Effects of Gall Induction by Epiblema Strenuana on Gas Exchange, Nutrients, and Energetics in Parthenium Hysterophorus

Abstract

Abstract. Gall induction by arthropods results in a range of morphological and physiological changes in their host plants. We examined changes in gas exchange, nutrients, and energetics related to the presence of stem galls on Parthenium hysterophorus L. (Asteraceae) induced by the moth, Epiblema strenuana Walker (Lepidoptera: Tortricidae). We compared the effects of galls on P. hysterophorus in the rosette (young), pre-flowering (mature), and flowering (old) stages. Gall induction reduced the leaf-water potential, especially in flowering stage plants. In young and mature stage plants, galling reduced photosynthetic rates considerably. Gall induction reduced the transpiration rate mostly in mature plants, and this also diminished stomatal conductance. Energy levels in most galls and in shoot tissue immediately below the galls were significantly higher than the energy levels in stem tissue immediately above the galls, indicating that the gall acts as a mobilizing sink for the moth. Galling had significant effects on concentrations of minerals such as boron, chloride, magnesium, and zinc. In galled plants, reduced leaf-water potential and reduced rates of photosynthesis, transpiration, and stomatal conductance may have altered mineral element levels. These observed effects demonstrate that E. strenuana has the potential to regulate P. hysterophorus.

The imbalance of redox homeostasis in arthropod-induced plant galls: Mechanisms of stress generation and dissipation

“…Leaf tissues, which are primarily adapted for photosynthesis and respiration, can produce completely new structural and functional designs as manifested in a variety of gall morphotypes. These tissues, when altered into galls, show rates of photosynthesis that indicate a positive, negative or neutral influence of the galling herbivores on their host tissues [20,30,38,58,78]. Increased photosynthesis in galls, although rarely observed, was demonstrated in a gall induced by the cynipid Antitrophus silphii on Silphium integrifolium (Asteraceae), and was related to increased water potential in the xylem as well as stomatal conductance [30].…”

A gall-inducing arthropod drives declines in canopy tree photosynthesis

“…The initiation and maintenance of galls on plant organs (i.e., leaves, stems, fruits, and buds) have been shown to alter host traits, such as plant architecture (Larson and Whitham 1997), shoot growth (Vuorisalo et al 1990), and nutrient allocation (Mccrea et al 1985), in addition to impacting whole-plant growth and survival (Hakkarainen et al 2005). Similarly, gall formation has been found to signiWcantly modify foliar gas-exchange processes (i.e., photosynthesis, stomatal water conductance, and water use eYciency), eliciting plant responses ranging from compensatory increases (Fay et al 1993;Dorchin et al 2006) to decreases (Larson 1998;Florentine et al 2005). Thus, the limited information available suggests that the impacts of gall formation on gas-exchange processes are variable and likely determined by the type of gall inducer attacking the host plant (Welter 1989).…”

A new eriophyoid mite species (Acari: Eriophyidae) infesting <i>Haloxylon ammodendron</i> and <i>H. persicum</i> (Chenopodiaceae) in Xinjiang Uigur Autonomous Region, northwest China

“…The galls are beneficial to the survival of the gallinducer. Gall-inducing arthropods spend most of their lives inside the gall, and as a result, it has evolved highly specialized nutritional dependencies on their host plants (Florentine et al 2005). Insects and mites seem to control gall development by modifying the developmental pathways of plant so as to create a protected and favorable environment in which to live (Wool et al 1999;Haiden et al 2012).…”