Influence of leaf trichomes on predatory mite (Typhlodromus pyri) abundance in grape varieties

Abstract

Non-glandular leaf trichomes positively inXuence the abundance of many phytoseiid mites. We characterized the inXuence of grape leaf trichomes (domatia, hairs, and bristles) on Typhlodromus pyri Scheuten abundance over two years in a common garden planting of many grape varieties and 2 years of sampling in a commercial vineyard. In general, a lack of trichomes was associated with much lower predator numbers and in the case of Dechaunac, a cultivar with almost no trichomes, very few T. pyri were found. Phytoseiid abundance was best predicted by a model where domatia and hair had an additive eVect (r 2 = 0.815). Over two years of sampling at a commercial vineyard there were T. pyri present on all of the 5 cultivars except Dechaunac. At the same time, European red mite prey were present on Dechaunac alone. These results suggest that on grape cultivars lacking leaf trichomes, T. pyri likely will not attain suYcient densities to provide biological control of European red mite, despite presence of the mite food source. The relationship between leaf trichomes and phytoseiid abundance that is observed at the scale of single vines in a garden planting appears to also be manifest at the scale of a commercial vineyard. Because persistence of predatory mites in or nearby the habitats of prey mites is important for eVective mite biological control, leaf trichomes, through their inXuence on phytoseiid persistence, may be critical for successful mite biological control in some systems.

Dinâmica populacional de Calepitrimerus vitis (Nalepa) (Acari: eriophyidae) em cultivares de videira na região da campanha do Rio Grande do Sul

“…Segundo Duso e Vettorazzo (1999), os fitoseídeos Kampimodromus aberrans (Oudemans) e Typhlodromus pyri Scheuten estão mais adaptados às cultivares pilosas, e Amblyseius andersoni (Chant), às cultivares glabras. Nesse sentido, estudos realizados com 12 cultivares de videira, nos Estados Unidos da América, identificaram uma correlação forte entre a sobrevivência no vinhedo de T. pyri e a densidade de tricomas não glandulares nas folhas (LOUGHNER et al, 2008).…”

<p class="Body"><strong>Re-description of <em>Neoseiulus</em> <em>bicaudus</em> (Acari: Phytoseiidae) newly recorded from Xinjiang, China</strong></p>

“…The number of trichomes have no obvious impacts on the total fecundity. However, Loughner (2008) reported that a lack of trichomes was associated with much lower predator numbers. The fecundity is an important factor that effects on the number of arthropod (Loughner et al 2008).…”

Nicotiana tabacumTTG1 contributes to ParA1-induced signalling and cell death in leaf trichomes

“…Trichomes on the surfaces of aerial parts of plants are distributed like biological antenna exposed to a variety of environmental cues (Roy et al, 1999;Wagner, 1991) and serve as the first procession for plants to encounter multiple extrinsic challenges (Amme et al, 2005;Loughner et al, 2008). Growing at the most external parts of plants, leaf trichomes are assumed to function as a channel to connect the extrinsic signals with intrinsic plant signalling pathways (Amme et al, 2005;Kanzaki et al, 2008;Roy et al, 1999;Traw and Bergelson, 2003).…”

“…In many cases, trichomes interfere with the feeding of herbivores (Esau, 1965) and constitute physical defensive structures, which sometimes simply have the potential to impede infestation of insect pests (Ambrósio et al, 2008). Alternatively, plant protection can be provided by natural enemies of insects that impose selection for increased trichome density (Loughner et al, 2008). Evidence also shows the influence of leaf trichomes on foliar fungal infection; to prevent these infections, trichomes are particularly important because they secrete compounds that have antimicrobial activities and contribute to plant defence against pathogens (Amme et al, 2005;Calo et al, 2006;Skaltsa et al, 1994).…”