Symptoms of Osmanthus Leaf Blight  
　　
    : It occurs on the leaf margins and tips. Initially, it appears as small, light brown spots, which gradually enlarge into large, irregular patches. If several lesions merge, 1/3 to 1/2 of the entire leaf will dry out. The lesions are grayish-brown to reddish-brown, sometimes brittle, with darker, slightly raised edges. In later stages, many small black dots appear scattered on the affected area, while the underside of the lesions is lighter in color.  
　　
    Transmission: The pathogen overwinters as mycelium or conidiophores in diseased leaves and fallen leaves. Conidia are spread by wind and rain. The optimal temperature for pathogen development is around 27℃. The disease is more severe in humid, hot, and poorly ventilated environments, or when the plant is weak. It occurs more frequently on older leaves after winter and is more common on the lower leaves.  
　　
    Control Methods: 
　　
    1. Horticultural Control: Strengthen cultivation and management. Avoid waterlogging in potted Osmanthus. Increase the application of humus fertilizer and potassium fertilizer to improve disease resistance. 1. Remove diseased leaves from diseased plants promptly. In winter, also remove fallen diseased leaves to prevent further infection.  
　　
    2. Chemical control: During the initial stage of disease, spray with a 1:2:100 dilution of Bordeaux mixture (lime-based). Later, spray with a 1000-1500 dilution of 50% benomyl wettable powder or an 800-1000 dilution of 50% carbendazim.  
　　
    3. The main insect pest of Osmanthus fragrans 
　　
    is the jewel beetle　 
　　
    . The larvae bore into the bark of the branches and trunk, exuding an oily, brownish sap. Severe infestations cause the bark to crack, leading to the death of main branches or the entire tree. Adults bite and notch tender leaves, causing significant leaf drop. Poorly managed and weak trees are more severely affected. During the peak larval hatching period (generally May), scrape off the bark and apply a 20-fold dilution of 80% dichlorvos emulsion. During the adult emergence period (around June), spray the canopy 2-3 times with a 1000-fold dilution of 90% trichlorfon.  
　　
    Scale　 
　　
    insects that damage osmanthus include red wax scale, cottony cushion scale, and chaff scale. Both nymphs and adults use their stylets to pierce the tissues of branches and trunks to suck sap, causing the branches and leaves to wither and die. They also secrete honeydew, inducing sooty mold, which causes severe damage. Control can be achieved by spraying with a 2500-fold dilution of 20% cypermethrin EC or 2.5% deltamethrin EC during the nymph hatching period; and by spraying with a 1500-fold dilution of 40% cypermethrin EC during scale formation, as its strong penetrability provides good control.  
　　
    Tussock moths　 
　　
    mainly include yellow tussock moths, green tussock moths, blue tussock moths, and flat tussock moths. They mostly overwinter as larvae in cocoons. Young larvae congregate to feed on leaves, with the heaviest feeding occurring from July to September. Adults are strongly attracted to light. From May to June, use black light lamps to trap and kill adult insects; manually remove cocoons attached to branches and trunks; and promptly carry out chemical control during the early larval stages, using 10% cypermethrin at a dilution of 2000 times or 90% trichlorfon at a dilution of 1000 times to spray and kill larvae.