The effect of chrysanthemum leaf trichome density and prey spatial distribution on predation of Tetranychus urticae (Acari: Tetranychidae) by Phytoseiulus persimilis (Acari: Phytoseiidae)

Abstract

The effect of plant architecture, in terms of leaf hairiness, and prey spatial arrangement, on predation rate of eggs of the spider mite, Tetranychus urticae Koch, by the predatory mite Phytoseiulus persimilis Athias-Henriot was examined on cut stems of chrysanthemums. Three levels of leaf hairiness (trichome density) were obtained using two different chrysanthemum cultivars and two ages within one of the cultivars. The number of prey consumed by P. persimilis was inversely related to trichome density. At low prey densities (less than ten eggs per stem), prey consumption did not differ in a biologically meaningful way between treatments. The effect of prey spatial arrangement on the predation rate of P. persimilis was also examined. Predation rates were higher in prey patches on leaves adjacent to the release point of P. persimilis, but significantly greater numbers of prey were consumed in higher density prey patches compared to low density patches. The predators exhibited non-random searching behaviour, spending more time on leaves closest to the release point. The implications of these findings for biological control and predator-prey dynamics are discussed.

Arabidopsis-Insect Interactions

“…As structural features, they may hinder or help landing, impede movement, alter the microclimate, reduce predation rates when they hamper carnivores and can be climbed by small herbivores to avoid detection by predators. On the other hand, trichomes may increase predation rates as some predators lay their eggs in trichome dense areas to avoid intra-guild predation and can use pollen trapped by trichomes as alternative food source (Southwood, 1986;Krips et al, 1999;Roda et al, 2000;Michalska, 2003;Roda et al, 2003;Stavrinides and Skirvin, 2003). In the case of glandular trichomes, they are also part of chemical defenses against herbivores (e.g Chatzivasileiadis and Sabelis, 1997;Maluf et al, 2001), but as trichomes in Arabidopsis are non-glandular, single cells I will not discuss this further.…”

Abundância e sazonalidade do ácaro-rajado em cultivares de gérbera

“…Outra possibilidade a ser considerada seria a atratividade natural da variedade PS que, ao liberar voláteis para comunicação interespecífica pode se tornar preferencial ao ácaro rajado (PALLINI et al, 2001). Além deste, outros aspectos, como a coloração das flores, forma das folhas, densidade de tricomas, características bioquímicas e grau de resistência à T. urticae também podem ter efeito sobre a abundância dos ácaros em cada cultivar (KIELKIEWICZ & DICKE, 1992, SÜTERLIN & VAN LENEREN, 1997, KRIPS et al, 1999, STAVRINIDES & SKIRVIN, 2003, WATANABE, 2007.…”

Systematic significance and pharmaceutical potentials of trichomes in accessions of Sesamum indicum L. Pedaliaceae

“…The hairs generally are thought to help keep the leaf cool and also prevent rapid wind current from passing close to the surface and thus removing water vapour from transpiring areas thereby reducing the rate of transpiration (Fahn, 1990). The number of trichomes produced and trichome density vary genetically within several species (Dalin et al, 2008); but in most empirical studies, the abundance and effectiveness of natural enemies were found to be negatively correlated with the density of plant trichomes (Lovinger et al, 2000;Fordyce and Agrawal, 2001;Stavrinides and Skirvin, 2003;Mulatu et al, 2006;Olson and Andow, 2006). Thus, Ex-Gombe 3 which recorded high trichome density could be drought-tolerant accession because Abdulraham and Oladele (2004) reported that plants with high trichome density have high capacity to conserve water.…”