling grape phylloxera,Daktulopsphaira vitifoliae, as the growing season progressed. Although there was no significant difference in mean shoot length between attacked and unattacked shoots within a clone at the beginning of shoot elongation, attacked shoots were significantly longer than unattacked shoots when elongation had ceased (P<0.01). Also, long attacked shoots had a significantly greater population of phylloxera galls than short attacked shoots (P<0.01) as the season progressed. The phylloxera population on long shoots increased rapidly while the population on short shoots remained the same. Longer shoots also produced significantly more axillary shoots than shorter shoots as the season progressed (P<0.001), and the number of axillary shoots accounted for 66 percent of the variance in number of attacked leaves on a shoot. Experimental evidence showed that there was a significantly greater percentage of available leaves attacked on long shoots than on short shoots (P<0.05) and the leaves on long shoots generally had a greater number of galls per leaf. The relationship between shoot length and probability of attack was also tested by comparing shoots lengths of 10 attacked clones and 10 unattacked clones at a second location. Mean shoot lengths of attacked clones were significantly longer than mean shoot lengths of unattacked clones (P<0.05), and mean shoot lengths of attacked shoots within a clone were significantly longer than unattacked shoots (P<0.001). Longer shoot length accounted for 81 percent of the variance in probability of attack. The reason for this pattern of attack was that long shoots produced newly expanding leaves over a longer time during the growing season and multivoltine phylloxera require undifferentiated tissue to initiate gall formation. Patterns of attack within a shoot were characterized by an uneven distribution of galls among leaves. This was due to development time between generations and the current availability of undifferentiated tissue at times of colonization. This study supports the hypothesis that some herbivore species are favored more by vigorous plants than by stressed plants.

Interactive effects of host resistance and drought stress on the performance of a gall-making aphid living on Norway spruce

“…Gall diameter was correlated to tree growth, in accordance with the modified plant stress hypothesis (Larsson 1989) and the plant vigour hypothesis (Kimberling et al 1990;Price 1991). Although the effect of drought on gall diameter was significant, after 2 years of treatment there was no difference between drought-stressed, susceptible trees and control, resistant trees.…”

Size does matter: variation in herbivory between and within plants and the plant vigor hypothesis

“…2 Diptera galler abundance Cornelissen et al 1997 Bauhinia brevipes Geometridae sp. 1 Lepidoptera chewer abundance Craig et al 1989 Solidago altissima Euura lasiolepis Diptera galler abundance Craig et al 1999 Solidago altissima Eurosta solidaginis Diptera galler abundance Craig et al 2000 Solidago Kimberling et al 1990 Vitis arizonica Daktulospahira vitifoliae Homoptera galler abundance Kimberling and Price 1996 Vitis arizonica Daktulospahira vitifoliae Homoptera galler abundance, survivorship Kozlov 2003 Alnus incana Phyllonorycter strigulatella Lepidoptera miner abundance Krause and Raffa 1996 Larix decidua Pristiphora erichsonii Hymenoptera chewer abundance Krause and Raffa 1996 Larix leptolepis Pristiphora erichsonii Hymenoptera chewer abundance Kuczynski and Skoracka 2005 Salix spp. Aculus tetanothrix Acari galler abundance Leyva et al 2000 Pseudotsuga menziesii Choristoneura occidentalis Lepidoptera chewer abundance Manninen et al 1998 Pinus sylvestris Schizolachnus pineti Homoptera sap sucker abundance Manninen et al 1998 Pinus sylvestris Eulachnus agilis Homoptera sap sucker abundance Manninen et al 1998 Pinus Prada et al 1995 Aspilia foliaceae unidentified Coleoptera flower feeder abundance Prada et al 1995 Aspilia foliaceae unidentified Diptera flower feeder abundance Prezler and Price 1995 Salix lasiolepis Phyllonorycter sp. Lepidoptera miner abundance, survivorship Price et al 1987 Salix cinerea Euura mucronata Hymenoptera galler abundance Price et al 1995 Caesalpina sp.…”

Long term oviposition preference and larval performance of Schizomyia macrocapillata (Diptera: Cecidomyiidae) on larger shoots of its host plant Bauhinia brevipes (Fabaceae)

“…The Plant Vigor Hypothesis (PVH; Price 1991) predicts that insect herbivores will choose preferentially large, more vigorously growing plants or plant modules and that offspring performance will be greater on these more vigorous plants or plant modules. Its predictions have been widely tested in diverse ecosystems around the world, being either fully supported (Price et al 1987a, b;Craig et al 1989;Kimberling et al 1990; Price and Ohgushi 1995;Stein and Price 1995;Woods et al 1996;Carr et al 1998;Inbar et al 2001;de Bruyn et al 2002), partially supported (Cornelissen et al 1997;Prado and Vieira 1999;Cornelissen and Fernandes 2001c;Fritz et al 2000;Ferrier andPrice 2004), or refuted (de Bruyn 1995;Faria and Fernandes 2001;Rehill and Schultz 2001). Faria and Fernandes (2001) argued that the amount of resources has been generally underestimated in large size class shoots.…”