Stellate hairs on leaves of a deciduous shrub Viburnum erosum var. punctatum (Adoxaceae) effectively protect Brevipalpus obovatus (Acari: Tenuipalpidae) eggs from the predator Phytoseius nipponicus (Acari: Phytoseiidae)

Abstract

The eggs of the herbivorous false spider mite Brevipalpus obovatus Donnadieu have a longer incubation period than those of spider mites and are not protected by webs. Brevipalpus obovatus often lays its eggs in the gaps among the hairs on host leaves. We examined the effects of stellate hairs of Viburnum erosum var. punctatum (VEP) leaves on the survival of B. obovatus eggs. Adult B. obovatus and Phytoseius nipponicus Ehara, a generalist predator, were introduced to VEP leaf disks; each B. obovatus egg was inspected daily until hatching. More eggs (63 vs. 42 %) survived on the abaxial surfaces of VEP leaves, where the stellate hairs are more complicated, than on the adaxial surfaces. Predation hazard decreased rapidly with increasing egg age and a substantial portion of the eggs hatched. Phytoseius nipponicus preyed on eggs regardless of egg age when mixed-age eggs were provided. Manipulative experiments with bent stellate hairs showed that the normal hairs reduced the predation risk of B. obovatus eggs by P. nipponicus. Therefore, the predation hazard was considered to decrease since the stellate hairs hindered the search for B. obovatus eggs by the phytoseiid mite.

Genetic and environmental regulation of plant architectural traits and opportunities for pest control in raspberry

“…It has been shown in Viburnum erosum var. punctatum that leaf trichomes protect the eggs of Brevipalpus obovatus from predation by Phytoseius nipponicus Ehara, a generalist predator (Sudo & Osakabe, ). Protection of herbivores by leaf trichomes has been demonstrated in other studies (Eisner et al ., ; Andres & Connor, ), although leaf trichomes can also make it more difficult for herbivores to access leaf tissue (Hanley et al ., ).…”

Distribution and oviposition site selection by predatory mites in the presence of intraguild predators

“…In classic predator-prey systems, it is known that prey select oviposition sites that function as refuges from predators (Horita et al 2004;Bond et al 2005;Lemos et al 2010;Sudo and Osakabe 2013). This oviposition site selection may promote coexistence of predators and prey (Sih 1987;Krivan 1998;Lynch et al 1998).…”

Biological impact of ultraviolet-B radiation on spider mites and its application in integrated pest management

“…The herbivorous false spider mite, Brevipalpus obovatus Donnadieu (Acari: Tenuipalpidae), is another occupier of upper leaf surface (Sudo and Osakabe 2011), and it shows greater UV-B resistance than P. citri (Sudo and Osakabe 2015). Sudo and Osakabe (2013) suggested that B. obovatus has a reduced risk of egg predation by phytoseiid mites such as Phytoseius nipponicus Ehara (Acari: Phytoseiidae), present on the lower leaf surfaces of Viburnum erosum Thunb. var.…”

“…et Sav. (Adoxaceae), by ovipositing on the upper leaf surfaces (Sudo and Osakabe 2013). However, it is difficult for B. obovatus eggs to survive on upper leaf surfaces in summer due to strong detrimental effects of both UV-B radiation and radiant heat from the sun, limiting the field occurrence of this mite to autumn (Sudo and Osakabe 2015).…”

“…Plant-dwelling mites frequently reside on the lower leaf surfaces of their host plants (Sudo and Osakabe 2011). In addition to topographic differences between adaxial (upper) and abaxial (lower) leaf surfaces (Chien and Sussex 1996;Price 1980;Sakai et al 2012a;Sudo and Osakabe 2013), the preference for lower leaf surfaces by tiny mites (Jeppson 1975;Kiritani 2012Kiritani , 2013 has been attributed to avoidance of harsh environments on upper leaf surfaces such as radiant heat (Lu et al 2014;Perring et al 1984), desiccation (Ferro and Chapman 1979;McEnroe 1961) and rain (Boyne and Hain 1983;Ho 2000;Osakabe 1965;Rêgo et al 2013).…”