Do plant mites commonly prefer the underside of leaves?

Abstract

The adaxial (upper) and abaxial (lower) surfaces of a plant leaf provide heterogeneous habitats for small arthropods with different environmental conditions, such as light, humidity, and surface morphology. As for plant mites, some agricultural pest species and their natural enemies have been observed to favor the abaxial leaf surface, which is considered an adaptation to avoid rain or solar ultraviolet radiation. However, whether such a preference for the leaf underside is a common behavioral trait in mites on wild vegetation remains unknown. The authors conducted a 2-year survey on the foliar mite assemblage found on Viburnum erosum var. punctatum, a deciduous shrub on which several mite taxa occur throughout the seasons, and 14 sympatric tree or shrub species in secondary broadleaf-forest sites in Kyoto, west-central Japan. We compared adaxial-abaxial surface distributions of mites among mite taxa, seasons, and morphology of host leaves (presence/absence of hairs and domatia). On V. erosum var. punctatum, seven of 11 distinguished mite taxa were significantly distributed in favor of abaxial leaf surfaces and the trend was seasonally stable, except for Eriophyoidea. Mite assemblages on 15 plant species were significantly biased towards the abaxial leaf surfaces, regardless of surface morphology. Our data suggest that many mite taxa commonly prefer to stay on abaxial leaf surfaces in wild vegetation. Oribatida displayed a relatively neutral distribution, and in Tenuipalpidae, the ratio of eggs collected from the adaxial vs. the abaxial side was significantly higher than the ratio of the motile individuals, implying that some mite taxa exploit adaxial leaf surfaces as habitat.

Seasonal changes in the deleterious effects of solar ultraviolet-B radiation on eggs of the twospotted spider mite, Tetranychus urticae (Acari: Tetranychidae)

“…Sakai and Osakabe (2010) found that the distribution of T. urticae females was different between upper and lower leaf surfaces as a result of UV-avoidance behavior. The deleterious effects of solar UVR may be significant factors restricting plant-dwelling mites, including predacious mites, to the lower leaf surfaces or inside domatia (Ohtsuka and Osakabe 2009;Onzo et al 2010;Sudo and Osakabe 2011). These species might occupy habitat in which they encounter predators or competitors less frequently or gain nutritional advantage through increased fecundity on the upper leaf surfaces versus the lower leaf surfaces.…”

“…These species might occupy habitat in which they encounter predators or competitors less frequently or gain nutritional advantage through increased fecundity on the upper leaf surfaces versus the lower leaf surfaces. In fact, a part of herbivorous mites exploit not only the lower but also the upper leaf surfaces of host plants (Foott 1963;Jones and Parrella 1984;Sudo and Osakabe 2011). Of those species, the European red mite Panonychus ulmi (Koch) (Acari: Tetranychidae), moves from the lower to the upper leaf surfaces as a response to increasing density of a superior competitor T. urticae on the lower leaf surfaces (Osakabe et al 2006).…”

“…The small body sizes of plant-dwelling mites may be disadvantageous for protecting them against UVR damage. Such damage may alter their behavior and niche exploitation (Onzo et al 2010;Sudo and Osakabe 2011), and in turn, their population dynamics and the composition of foliar communities.…”

An Insect with Selective Control of Egg Coloration

“…In contrast, most plant-dwelling arthropods, including many species of stink bugs, tend to lay their eggs on the undersides of plant leaves [17][18][19][20]. Laying eggs on the undersides of leaves is generally considered to provide a sheltered microclimate for developing embryos, offering protection against wind, rain, overheating, and desiccation.…”

Spectrum-Specific Uv Egg Damage and Dispersal Responses in the Phytoseiid Predatory MiteNeoseiulus californicus(Acari: Phytoseiidae)

“…Many plant-dwelling mites preferentially inhabit lower rather than upper leaf surfaces of their host plants (Sudo and Osakabe 2011). Solar ultraviolet-B (UVB; 280 Ð315 nm wavelengths) radiation may be a major factor affecting the within-leaf (upper/lower) distribution of mites (Ohtsuka and Osakabe 2009, Suzuki et al 2009, Sakai and Osakabe 2010.…”