What is leaf spot disease caused by fungi of the genus Phyllosticta?

This disease has been found in Australia, the United States, India, Japan, Mexico, the Philippines and other places, and theorchidsit harms are numerous, mainly including: Trichoglottis, spider orchid, Cattleya, Cymbidium, Dendrobium, Laelia, Odontoglossum, Oncidium, Paphiopedilum, Phalaenopsis, Renanthera, Vanda, Vanilla, and Spathoglottis, etc. Its pathogen has been identified as: Phyllostictina pyriformis. In the early stage of infection, single lesions first appear on the leaves and pseudobulbs. The lesions are tiny, yellow and slightly sunken. As the lesions expand, the spots become depressed, especially conspicuously depressed on the leaves, and the color changes to brown to dark brown, while the edges are raised, red to purplish black. A single lesion is round to oval, but when two or more lesions merge together they form irregular patches. Lesions on the pseudobulbs are mostly oval and distributed longitudinally, with a single lesion having an average diameter of about 0.6 cm, but in many cases they are also somewhat smaller or much larger. Finally, tiny raised black dots appear in the brown or brown areas of the lesions; these are the pathogen's pycnidia, which contain the pathogen's conidia. For the control of this disease, benomyl 50% wettable powder can be mixed into a medicinal solution for spraying, once every two weeks, 3 times in total, at a concentration of 1000 times dilution, with a wetting agent added. Ferbam or chlorothalonil 2787 can also be used, applied twice a month at a concentration of 800 times dilution. Remove and destroy all infected parts; this measure helps protect tissues that have not yet been infected. (Liu Zhongjian)