Cooperative Behaviors in Group-Living Spider Mites

Abstract

Cooperative behaviors are evolutionary stable if the direct and/or indirect fitness benefits exceed the costs of helping. Here we discuss cooperation and behaviors akin to cooperation in subsocial group-living species of two genera of herbivorous spider mites (Tetranychidae), i.e., the largely polyphagous Tetranychus spp. and the nest-building Stigmaeopsis spp., which are specialized on grasses, such as bamboo. These spider mites are distributed in patches on various spatial scales, that is, within and among leaves of individual host plants and among individual hosts of single or multiple plant species. Group-living of spider mites is brought about by plant-colonizing foundresses ovipositing at local feeding sites and natal site fidelity, and by multiple individuals aggregating in the same site in response to direct and/or indirect cues, many of which are associated with webbing. In the case of the former, emerging patches are often composed of genetically closely related individuals, while in the case of the latter, local patches may consist of kin of various degrees and/or non-kin and even heterospecific spider mites. We describe and discuss ultimate and proximate aspects of cooperation by spider mites in host plant colonization and exploitation, dispersal, anti-predator behavior, and nesting-associated behaviors and conclude with theoretical and practical considerations of future research on cooperation in these highly rewarding model animals.

Reproductive plasticity in response to the changing cluster size during the breeding period: a case study in a spider mite

“…1 a). It is well known that spider mites collectively spin common silk webs, which help disperse and protect them from predation and environmental hazards (Le Goff et al 2010 ; Yano 2012 ; Schausberger et al 2021 ). Nevertheless, silk is composed mainly of proteins, and thus its production costs energy and nutrient reserved (Hazan et al 1975 ; Oku et al 2009 ).…”

“…In many empirical studies, researchers usually compare the effect of cluster size on fitness by maintaining individuals in consistently small or large clusters during the entire reproductive period (Avileś and Tufinõ 1998 ; Bilde et al 2007 ; Le Goff et al 2010 ; Li and Zhang 2021 ). However, cluster size often changes while individuals are reproducing due to frequent deaths, births, aggregation (immigration) and dispersal (emigration) (Roeder 1992 ; Roff 1992 ; Stearns 1992 ; Price and Hunter 1995 ; Bowman et al 2002 ; Schausberger et al 2021 ). As a result, animals must have developed reproductive plasticity to adapt to dynamic social environment to maximize the fitness of their offspring and their own (Ross et al 2013 ; Radwan et al 2014 ; De Roissart 2016 ; Weerawansha et al 2020 , 2022a , b ; Tinsley Johnson et al 2021 ).…”

“…Spider mites (Acari: Tetranychidae), such as invasive pests Tetranychus ludeni Zacher and Tetranychus urticae Koch, have been used as model species to examine changes of reproductive strategies mediated by social environment (Le Goff et al 2010 ; Macke et al 2012a ; Weerawansha et al 2020 , 2022a , b , c , d ). They live in patchy clusters of varying size and density and produce silk webs for dispersal and protection against predation and environmental hazards (Le Goff et al 2010 ; Yano 2012 ; Schausberger et al 2021 ). Furthermore, cluster-living females elevate egg production compared to solitary ones (Le Goff et al 2010 ; Weerawansha et al 2022a ).…”

“…Furthermore, cluster-living females elevate egg production compared to solitary ones (Le Goff et al 2010 ; Weerawansha et al 2022a ). However, when the cluster size becomes too large (overcrowding), the costs of competition among individuals outweigh the benefits of aggregation and females may leave the oviposition site in search of favourable habitats (Azandémè-Hounmalon et al 2014 ; Li and Zhang 2021 ; Schausberger et al 2021 ; Zhou et al 2021 ), reducing the local cluster size.…”

Restricted hybridisation in the secondary contact zone of closely related haplodiploid social spider mites

“…The mites construct woven nests on the undersurface of the host plant leaves and live in groups within the nests. They are called social spider mites because there are two to three generations of overlap among nest members, and they show cooperative nest building, nest sanitation, and brood care (Saito, 2009;Schausberger et al, 2021). Woven nests are protective against their natural enemies (predatory mites, predatory gall midges, ants, etc.…”