Potential lethal and non-lethal effects of predators on dispersal of spider mites

Abstract

Predators can affect prey dispersal lethally by direct consumption or non-lethally by making prey hesitate to disperse. These lethal and non-lethal effects are detectable only in systems where prey can disperse between multiple patches. However, most studies have drawn their conclusions concerning the ability of predatory mites to suppress spider mites based on observations of their interactions on a single patch or on heavily infested host plants where spider mites could hardly disperse toward intact patches. In these systems, specialist predatory mites that penetrate protective webs produced by spider mites quickly suppress the spider mites, whereas generalist predators that cannot penetrate the webs were ineffective. By using a connected patch system, we revealed that a generalist ant, Pristomyrmex punctatus Mayr (Hymenoptera: Formicidae), effectively prevented dispersal of spider mites, Tetranychus kanzawai Kishida (Acari: Tetranychidae), by directly consuming dispersing individuals. We also revealed that a generalist predatory mite, Euseius sojaensis Ehara (Acari: Phytoseiidae), prevented between-patch dispersal of T. kanzawai by making them hesitate to disperse. In contrast, a specialist phytoseiid predatory mite, Neoseiulus womersleyi Schicha, allowed spider mites to escape an initial patch, increasing the number of colonized patches within the system. Our results suggest that ants and generalist predatory mites can effectively suppress Tetranychus species under some conditions, and should receive more attention as agents for conservation biological control in agroecosystems.

The effect of predation risk on spermatophore deposition rate of the eriophyoid mite, Aculops allotrichus

“…To assess the risk of predation, a prey can use cues produced by a predator (e.g., kairomones emitted from the predator’s body, faeces, urine or other exudates) or indirect cues of predation, e.g., alarm pheromones produced by conspecifics or cues from dead conspecifics (Thorson et al 1998 ; Grostal and Dicke 2000 ). Recent findings reveal that phytophagous mites, such as spider mites, can also respond to predation risk by avoiding leaf patches with cues of phytoseiid mites or other predatory arthropods and/or injured conspecifics on them (Kriesch and Dicke 1997 ; Grostal and Dicke 1999 , 2000 ; Magalhães et al 2002 ; Oku et al 2003 ; Choh and Takabayashi 2007 ; Bowler et al 2013 ; Otsuki and Yano 2014 ). Moreover, they also reduce oviposition when under elevated predation risk (Grostal and Dicke 1999 , 2000 ; Oku et al 2004 ; Škaloudová et al 2007 ; Fernández-Ferrari and Schausberger 2013 ; Hackl and Schausberger 2014 ).…”

Bugs scaring bugs: enemy‐risk effects in biological control systems

“…Behavioural shifts are a commonly studied trait responses in arthropods, and are generally the most rapid and reversible. Examples include changes in time spent feeding (Thaler and Griffin, 2008;Jandricic et al, 2016;Ingerslew and Finke, 2017), food source (Schmitz et al, 1997), microhabitat and refuge use (Lucas et al, 2000;Lawson-Balagbo et al, 2007;Penfold et al, 2017), oviposition rate (Deas and Hunter, 2013;Hermann and Thaler, 2018), oviposition site selection (Angelon and Petranka, 2002;Vonesh and Blaustein, 2010;Silberbush and Blaustein, 2011), short-distance escape (Tamaki et al, 1970;Nelson, 2007;Fill et al, 2012) and dispersal (H€ oller et al, 1994;Henry et al, 2010;Welch and Harwood, 2014;Otsuki and Yano, 2014b).…”

Bugs scaring bugs: enemy-risk effects in biological control systems

“…Behavioral shifts are a commonly studied trait responses in arthropods, and are generally the most rapid and reversible. Examples include changes in time spent feeding (Thaler & Griffin 2008;Jandricic et al 2016;Ingerslew & Finke 2017), food source (Schmitz et al 1997), microhabitat and refuge use (Lucas et al 2000;Lawson-Balagbo et al 2007;Penfold et al 2017), oviposition rate (Deas & Hunter 2013;Hermann & Thaler 2018), oviposition site selection (Angelon & Petranka 2002;Vonesh & Blaustein 2010;Silberbush & Blaustein 2011), short-distance escape (Tamaki et al 1970;Nelson 2007;Fill et al 2012), and dispersal (Holler et al 1994;Henry et al 2010;Otsuki & Yano 2014b;Welch & Harwood 2014).…”