Morphological variation in leaf domatia enables coexistence of antagonistic mites in Cinnamomum camphora

Abstract

We examined variation in Cinnamomum camphora (L.) J. Presl (Lauraceae) leaf domatium morphology with respect to domatium inhabitants in the tree's natural habitats. Canonical discriminant analysis revealed that domatium morphology could be classified into four different types: pouch type, domatia with a narrow (about 0.06 mm) pubescent opening; pubescent pit type, domatia with a wider (about 0.21 mm) pubescent opening; glabrous pit type, domatia similar to the pubescent pit type but with a glabrous opening; and dish type, domatia with a wide (about 0.26 mm) glabrous opening. These four domatium types were found in different positions on a leaf, and domatia with narrower openings tended to occur in or near the position between the midrib and basal secondary veins. The four domatium types were associated, respectively, with herbivorous Eriophyidae mites and herbivorous or fungivorous Tarsonemidae mites; with carnivorous Stigmaeidae mites; with Stigmaeidae mites and egg shells or excuviae of carnivorous Phytoseiidae mites; and with egg shells or excuviae of Phytoseiidae mites. These results suggest that different mites use different domatia, even on the same C. camphora leaf. This conclusion may explain the different results in previous reports about domatium fauna. It suggests that ecological interactions within the plant–herbivore–carnivore system are complicated.Key words: carnivorous mite, Cinnamomum camphora, domatia, herbivorous mite, inhabitant, morphology.

Mites and leaf domatia: no evidence of mutualism in Coffea arabica plants

“…observ.). Nishida et al (2005) have found habitat segregation among mites of different sizes (i.e. taxonomic groups), i.e., whereas smaller mites inhabited the smaller domatia of Cinnamomum camphora (L.), an inverse pattern occurred for larger mites, which inhabited larger domatia.…”

“…Their most common shapes are pit (i.e., invaginations of leaf surface that reach the mesophyll), pocket (cavities beneath expanded veins), dense hair-tufts, or an association between hair-tufts and pits or pockets (O'Dowd & Willson 1989, Nishida et al 2005. The main inhabitants of leaf domatia are mites, especially predators of the families Phytoseiidae and Stigmaeidae; fungivores of the groups Tarsonemidae, Winterschmidtiidae and Oribatida are also typically common (revised in Romero & Benson 2005).…”

Mites on Plants

“…On saplings of the South American rainforest tree Cupania vernalis (Sapindaceae), Romero and Benson ( 2004 ) found that eriophyoids were the most common mites in domatia and far more common on leaves with open as opposed to blocked domatia, although without obvious damage to the plants. Nishida et al ( 2005 ) also found eriophyoid mites the most common group in the domatia of Camphor Laurel, although when predatory phytoseiid mites were present eriophyoids were found only in domatia with openings too small for the 8 Mites on Plants 309 predators. During outbreaks of eriophyoids in Queensland rainforests, the leaf undersides including any domatia present can harbour large numbers of eriophyoid mites, but this is usually a transient phenomenon: eriophyoid numbers quickly drop (presumably due to predation) and domatia are rarely galled.…”

“…Cryptocarya , Lauraceae), certain species have simple tuft domatia, while others have more elaborate domes or pockets in the same location. An even greater diversity of domatial forms can be found in shrubs in the genus Viburnum (Adoxaceae) (Weber et al 2012 ) anda diversity of forms can be wound even within a single leaf (Nishida et al 2005 ). This pattern of differently formed structures found in the same position in related species is moderately strong evidence for functional homology with a genetic basis.…”

“…An exception is discussed below, but some reports in the literature of 'herbivorous' mites inhabiting domatia are of tydeid or tarsonemid mites with obscure feeding habits. For example, Nishida et al ( 2005 ) found "herbivorous or fungivorous Tarsonemidae mites" the second most common inhabitants of the domatia of Camphor Laurel ( Cinnamomum camphora , Lauraceae). The ( Fig.…”