MITE ASSOCIATION WITH THE LEAF DOMATIA OF COFFEE (COFFEA-ARABICA) IN NORTH QUEENSLAND, AUSTRALIA

The primary coffee of commerce, Coffea arabica, has well-developed pit domatia in the primary vein axils on the undersurfaces of the leaves. In plantations near Mareeba and Daintree in far north Queensland, Australia, these morphogenetic structures are commonly occupied by mites. Mites used domatia on over 80% of all leaves examined, and 41% of all domatia had been occupied by mites (15-28% on young leaves and 54-59% on older leaves at Mareeba, and 58% overall at Daintree). At Mareeba, domatia use by mites did not differ among plants or shoots within plants but did vary significantly with leaf position within shoots, a reflection of leaf age. Domatia were important sites for mite reproduction and development; 93% of the eggs and all moulting mites on leaves were in domatia. Seven mite taxa were identified on leaves at Mareeba and nine were present at Daintree. With the exception of Fungitarsonemus sp. and Brevipalpus obovatus Donnadieu at Mareeba, all were concentrated in leaf domatia. Almost all mites in domatia were from groups in which arboreal representatives are primarily predatory (e.g., Stigmaeidae, Phytoseiidae, and Bdellidae), fungivorous (e.g., Winterschmidtiidae, Oribatida and Acaridae), or both (Tydeidae and Tarsonemidae). The data suggest that domatia influence the distribution and abundance of predatory and fungivorous mites that have the potential to affect fungal pathogens and some arthropod pests on coffee leaves.